diff --git a/src/hosts/core/config.py b/src/hosts/core/config.py
index fea36d5..82be9a1 100644
--- a/src/hosts/core/config.py
+++ b/src/hosts/core/config.py
@@ -12,16 +12,16 @@ from typing import Dict, Any
 class Config:
     """
     Configuration manager for the hosts application.
-    
+
     Handles loading, saving, and managing application settings.
     """
-    
+
     def __init__(self):
         self.config_dir = Path.home() / ".config" / "hosts-manager"
         self.config_file = self.config_dir / "config.json"
         self._settings = self._load_default_settings()
         self.load()
-    
+
     def _load_default_settings(self) -> Dict[str, Any]:
         """Load default configuration settings."""
         return {
@@ -34,41 +34,41 @@ class Config:
             "window_settings": {
                 "last_sort_column": "",
                 "last_sort_ascending": True,
-            }
+            },
         }
-    
+
     def load(self) -> None:
         """Load configuration from file."""
         try:
             if self.config_file.exists():
-                with open(self.config_file, 'r') as f:
+                with open(self.config_file, "r") as f:
                     loaded_settings = json.load(f)
                     # Merge with defaults to ensure all keys exist
                     self._settings.update(loaded_settings)
         except (json.JSONDecodeError, IOError):
             # If loading fails, use defaults
             pass
-    
+
     def save(self) -> None:
         """Save configuration to file."""
         try:
             # Ensure config directory exists
             self.config_dir.mkdir(parents=True, exist_ok=True)
-            
-            with open(self.config_file, 'w') as f:
+
+            with open(self.config_file, "w") as f:
                 json.dump(self._settings, f, indent=2)
         except IOError:
             # Silently fail if we can't save config
             pass
-    
+
     def get(self, key: str, default: Any = None) -> Any:
         """Get a configuration value."""
         return self._settings.get(key, default)
-    
+
     def set(self, key: str, value: Any) -> None:
         """Set a configuration value."""
         self._settings[key] = value
-    
+
     def is_default_entry(self, ip_address: str, hostname: str) -> bool:
         """Check if an entry is a default system entry."""
         default_entries = self.get("default_entries", [])
@@ -76,11 +76,11 @@ class Config:
             if entry["ip"] == ip_address and entry["hostname"] == hostname:
                 return True
         return False
-    
+
     def should_show_default_entries(self) -> bool:
         """Check if default entries should be shown."""
         return self.get("show_default_entries", False)
-    
+
     def toggle_show_default_entries(self) -> None:
         """Toggle the show default entries setting."""
         current = self.get("show_default_entries", False)
diff --git a/src/hosts/core/manager.py b/src/hosts/core/manager.py
index 905e466..1b44c38 100644
--- a/src/hosts/core/manager.py
+++ b/src/hosts/core/manager.py
@@ -17,85 +17,95 @@ from .parser import HostsParser
 class PermissionManager:
     """
     Manages sudo permissions for hosts file editing.
-    
+
     Handles requesting, validating, and releasing elevated permissions
     needed for modifying the system hosts file.
     """
-    
+
     def __init__(self):
         self.has_sudo = False
         self._sudo_validated = False
-    
-    def request_sudo(self) -> Tuple[bool, str]:
+
+    def request_sudo(self, password: str = None) -> Tuple[bool, str]:
         """
         Request sudo permissions for hosts file editing.
-        
+
+        Args:
+            password: Optional password for sudo authentication
+
         Returns:
             Tuple of (success, message)
         """
         try:
             # Test sudo access with a simple command
             result = subprocess.run(
-                ['sudo', '-n', 'true'],
-                capture_output=True,
-                text=True,
-                timeout=5
+                ["sudo", "-n", "true"], capture_output=True, text=True, timeout=5
             )
-            
+
             if result.returncode == 0:
                 # Already have sudo access
                 self.has_sudo = True
                 self._sudo_validated = True
                 return True, "Sudo access already available"
-            
-            # Need to prompt for password
+
+            # If no password provided, indicate we need password input
+            if password is None:
+                return False, "Password required for sudo access"
+
+            # Use password for sudo authentication
             result = subprocess.run(
-                ['sudo', '-v'],
+                ["sudo", "-S", "-v"],
+                input=password + "\n",
                 capture_output=True,
                 text=True,
-                timeout=30
+                timeout=10,
             )
-            
+
             if result.returncode == 0:
                 self.has_sudo = True
                 self._sudo_validated = True
                 return True, "Sudo access granted"
             else:
-                return False, "Sudo access denied"
-                
+                # Check if it's a password error
+                if (
+                    "incorrect password" in result.stderr.lower()
+                    or "authentication failure" in result.stderr.lower()
+                ):
+                    return False, "Incorrect password"
+                else:
+                    return False, f"Sudo access denied: {result.stderr}"
+
         except subprocess.TimeoutExpired:
             return False, "Sudo request timed out"
         except Exception as e:
             return False, f"Error requesting sudo: {e}"
-    
+
     def validate_permissions(self, file_path: str = "/etc/hosts") -> bool:
         """
         Validate that we have write permissions to the hosts file.
-        
+
         Args:
             file_path: Path to the hosts file
-            
+
         Returns:
             True if we can write to the file
         """
         if not self.has_sudo:
             return False
-        
+
         try:
             # Test write access with sudo
             result = subprocess.run(
-                ['sudo', '-n', 'test', '-w', file_path],
-                capture_output=True,
-                timeout=5
+                ["sudo", "-n", "test", "-w", file_path], capture_output=True, timeout=5
             )
             return result.returncode == 0
         except Exception:
             return False
-    
+
     def release_sudo(self) -> None:
         """Release sudo permissions."""
         try:
-            subprocess.run(['sudo', '-k'], capture_output=True, timeout=5)
+            subprocess.run(["sudo", "-k"], capture_output=True, timeout=5)
         except Exception:
             pass
         finally:
@@ -106,36 +116,39 @@ class PermissionManager:
 class HostsManager:
     """
     Main manager for hosts file edit operations.
-    
+
     Provides high-level operations for modifying hosts file entries
     with proper permission management, validation, and backup.
     """
-    
+
     def __init__(self, file_path: str = "/etc/hosts"):
         self.parser = HostsParser(file_path)
         self.permission_manager = PermissionManager()
         self.edit_mode = False
         self._backup_path: Optional[Path] = None
-    
-    def enter_edit_mode(self) -> Tuple[bool, str]:
+
+    def enter_edit_mode(self, password: str = None) -> Tuple[bool, str]:
         """
         Enter edit mode with proper permission management.
-        
+
+        Args:
+            password: Optional password for sudo authentication
+
         Returns:
             Tuple of (success, message)
         """
         if self.edit_mode:
             return True, "Already in edit mode"
-        
+
         # Request sudo permissions
-        success, message = self.permission_manager.request_sudo()
+        success, message = self.permission_manager.request_sudo(password)
         if not success:
-            return False, f"Cannot enter edit mode: {message}"
-        
+            return False, message
+
         # Validate write permissions
         if not self.permission_manager.validate_permissions(str(self.parser.file_path)):
             return False, "Cannot write to hosts file even with sudo"
-        
+
         # Create backup
         try:
             self._create_backup()
@@ -143,17 +156,17 @@ class HostsManager:
             return True, "Edit mode enabled"
         except Exception as e:
             return False, f"Failed to create backup: {e}"
-    
+
     def exit_edit_mode(self) -> Tuple[bool, str]:
         """
         Exit edit mode and release permissions.
-        
+
         Returns:
             Tuple of (success, message)
         """
         if not self.edit_mode:
             return True, "Already in read-only mode"
-        
+
         try:
             self.permission_manager.release_sudo()
             self.edit_mode = False
@@ -161,265 +174,282 @@ class HostsManager:
             return True, "Edit mode disabled"
         except Exception as e:
             return False, f"Error exiting edit mode: {e}"
-    
+
     def toggle_entry(self, hosts_file: HostsFile, index: int) -> Tuple[bool, str]:
         """
         Toggle the active state of an entry.
-        
+
         Args:
             hosts_file: The hosts file to modify
             index: Index of the entry to toggle
-            
+
         Returns:
             Tuple of (success, message)
         """
         if not self.edit_mode:
             return False, "Not in edit mode"
-        
+
         if not (0 <= index < len(hosts_file.entries)):
             return False, "Invalid entry index"
-        
+
         try:
             entry = hosts_file.entries[index]
-            
+
             # Prevent modification of default system entries
             if entry.is_default_entry():
                 return False, "Cannot modify default system entries"
-            
+
             old_state = "active" if entry.is_active else "inactive"
             entry.is_active = not entry.is_active
             new_state = "active" if entry.is_active else "inactive"
-            
+
             return True, f"Entry toggled from {old_state} to {new_state}"
         except Exception as e:
             return False, f"Error toggling entry: {e}"
-    
+
     def move_entry_up(self, hosts_file: HostsFile, index: int) -> Tuple[bool, str]:
         """
         Move an entry up in the list.
-        
+
         Args:
             hosts_file: The hosts file to modify
             index: Index of the entry to move
-            
+
         Returns:
             Tuple of (success, message)
         """
         if not self.edit_mode:
             return False, "Not in edit mode"
-        
+
         if index <= 0 or index >= len(hosts_file.entries):
             return False, "Cannot move entry up"
-        
+
         try:
             entry = hosts_file.entries[index]
             target_entry = hosts_file.entries[index - 1]
-            
+
             # Prevent moving default system entries or moving entries above default entries
             if entry.is_default_entry() or target_entry.is_default_entry():
                 return False, "Cannot move default system entries"
-            
+
             # Swap with previous entry
-            hosts_file.entries[index], hosts_file.entries[index - 1] = \
-                hosts_file.entries[index - 1], hosts_file.entries[index]
+            hosts_file.entries[index], hosts_file.entries[index - 1] = (
+                hosts_file.entries[index - 1],
+                hosts_file.entries[index],
+            )
             return True, "Entry moved up"
         except Exception as e:
             return False, f"Error moving entry: {e}"
-    
+
     def move_entry_down(self, hosts_file: HostsFile, index: int) -> Tuple[bool, str]:
         """
         Move an entry down in the list.
-        
+
         Args:
             hosts_file: The hosts file to modify
             index: Index of the entry to move
-            
+
         Returns:
             Tuple of (success, message)
         """
         if not self.edit_mode:
             return False, "Not in edit mode"
-        
+
         if index < 0 or index >= len(hosts_file.entries) - 1:
             return False, "Cannot move entry down"
-        
+
         try:
             entry = hosts_file.entries[index]
             target_entry = hosts_file.entries[index + 1]
-            
+
             # Prevent moving default system entries or moving entries below default entries
             if entry.is_default_entry() or target_entry.is_default_entry():
                 return False, "Cannot move default system entries"
-            
+
             # Swap with next entry
-            hosts_file.entries[index], hosts_file.entries[index + 1] = \
-                hosts_file.entries[index + 1], hosts_file.entries[index]
+            hosts_file.entries[index], hosts_file.entries[index + 1] = (
+                hosts_file.entries[index + 1],
+                hosts_file.entries[index],
+            )
             return True, "Entry moved down"
         except Exception as e:
             return False, f"Error moving entry: {e}"
-    
-    def update_entry(self, hosts_file: HostsFile, index: int, 
-                    ip_address: str, hostnames: list[str], 
-                    comment: Optional[str] = None) -> Tuple[bool, str]:
+
+    def update_entry(
+        self,
+        hosts_file: HostsFile,
+        index: int,
+        ip_address: str,
+        hostnames: list[str],
+        comment: Optional[str] = None,
+    ) -> Tuple[bool, str]:
         """
         Update an existing entry.
-        
+
         Args:
             hosts_file: The hosts file to modify
             index: Index of the entry to update
             ip_address: New IP address
             hostnames: New list of hostnames
             comment: New comment (optional)
-            
+
         Returns:
             Tuple of (success, message)
         """
         if not self.edit_mode:
             return False, "Not in edit mode"
-        
+
         if not (0 <= index < len(hosts_file.entries)):
             return False, "Invalid entry index"
-        
+
         try:
             entry = hosts_file.entries[index]
-            
+
             # Prevent modification of default system entries
             if entry.is_default_entry():
                 return False, "Cannot modify default system entries"
-            
+
             # Create new entry to validate
             new_entry = HostEntry(
                 ip_address=ip_address,
                 hostnames=hostnames,
                 comment=comment,
                 is_active=hosts_file.entries[index].is_active,
-                dns_name=hosts_file.entries[index].dns_name
+                dns_name=hosts_file.entries[index].dns_name,
             )
-            
+
             # Replace the entry
             hosts_file.entries[index] = new_entry
             return True, "Entry updated successfully"
-            
+
         except ValueError as e:
             return False, f"Invalid entry data: {e}"
         except Exception as e:
             return False, f"Error updating entry: {e}"
-    
+
     def save_hosts_file(self, hosts_file: HostsFile) -> Tuple[bool, str]:
         """
         Save the hosts file to disk with sudo permissions.
-        
+
         Args:
             hosts_file: The hosts file to save
-            
+
         Returns:
             Tuple of (success, message)
         """
         if not self.edit_mode:
             return False, "Not in edit mode"
-        
+
         if not self.permission_manager.has_sudo:
             return False, "No sudo permissions"
-        
+
         try:
             # Serialize the hosts file
             content = self.parser.serialize(hosts_file)
-            
+
             # Write to temporary file first
-            with tempfile.NamedTemporaryFile(mode='w', delete=False, suffix='.hosts') as temp_file:
+            with tempfile.NamedTemporaryFile(
+                mode="w", delete=False, suffix=".hosts"
+            ) as temp_file:
                 temp_file.write(content)
                 temp_path = temp_file.name
-            
+
             try:
                 # Use sudo to copy the temp file to the hosts file
                 result = subprocess.run(
-                    ['sudo', 'cp', temp_path, str(self.parser.file_path)],
+                    ["sudo", "cp", temp_path, str(self.parser.file_path)],
                     capture_output=True,
                     text=True,
-                    timeout=10
+                    timeout=10,
                 )
-                
+
                 if result.returncode == 0:
                     return True, "Hosts file saved successfully"
                 else:
                     return False, f"Failed to save hosts file: {result.stderr}"
-                    
+
             finally:
                 # Clean up temp file
                 try:
                     os.unlink(temp_path)
                 except Exception:
                     pass
-                    
+
         except Exception as e:
             return False, f"Error saving hosts file: {e}"
-    
+
     def restore_backup(self) -> Tuple[bool, str]:
         """
         Restore the hosts file from backup.
-        
+
         Returns:
             Tuple of (success, message)
         """
         if not self.edit_mode:
             return False, "Not in edit mode"
-        
+
         if not self._backup_path or not self._backup_path.exists():
             return False, "No backup available"
-        
+
         try:
             result = subprocess.run(
-                ['sudo', 'cp', str(self._backup_path), str(self.parser.file_path)],
+                ["sudo", "cp", str(self._backup_path), str(self.parser.file_path)],
                 capture_output=True,
                 text=True,
-                timeout=10
+                timeout=10,
             )
-            
+
             if result.returncode == 0:
                 return True, "Backup restored successfully"
             else:
                 return False, f"Failed to restore backup: {result.stderr}"
-                
+
         except Exception as e:
             return False, f"Error restoring backup: {e}"
-    
+
     def _create_backup(self) -> None:
         """Create a backup of the current hosts file."""
         if not self.parser.file_path.exists():
             return
-        
+
         # Create backup in temp directory
         backup_dir = Path(tempfile.gettempdir()) / "hosts-manager-backups"
         backup_dir.mkdir(exist_ok=True)
-        
+
         import time
+
         timestamp = int(time.time())
         self._backup_path = backup_dir / f"hosts.backup.{timestamp}"
-        
+
         # Copy current hosts file to backup
         result = subprocess.run(
-            ['sudo', 'cp', str(self.parser.file_path), str(self._backup_path)],
+            ["sudo", "cp", str(self.parser.file_path), str(self._backup_path)],
             capture_output=True,
-            timeout=10
+            timeout=10,
         )
-        
+
         if result.returncode != 0:
             raise Exception(f"Failed to create backup: {result.stderr}")
-        
+
         # Make backup readable by user
-        subprocess.run(['sudo', 'chmod', '644', str(self._backup_path)], capture_output=True)
+        subprocess.run(
+            ["sudo", "chmod", "644", str(self._backup_path)], capture_output=True
+        )
 
 
 class EditModeError(Exception):
     """Base exception for edit mode errors."""
+
     pass
 
 
 class PermissionError(EditModeError):
     """Raised when there are permission issues."""
+
     pass
 
 
 class ValidationError(EditModeError):
     """Raised when validation fails."""
+
     pass
diff --git a/src/hosts/core/models.py b/src/hosts/core/models.py
index 35ec529..e914c8b 100644
--- a/src/hosts/core/models.py
+++ b/src/hosts/core/models.py
@@ -15,7 +15,7 @@ import re
 class HostEntry:
     """
     Represents a single entry in the hosts file.
-    
+
     Attributes:
         ip_address: The IP address (IPv4 or IPv6)
         hostnames: List of hostnames mapped to this IP
@@ -23,6 +23,7 @@ class HostEntry:
         is_active: Whether this entry is active (not commented out)
         dns_name: Optional DNS name for CNAME-like functionality
     """
+
     ip_address: str
     hostnames: List[str]
     comment: Optional[str] = None
@@ -36,29 +37,32 @@ class HostEntry:
     def is_default_entry(self) -> bool:
         """
         Check if this entry is a system default entry.
-        
+
         Returns:
             True if this is a default system entry (localhost, broadcasthost, ::1)
         """
         if not self.hostnames:
             return False
-        
+
         canonical_hostname = self.hostnames[0]
         default_entries = [
             {"ip": "127.0.0.1", "hostname": "localhost"},
             {"ip": "255.255.255.255", "hostname": "broadcasthost"},
             {"ip": "::1", "hostname": "localhost"},
         ]
-        
+
         for entry in default_entries:
-            if entry["ip"] == self.ip_address and entry["hostname"] == canonical_hostname:
+            if (
+                entry["ip"] == self.ip_address
+                and entry["hostname"] == canonical_hostname
+            ):
                 return True
         return False
 
     def validate(self) -> None:
         """
         Validate the host entry data.
-        
+
         Raises:
             ValueError: If the IP address or hostnames are invalid
         """
@@ -73,9 +77,9 @@ class HostEntry:
             raise ValueError("At least one hostname is required")
 
         hostname_pattern = re.compile(
-            r'^[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?(\.[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?)*$'
+            r"^[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?(\.[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?)*$"
         )
-        
+
         for hostname in self.hostnames:
             if not hostname_pattern.match(hostname):
                 raise ValueError(f"Invalid hostname '{hostname}'")
@@ -83,39 +87,41 @@ class HostEntry:
     def to_hosts_line(self, ip_width: int = 0, hostname_width: int = 0) -> str:
         """
         Convert this entry to a hosts file line with proper tab alignment.
-        
+
         Args:
             ip_width: Width of the IP address column for alignment
             hostname_width: Width of the canonical hostname column for alignment
-        
+
         Returns:
             String representation suitable for writing to hosts file
         """
         line_parts = []
-        
+
         # Build the IP address part (with comment prefix if inactive)
         ip_part = ""
         if not self.is_active:
             ip_part = "# "
         ip_part += self.ip_address
-        
+
         # Calculate tabs needed for IP column alignment
         ip_tabs = self._calculate_tabs_needed(len(ip_part), ip_width)
-        
+
         # Build the canonical hostname part
         canonical_hostname = self.hostnames[0] if self.hostnames else ""
-        hostname_tabs = self._calculate_tabs_needed(len(canonical_hostname), hostname_width)
-        
+        hostname_tabs = self._calculate_tabs_needed(
+            len(canonical_hostname), hostname_width
+        )
+
         # Start building the line
         line_parts.append(ip_part)
         line_parts.append("\t" * max(1, ip_tabs))  # At least one tab
         line_parts.append(canonical_hostname)
-        
+
         # Add additional hostnames (aliases) with single tab separation
         if len(self.hostnames) > 1:
             line_parts.append("\t" * max(1, hostname_tabs))
             line_parts.append("\t".join(self.hostnames[1:]))
-        
+
         # Add comment if present
         if self.comment:
             if len(self.hostnames) <= 1:
@@ -123,23 +129,23 @@ class HostEntry:
             else:
                 line_parts.append("\t")
             line_parts.append(f"# {self.comment}")
-        
+
         return "".join(line_parts)
-    
+
     def _calculate_tabs_needed(self, current_length: int, target_width: int) -> int:
         """
         Calculate number of tabs needed to reach target column width.
-        
+
         Args:
             current_length: Current string length
             target_width: Target column width
-            
+
         Returns:
             Number of tabs needed (minimum 1)
         """
         if target_width <= current_length:
             return 1
-        
+
         # Calculate tabs needed (assuming tab width of 8)
         tab_width = 8
         remaining_space = target_width - current_length
@@ -147,59 +153,60 @@ class HostEntry:
         return max(1, tabs_needed)
 
     @classmethod
-    def from_hosts_line(cls, line: str) -> Optional['HostEntry']:
+    def from_hosts_line(cls, line: str) -> Optional["HostEntry"]:
         """
         Parse a hosts file line into a HostEntry.
-        
+
         Args:
             line: A line from the hosts file
-            
+
         Returns:
             HostEntry instance or None if line is empty/comment-only
         """
         original_line = line.strip()
         if not original_line:
             return None
-        
+
         # Check if line is commented out (inactive)
         is_active = True
-        if original_line.startswith('#'):
+        if original_line.startswith("#"):
             is_active = False
             line = original_line[1:].strip()
-        
+
         # Handle comment-only lines
-        if not line or line.startswith('#'):
+        if not line or line.startswith("#"):
             return None
-        
+
         # Split line into parts, handling both spaces and tabs
         import re
+
         # Split on any whitespace (spaces, tabs, or combinations)
-        parts = re.split(r'\s+', line.strip())
+        parts = re.split(r"\s+", line.strip())
         if len(parts) < 2:
             return None
-        
+
         ip_address = parts[0]
         hostnames = []
         comment = None
-        
+
         # Parse hostnames and comments
         for i, part in enumerate(parts[1:], 1):
-            if part.startswith('#'):
+            if part.startswith("#"):
                 # Everything from here is a comment
-                comment = ' '.join(parts[i:]).lstrip('# ')
+                comment = " ".join(parts[i:]).lstrip("# ")
                 break
             else:
                 hostnames.append(part)
-        
+
         if not hostnames:
             return None
-        
+
         try:
             return cls(
                 ip_address=ip_address,
                 hostnames=hostnames,
                 comment=comment,
-                is_active=is_active
+                is_active=is_active,
             )
         except ValueError:
             # Skip invalid entries
@@ -210,12 +217,13 @@ class HostEntry:
 class HostsFile:
     """
     Represents the complete hosts file structure.
-    
+
     Attributes:
         entries: List of host entries
         header_comments: Comments at the beginning of the file
         footer_comments: Comments at the end of the file
     """
+
     entries: List[HostEntry] = field(default_factory=list)
     header_comments: List[str] = field(default_factory=list)
     footer_comments: List[str] = field(default_factory=list)
@@ -246,24 +254,26 @@ class HostsFile:
     def sort_by_ip(self, ascending: bool = True) -> None:
         """
         Sort entries by IP address, keeping default entries on top in fixed order.
-        
+
         Args:
             ascending: Sort in ascending order if True, descending if False
         """
         # Separate default and non-default entries
         default_entries = [entry for entry in self.entries if entry.is_default_entry()]
-        non_default_entries = [entry for entry in self.entries if not entry.is_default_entry()]
-        
+        non_default_entries = [
+            entry for entry in self.entries if not entry.is_default_entry()
+        ]
+
         def ip_sort_key(entry):
             try:
-                ip_str = entry.ip_address.lstrip('# ')
+                ip_str = entry.ip_address.lstrip("# ")
                 ip_obj = ipaddress.ip_address(ip_str)
                 # Create a tuple for sorting: (version, ip_int)
                 return (ip_obj.version, int(ip_obj))
             except ValueError:
                 # If IP parsing fails, use string comparison
                 return (999, entry.ip_address)
-        
+
         # Keep default entries in their natural fixed order (don't sort them)
         # Define the fixed order for default entries
         default_order = [
@@ -271,38 +281,43 @@ class HostsFile:
             {"ip": "255.255.255.255", "hostname": "broadcasthost"},
             {"ip": "::1", "hostname": "localhost"},
         ]
-        
+
         # Sort default entries according to their fixed order
         def default_sort_key(entry):
             for i, default in enumerate(default_order):
-                if (entry.ip_address == default["ip"] and 
-                    entry.hostnames and entry.hostnames[0] == default["hostname"]):
+                if (
+                    entry.ip_address == default["ip"]
+                    and entry.hostnames
+                    and entry.hostnames[0] == default["hostname"]
+                ):
                     return i
             return 999  # fallback for any unexpected default entries
-        
+
         default_entries.sort(key=default_sort_key)
-        
+
         # Sort non-default entries according to the specified direction
         non_default_entries.sort(key=ip_sort_key, reverse=not ascending)
-        
+
         # Combine: default entries always first, then sorted non-default entries
         self.entries = default_entries + non_default_entries
 
     def sort_by_hostname(self, ascending: bool = True) -> None:
         """
         Sort entries by first hostname, keeping default entries on top in fixed order.
-        
+
         Args:
             ascending: Sort in ascending order if True, descending if False
         """
         # Separate default and non-default entries
         default_entries = [entry for entry in self.entries if entry.is_default_entry()]
-        non_default_entries = [entry for entry in self.entries if not entry.is_default_entry()]
-        
+        non_default_entries = [
+            entry for entry in self.entries if not entry.is_default_entry()
+        ]
+
         def hostname_sort_key(entry):
             hostname = (entry.hostnames[0] if entry.hostnames else "").lower()
             return hostname
-        
+
         # Keep default entries in their natural fixed order (don't sort them)
         # Define the fixed order for default entries
         default_order = [
@@ -310,30 +325,33 @@ class HostsFile:
             {"ip": "255.255.255.255", "hostname": "broadcasthost"},
             {"ip": "::1", "hostname": "localhost"},
         ]
-        
+
         # Sort default entries according to their fixed order
         def default_sort_key(entry):
             for i, default in enumerate(default_order):
-                if (entry.ip_address == default["ip"] and 
-                    entry.hostnames and entry.hostnames[0] == default["hostname"]):
+                if (
+                    entry.ip_address == default["ip"]
+                    and entry.hostnames
+                    and entry.hostnames[0] == default["hostname"]
+                ):
                     return i
             return 999  # fallback for any unexpected default entries
-        
+
         default_entries.sort(key=default_sort_key)
-        
+
         # Sort non-default entries according to the specified direction
         non_default_entries.sort(key=hostname_sort_key, reverse=not ascending)
-        
+
         # Combine: default entries always first, then sorted non-default entries
         self.entries = default_entries + non_default_entries
 
     def find_entries_by_hostname(self, hostname: str) -> List[int]:
         """
         Find entry indices that contain the given hostname.
-        
+
         Args:
             hostname: Hostname to search for
-            
+
         Returns:
             List of indices where the hostname is found
         """
@@ -346,10 +364,10 @@ class HostsFile:
     def find_entries_by_ip(self, ip_address: str) -> List[int]:
         """
         Find entry indices that have the given IP address.
-        
+
         Args:
             ip_address: IP address to search for
-            
+
         Returns:
             List of indices where the IP is found
         """
diff --git a/src/hosts/core/parser.py b/src/hosts/core/parser.py
index 5407a84..08b219c 100644
--- a/src/hosts/core/parser.py
+++ b/src/hosts/core/parser.py
@@ -13,56 +13,58 @@ from .models import HostEntry, HostsFile
 class HostsParser:
     """
     Parser for reading and writing hosts files.
-    
+
     Handles the complete hosts file format including comments,
     blank lines, and both active and inactive entries.
     """
-    
+
     def __init__(self, file_path: str = "/etc/hosts"):
         """
         Initialize the parser with a hosts file path.
-        
+
         Args:
             file_path: Path to the hosts file (default: /etc/hosts)
         """
         self.file_path = Path(file_path)
-    
+
     def parse(self) -> HostsFile:
         """
         Parse the hosts file into a HostsFile object.
-        
+
         Returns:
             HostsFile object containing all parsed entries and comments
-            
+
         Raises:
             FileNotFoundError: If the hosts file doesn't exist
             PermissionError: If the file cannot be read
         """
         if not self.file_path.exists():
             raise FileNotFoundError(f"Hosts file not found: {self.file_path}")
-        
+
         try:
-            with open(self.file_path, 'r', encoding='utf-8') as f:
+            with open(self.file_path, "r", encoding="utf-8") as f:
                 lines = f.readlines()
         except PermissionError:
-            raise PermissionError(f"Permission denied reading hosts file: {self.file_path}")
-        
+            raise PermissionError(
+                f"Permission denied reading hosts file: {self.file_path}"
+            )
+
         hosts_file = HostsFile()
         entries_started = False
-        
+
         for line_num, line in enumerate(lines, 1):
             stripped_line = line.strip()
-            
+
             # Try to parse as a host entry
             entry = HostEntry.from_hosts_line(stripped_line)
-            
+
             if entry is not None:
                 # This is a valid host entry
                 hosts_file.entries.append(entry)
                 entries_started = True
             elif stripped_line and not entries_started:
                 # This is a comment before any entries (header)
-                if stripped_line.startswith('#'):
+                if stripped_line.startswith("#"):
                     comment_text = stripped_line[1:].strip()
                     hosts_file.header_comments.append(comment_text)
                 else:
@@ -70,31 +72,31 @@ class HostsParser:
                     hosts_file.header_comments.append(stripped_line)
             elif stripped_line and entries_started:
                 # This is a comment after entries have started
-                if stripped_line.startswith('#'):
+                if stripped_line.startswith("#"):
                     comment_text = stripped_line[1:].strip()
                     hosts_file.footer_comments.append(comment_text)
                 else:
                     # Non-comment, non-entry line after entries
                     hosts_file.footer_comments.append(stripped_line)
             # Empty lines are ignored but structure is preserved in serialization
-        
+
         return hosts_file
-    
+
     def serialize(self, hosts_file: HostsFile) -> str:
         """
         Convert a HostsFile object back to hosts file format with proper column alignment.
-        
+
         Args:
             hosts_file: HostsFile object to serialize
-            
+
         Returns:
             String representation of the hosts file with tab-aligned columns
         """
         lines = []
-        
+
         # Ensure header has management line
         header_comments = self._ensure_management_header(hosts_file.header_comments)
-        
+
         # Add header comments
         if header_comments:
             for comment in header_comments:
@@ -102,14 +104,14 @@ class HostsParser:
                     lines.append(f"# {comment}")
                 else:
                     lines.append("#")
-        
+
         # Calculate column widths for proper alignment
         ip_width, hostname_width = self._calculate_column_widths(hosts_file.entries)
-        
+
         # Add host entries with proper column alignment
         for entry in hosts_file.entries:
             lines.append(entry.to_hosts_line(ip_width, hostname_width))
-        
+
         # Add footer comments
         if hosts_file.footer_comments:
             lines.append("")  # Blank line before footer
@@ -118,64 +120,60 @@ class HostsParser:
                     lines.append(f"# {comment}")
                 else:
                     lines.append("#")
-        
+
         return "\n".join(lines) + "\n"
-    
+
     def _ensure_management_header(self, header_comments: list) -> list:
         """
         Ensure the header contains the management line with proper formatting.
-        
+
         Args:
             header_comments: List of existing header comments
-            
+
         Returns:
             List of header comments with management line added if needed
         """
         management_line = "Managed by hosts - https://git.s1q.dev/phg/hosts"
-        
+
         # Check if management line already exists
         for comment in header_comments:
             if "git.s1q.dev/phg/hosts" in comment:
                 return header_comments
-        
+
         # If no header exists, create default header
         if not header_comments:
-            return [
-                "#",
-                "Host Database",
-                "",
-                management_line,
-                "#"
-            ]
-        
+            return ["#", "Host Database", "", management_line, "#"]
+
         # Check for enclosing comment patterns
         enclosing_pattern = self._detect_enclosing_pattern(header_comments)
-        
+
         if enclosing_pattern:
             # Insert management line within the enclosing pattern
-            return self._insert_in_enclosing_pattern(header_comments, management_line, enclosing_pattern)
+            return self._insert_in_enclosing_pattern(
+                header_comments, management_line, enclosing_pattern
+            )
         else:
             # No enclosing pattern, append management line
             result = header_comments.copy()
             result.append(management_line)
             return result
-    
+
     def _detect_enclosing_pattern(self, header_comments: list) -> dict | None:
         """
         Detect if header has enclosing comment patterns like ###, # #, etc.
-        
+
         Args:
             header_comments: List of header comments
-            
+
         Returns:
             Dictionary with pattern info or None if no pattern detected
         """
         if len(header_comments) < 2:
             return None
-        
+
         # Look for matching patterns at start and end, ignoring management line if present
         first_line = header_comments[0].strip()
-        
+
         # Find the last line that could be a closing pattern (not the management line)
         last_pattern_index = -1
         for i in range(len(header_comments) - 1, -1, -1):
@@ -183,58 +181,64 @@ class HostsParser:
             if "git.s1q.dev/phg/hosts" not in line:
                 last_pattern_index = i
                 break
-        
+
         if last_pattern_index <= 0:
             return None
-            
+
         last_line = header_comments[last_pattern_index].strip()
-        
+
         # Check for ### pattern
         if first_line == "###" and last_line == "###":
             return {
-                'type': 'triple_hash',
-                'start_index': 0,
-                'end_index': last_pattern_index,
-                'pattern': '###'
+                "type": "triple_hash",
+                "start_index": 0,
+                "end_index": last_pattern_index,
+                "pattern": "###",
             }
-        
+
         # Check for # # pattern
         if first_line == "#" and last_line == "#":
             return {
-                'type': 'single_hash',
-                'start_index': 0,
-                'end_index': last_pattern_index,
-                'pattern': '#'
+                "type": "single_hash",
+                "start_index": 0,
+                "end_index": last_pattern_index,
+                "pattern": "#",
             }
-        
+
         # Check for other repeating patterns (like ####, #####, etc.)
-        if len(first_line) > 1 and first_line == last_line and all(c == '#' for c in first_line):
+        if (
+            len(first_line) > 1
+            and first_line == last_line
+            and all(c == "#" for c in first_line)
+        ):
             return {
-                'type': 'repeating_hash',
-                'start_index': 0,
-                'end_index': last_pattern_index,
-                'pattern': first_line
+                "type": "repeating_hash",
+                "start_index": 0,
+                "end_index": last_pattern_index,
+                "pattern": first_line,
             }
-        
+
         return None
-    
-    def _insert_in_enclosing_pattern(self, header_comments: list, management_line: str, pattern_info: dict) -> list:
+
+    def _insert_in_enclosing_pattern(
+        self, header_comments: list, management_line: str, pattern_info: dict
+    ) -> list:
         """
         Insert management line within an enclosing comment pattern.
-        
+
         Args:
             header_comments: List of header comments
             management_line: Management line to insert
             pattern_info: Information about the enclosing pattern
-            
+
         Returns:
             Updated list of header comments
         """
         result = header_comments.copy()
-        
+
         # Find the best insertion point (before the closing pattern)
-        insert_index = pattern_info['end_index']
-        
+        insert_index = pattern_info["end_index"]
+
         # Look for an empty line before the closing pattern to insert after it
         # Otherwise, insert right before the closing pattern
         if insert_index > 1 and header_comments[insert_index - 1].strip() == "":
@@ -244,22 +248,22 @@ class HostsParser:
             # Insert empty line and management line before closing pattern
             result.insert(insert_index, "")
             result.insert(insert_index + 1, management_line)
-        
+
         return result
-    
+
     def _calculate_column_widths(self, entries: list) -> tuple[int, int]:
         """
         Calculate the maximum width needed for IP and hostname columns.
-        
+
         Args:
             entries: List of HostEntry objects
-            
+
         Returns:
             Tuple of (ip_width, hostname_width)
         """
         max_ip_width = 0
         max_hostname_width = 0
-        
+
         for entry in entries:
             # Calculate IP column width (including comment prefix for inactive entries)
             ip_part = ""
@@ -267,62 +271,63 @@ class HostsParser:
                 ip_part = "# "
             ip_part += entry.ip_address
             max_ip_width = max(max_ip_width, len(ip_part))
-            
+
             # Calculate canonical hostname width
             if entry.hostnames:
                 canonical_hostname = entry.hostnames[0]
                 max_hostname_width = max(max_hostname_width, len(canonical_hostname))
-        
+
         # Round up to next tab stop (8-character boundaries) for better alignment
         tab_width = 8
         ip_width = ((max_ip_width + tab_width - 1) // tab_width) * tab_width
         hostname_width = ((max_hostname_width + tab_width - 1) // tab_width) * tab_width
-        
+
         return ip_width, hostname_width
-    
+
     def write(self, hosts_file: HostsFile, backup: bool = True) -> None:
         """
         Write a HostsFile object to the hosts file.
-        
+
         Args:
             hosts_file: HostsFile object to write
             backup: Whether to create a backup before writing
-            
+
         Raises:
             PermissionError: If the file cannot be written
             OSError: If there's an error during file operations
         """
         # Create backup if requested
         if backup and self.file_path.exists():
-            backup_path = self.file_path.with_suffix('.bak')
+            backup_path = self.file_path.with_suffix(".bak")
             try:
                 import shutil
+
                 shutil.copy2(self.file_path, backup_path)
             except Exception as e:
                 raise OSError(f"Failed to create backup: {e}")
-        
+
         # Serialize the hosts file
         content = self.serialize(hosts_file)
-        
+
         # Write atomically using a temporary file
-        temp_path = self.file_path.with_suffix('.tmp')
+        temp_path = self.file_path.with_suffix(".tmp")
         try:
-            with open(temp_path, 'w', encoding='utf-8') as f:
+            with open(temp_path, "w", encoding="utf-8") as f:
                 f.write(content)
-            
+
             # Atomic move
             temp_path.replace(self.file_path)
-            
+
         except Exception as e:
             # Clean up temp file if it exists
             if temp_path.exists():
                 temp_path.unlink()
             raise OSError(f"Failed to write hosts file: {e}")
-    
+
     def validate_write_permissions(self) -> bool:
         """
         Check if we have write permissions to the hosts file.
-        
+
         Returns:
             True if we can write to the file, False otherwise
         """
@@ -335,51 +340,55 @@ class HostsParser:
                 return os.access(self.file_path.parent, os.W_OK)
         except Exception:
             return False
-    
+
     def get_file_info(self) -> dict:
         """
         Get information about the hosts file.
-        
+
         Returns:
             Dictionary with file information
         """
         info = {
-            'path': str(self.file_path),
-            'exists': self.file_path.exists(),
-            'readable': False,
-            'writable': False,
-            'size': 0,
-            'modified': None
+            "path": str(self.file_path),
+            "exists": self.file_path.exists(),
+            "readable": False,
+            "writable": False,
+            "size": 0,
+            "modified": None,
         }
-        
-        if info['exists']:
+
+        if info["exists"]:
             try:
-                info['readable'] = os.access(self.file_path, os.R_OK)
-                info['writable'] = os.access(self.file_path, os.W_OK)
+                info["readable"] = os.access(self.file_path, os.R_OK)
+                info["writable"] = os.access(self.file_path, os.W_OK)
                 stat = self.file_path.stat()
-                info['size'] = stat.st_size
-                info['modified'] = stat.st_mtime
+                info["size"] = stat.st_size
+                info["modified"] = stat.st_mtime
             except Exception:
                 pass
-        
+
         return info
 
 
 class HostsParserError(Exception):
     """Base exception for hosts parser errors."""
+
     pass
 
 
 class HostsFileNotFoundError(HostsParserError):
     """Raised when the hosts file is not found."""
+
     pass
 
 
 class HostsPermissionError(HostsParserError):
     """Raised when there are permission issues with the hosts file."""
+
     pass
 
 
 class HostsValidationError(HostsParserError):
     """Raised when hosts file content is invalid."""
+
     pass
diff --git a/src/hosts/tui/app.py b/src/hosts/tui/app.py
index a1009d8..1c0fd27 100644
--- a/src/hosts/tui/app.py
+++ b/src/hosts/tui/app.py
@@ -15,6 +15,7 @@ from ..core.models import HostsFile
 from ..core.config import Config
 from ..core.manager import HostsManager
 from .config_modal import ConfigModal
+from .password_modal import PasswordModal
 from .styles import HOSTS_MANAGER_CSS
 from .keybindings import HOSTS_MANAGER_BINDINGS
 from .table_handler import TableHandler
@@ -46,18 +47,18 @@ class HostsManagerApp(App):
         super().__init__()
         self.title = "/etc/hosts Manager"
         self.sub_title = ""  # Will be set by update_status
-        
+
         # Initialize core components
         self.parser = HostsParser()
         self.config = Config()
         self.manager = HostsManager()
-        
+
         # Initialize handlers
         self.table_handler = TableHandler(self)
         self.details_handler = DetailsHandler(self)
         self.edit_handler = EditHandler(self)
         self.navigation_handler = NavigationHandler(self)
-        
+
         # State for edit mode
         self.original_entry_values = None
 
@@ -75,7 +76,12 @@ class HostsManagerApp(App):
             # Right pane - entry details or edit form
             with Vertical(classes="right-pane") as right_pane:
                 right_pane.border_title = "Entry Details"
-                yield DataTable(id="entry-details-table", show_header=False, show_cursor=False, disabled=True)
+                yield DataTable(
+                    id="entry-details-table",
+                    show_header=False,
+                    show_cursor=False,
+                    disabled=True,
+                )
 
                 # Edit form (initially hidden)
                 with Vertical(id="entry-edit-form", classes="hidden"):
@@ -84,7 +90,9 @@ class HostsManagerApp(App):
                     yield Label("Hostnames (comma-separated):")
                     yield Input(placeholder="Enter hostnames", id="hostname-input")
                     yield Label("Comment:")
-                    yield Input(placeholder="Enter comment (optional)", id="comment-input")
+                    yield Input(
+                        placeholder="Enter comment (optional)", id="comment-input"
+                    )
                     yield Checkbox("Active", id="active-checkbox")
 
         # Status bar for error/temporary messages (overlay, doesn't affect layout)
@@ -99,9 +107,8 @@ class HostsManagerApp(App):
         try:
             # Remember the currently selected entry before reload
             previous_entry = None
-            if (
+            if self.hosts_file.entries and self.selected_entry_index < len(
                 self.hosts_file.entries
-                and self.selected_entry_index < len(self.hosts_file.entries)
             ):
                 previous_entry = self.hosts_file.entries[self.selected_entry_index]
 
@@ -121,17 +128,17 @@ class HostsManagerApp(App):
                 status_bar = self.query_one("#status-bar", Static)
                 status_bar.update(message)
                 status_bar.remove_class("hidden")
-                
+
                 if message.startswith("❌"):
                     # Auto-clear error message after 5 seconds
                     self.set_timer(5.0, lambda: self._clear_status_message())
                 else:
-                    # Auto-clear regular message after 3 seconds  
+                    # Auto-clear regular message after 3 seconds
                     self.set_timer(3.0, lambda: self._clear_status_message())
-            except:
+            except Exception:
                 # Fallback if status bar not found (during initialization)
                 pass
-        
+
         # Always update the header subtitle with current status
         mode = "Edit mode" if self.edit_mode else "Read-only mode"
         entry_count = len(self.hosts_file.entries)
@@ -146,7 +153,7 @@ class HostsManagerApp(App):
             status_bar = self.query_one("#status-bar", Static)
             status_bar.update("")
             status_bar.add_class("hidden")
-        except:
+        except Exception:
             pass
 
     # Event handlers
@@ -154,8 +161,8 @@ class HostsManagerApp(App):
         """Handle row highlighting (cursor movement) in the DataTable."""
         if event.data_table.id == "entries-table":
             # Convert display index to actual index
-            self.selected_entry_index = self.table_handler.display_index_to_actual_index(
-                event.cursor_row
+            self.selected_entry_index = (
+                self.table_handler.display_index_to_actual_index(event.cursor_row)
             )
             self.details_handler.update_entry_details()
 
@@ -163,8 +170,8 @@ class HostsManagerApp(App):
         """Handle row selection in the DataTable."""
         if event.data_table.id == "entries-table":
             # Convert display index to actual index
-            self.selected_entry_index = self.table_handler.display_index_to_actual_index(
-                event.cursor_row
+            self.selected_entry_index = (
+                self.table_handler.display_index_to_actual_index(event.cursor_row)
             )
             self.details_handler.update_entry_details()
 
@@ -213,6 +220,7 @@ class HostsManagerApp(App):
 
     def action_config(self) -> None:
         """Show configuration modal."""
+
         def handle_config_result(config_changed: bool) -> None:
             if config_changed:
                 # Reload the table to apply new filtering
@@ -245,15 +253,42 @@ class HostsManagerApp(App):
             else:
                 self.update_status(f"Error exiting edit mode: {message}")
         else:
-            # Enter edit mode
+            # Enter edit mode - first try without password
             success, message = self.manager.enter_edit_mode()
             if success:
                 self.edit_mode = True
                 self.sub_title = "Edit mode"
                 self.update_status(message)
+            elif "Password required" in message:
+                # Show password modal
+                self._request_sudo_password()
             else:
                 self.update_status(f"Error entering edit mode: {message}")
 
+    def _request_sudo_password(self) -> None:
+        """Show password modal and attempt sudo authentication."""
+
+        def handle_password(password: str) -> None:
+            if password is None:
+                # User cancelled
+                self.update_status("Edit mode cancelled")
+                return
+
+            # Try to enter edit mode with password
+            success, message = self.manager.enter_edit_mode(password)
+            if success:
+                self.edit_mode = True
+                self.sub_title = "Edit mode"
+                self.update_status(message)
+            elif "Incorrect password" in message:
+                # Show error and try again
+                self.update_status("❌ Incorrect password. Please try again.")
+                self.set_timer(2.0, lambda: self._request_sudo_password())
+            else:
+                self.update_status(f"❌ Error entering edit mode: {message}")
+
+        self.push_screen(PasswordModal(), handle_password)
+
     def action_edit_entry(self) -> None:
         """Enter edit mode for the selected entry."""
         if not self.edit_mode:
diff --git a/src/hosts/tui/config_modal.py b/src/hosts/tui/config_modal.py
index d7f2245..618853c 100644
--- a/src/hosts/tui/config_modal.py
+++ b/src/hosts/tui/config_modal.py
@@ -16,10 +16,10 @@ from ..core.config import Config
 class ConfigModal(ModalScreen):
     """
     Modal screen for application configuration.
-    
+
     Provides a floating window with configuration options.
     """
-    
+
     CSS = """
     ConfigModal {
         align: center middle;
@@ -58,51 +58,58 @@ class ConfigModal(ModalScreen):
         min-width: 10;
     }
     """
-    
+
     BINDINGS = [
         Binding("escape", "cancel", "Cancel"),
         Binding("enter", "save", "Save"),
     ]
-    
+
     def __init__(self, config: Config):
         super().__init__()
         self.config = config
-    
+
     def compose(self) -> ComposeResult:
         """Create the configuration modal layout."""
         with Vertical(classes="config-container"):
             yield Static("Configuration", classes="config-title")
-            
+
             with Vertical(classes="config-section"):
                 yield Label("Display Options:")
                 yield Checkbox(
                     "Show default system entries (localhost, broadcasthost)",
                     value=self.config.should_show_default_entries(),
                     id="show-defaults-checkbox",
-                    classes="config-option"
+                    classes="config-option",
                 )
-            
+
             with Horizontal(classes="button-row"):
-                yield Button("Save", variant="primary", id="save-button", classes="config-button")
-                yield Button("Cancel", variant="default", id="cancel-button", classes="config-button")
-    
+                yield Button(
+                    "Save", variant="primary", id="save-button", classes="config-button"
+                )
+                yield Button(
+                    "Cancel",
+                    variant="default",
+                    id="cancel-button",
+                    classes="config-button",
+                )
+
     def on_button_pressed(self, event: Button.Pressed) -> None:
         """Handle button presses."""
         if event.button.id == "save-button":
             self.action_save()
         elif event.button.id == "cancel-button":
             self.action_cancel()
-    
+
     def action_save(self) -> None:
         """Save configuration and close modal."""
         # Get checkbox state
         checkbox = self.query_one("#show-defaults-checkbox", Checkbox)
         self.config.set("show_default_entries", checkbox.value)
         self.config.save()
-        
+
         # Close modal and signal that config was changed
         self.dismiss(True)
-    
+
     def action_cancel(self) -> None:
         """Cancel configuration changes and close modal."""
         self.dismiss(False)
diff --git a/src/hosts/tui/details_handler.py b/src/hosts/tui/details_handler.py
index 762ce81..c3c4102 100644
--- a/src/hosts/tui/details_handler.py
+++ b/src/hosts/tui/details_handler.py
@@ -5,16 +5,16 @@ This module handles the display and updating of entry details
 and edit forms in the right pane.
 """
 
-from textual.widgets import Static, Input, Checkbox, DataTable
+from textual.widgets import Input, Checkbox, DataTable
 
 
 class DetailsHandler:
     """Handles all details pane operations for the hosts manager."""
-    
+
     def __init__(self, app):
         """Initialize the details handler with reference to the main app."""
         self.app = app
-    
+
     def update_entry_details(self) -> None:
         """Update the right pane with selected entry details."""
         if self.app.entry_edit_mode:
@@ -82,7 +82,9 @@ class DetailsHandler:
         details_table.add_row("IP Address", entry.ip_address, key="ip")
         details_table.add_row("Hostnames", ", ".join(entry.hostnames), key="hostnames")
         details_table.add_row("Comment", entry.comment or "", key="comment")
-        details_table.add_row("Active", "Yes" if entry.is_active else "No", key="active")
+        details_table.add_row(
+            "Active", "Yes" if entry.is_active else "No", key="active"
+        )
 
         # Add DNS name if present (not in edit form but good to show)
         if entry.dns_name:
diff --git a/src/hosts/tui/edit_handler.py b/src/hosts/tui/edit_handler.py
index 4bf0d11..ce6b514 100644
--- a/src/hosts/tui/edit_handler.py
+++ b/src/hosts/tui/edit_handler.py
@@ -13,11 +13,11 @@ from .save_confirmation_modal import SaveConfirmationModal
 
 class EditHandler:
     """Handles all edit mode operations for the hosts manager."""
-    
+
     def __init__(self, app):
         """Initialize the edit handler with reference to the main app."""
         self.app = app
-    
+
     def has_entry_changes(self) -> bool:
         """Check if the current entry has been modified from its original values."""
         if not self.app.original_entry_values or not self.app.entry_edit_mode:
@@ -203,7 +203,7 @@ class EditHandler:
 
     def handle_entry_edit_key_event(self, event) -> bool:
         """Handle key events for entry edit mode navigation.
-        
+
         Returns True if the event was handled, False otherwise.
         """
         # Only handle custom tab navigation if in entry edit mode AND no modal is open
@@ -218,5 +218,5 @@ class EditHandler:
                 event.prevent_default()
                 self.navigate_to_prev_field()
                 return True
-        
+
         return False
diff --git a/src/hosts/tui/navigation_handler.py b/src/hosts/tui/navigation_handler.py
index 0e7c067..733b895 100644
--- a/src/hosts/tui/navigation_handler.py
+++ b/src/hosts/tui/navigation_handler.py
@@ -10,11 +10,11 @@ from textual.widgets import DataTable
 
 class NavigationHandler:
     """Handles all navigation and action operations for the hosts manager."""
-    
+
     def __init__(self, app):
         """Initialize the navigation handler with reference to the main app."""
         self.app = app
-    
+
     def toggle_entry(self) -> None:
         """Toggle the active state of the selected entry."""
         if not self.app.edit_mode:
@@ -35,11 +35,18 @@ class NavigationHandler:
         )
         if success:
             # Auto-save the changes immediately
-            save_success, save_message = self.app.manager.save_hosts_file(self.app.hosts_file)
+            save_success, save_message = self.app.manager.save_hosts_file(
+                self.app.hosts_file
+            )
             if save_success:
                 self.app.table_handler.populate_entries_table()
                 # Restore cursor position to the same entry
-                self.app.set_timer(0.1, lambda: self.app.table_handler.restore_cursor_position(current_entry))
+                self.app.set_timer(
+                    0.1,
+                    lambda: self.app.table_handler.restore_cursor_position(
+                        current_entry
+                    ),
+                )
                 self.app.details_handler.update_entry_details()
                 self.app.update_status(f"{message} - Changes saved automatically")
             else:
@@ -64,7 +71,9 @@ class NavigationHandler:
         )
         if success:
             # Auto-save the changes immediately
-            save_success, save_message = self.app.manager.save_hosts_file(self.app.hosts_file)
+            save_success, save_message = self.app.manager.save_hosts_file(
+                self.app.hosts_file
+            )
             if save_success:
                 # Update the selection index to follow the moved entry
                 if self.app.selected_entry_index > 0:
@@ -101,7 +110,9 @@ class NavigationHandler:
         )
         if success:
             # Auto-save the changes immediately
-            save_success, save_message = self.app.manager.save_hosts_file(self.app.hosts_file)
+            save_success, save_message = self.app.manager.save_hosts_file(
+                self.app.hosts_file
+            )
             if save_success:
                 # Update the selection index to follow the moved entry
                 if self.app.selected_entry_index < len(self.app.hosts_file.entries) - 1:
@@ -145,5 +156,5 @@ class NavigationHandler:
         # If in edit mode, exit it first
         if self.app.edit_mode:
             self.app.manager.exit_edit_mode()
-        
+
         self.app.exit()
diff --git a/src/hosts/tui/password_modal.py b/src/hosts/tui/password_modal.py
new file mode 100644
index 0000000..9467e66
--- /dev/null
+++ b/src/hosts/tui/password_modal.py
@@ -0,0 +1,152 @@
+"""
+Password input modal window for sudo authentication.
+
+This module provides a secure password input modal for sudo operations.
+"""
+
+from textual.app import ComposeResult
+from textual.containers import Vertical, Horizontal
+from textual.widgets import Static, Button, Input
+from textual.screen import ModalScreen
+from textual.binding import Binding
+
+
+class PasswordModal(ModalScreen):
+    """
+    Modal screen for secure password input.
+
+    Provides a floating window for entering sudo password with proper masking.
+    """
+
+    CSS = """
+    PasswordModal {
+        align: center middle;
+    }
+    
+    .password-container {
+        width: 60;
+        height: 12;
+        background: $surface;
+        border: thick $primary;
+        padding: 1;
+    }
+    
+    .password-title {
+        text-align: center;
+        text-style: bold;
+        color: $primary;
+        margin-bottom: 1;
+    }
+    
+    .password-message {
+        text-align: center;
+        color: $text;
+        margin-bottom: 1;
+    }
+    
+    .password-input {
+        margin: 1 0;
+    }
+    
+    .button-row {
+        margin-top: 1;
+        align: center middle;
+    }
+    
+    .password-button {
+        margin: 0 1;
+        min-width: 10;
+    }
+    
+    .error-message {
+        color: $error;
+        text-align: center;
+        margin: 1 0;
+    }
+    """
+
+    BINDINGS = [
+        Binding("escape", "cancel", "Cancel"),
+        Binding("enter", "submit", "Submit"),
+    ]
+
+    def __init__(self, message: str = "Enter your password for sudo access:"):
+        super().__init__()
+        self.message = message
+        self.error_message = ""
+
+    def compose(self) -> ComposeResult:
+        """Create the password modal layout."""
+        with Vertical(classes="password-container"):
+            yield Static("Sudo Authentication", classes="password-title")
+            yield Static(self.message, classes="password-message")
+
+            yield Input(
+                placeholder="Password",
+                password=True,
+                id="password-input",
+                classes="password-input",
+            )
+
+            # Error message placeholder (initially empty)
+            yield Static("", id="error-message", classes="error-message")
+
+            with Horizontal(classes="button-row"):
+                yield Button(
+                    "OK", variant="primary", id="ok-button", classes="password-button"
+                )
+                yield Button(
+                    "Cancel",
+                    variant="default",
+                    id="cancel-button",
+                    classes="password-button",
+                )
+
+    def on_mount(self) -> None:
+        """Focus the password input when modal opens."""
+        password_input = self.query_one("#password-input", Input)
+        password_input.focus()
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        """Handle button presses."""
+        if event.button.id == "ok-button":
+            self.action_submit()
+        elif event.button.id == "cancel-button":
+            self.action_cancel()
+    
+    def on_input_submitted(self, event: Input.Submitted) -> None:
+        """Handle Enter key in password input field."""
+        if event.input.id == "password-input":
+            self.action_submit()
+
+    def action_submit(self) -> None:
+        """Submit the password and close modal."""
+        password_input = self.query_one("#password-input", Input)
+        password = password_input.value
+
+        if not password:
+            self.show_error("Password cannot be empty")
+            return
+
+        # Clear any previous error
+        self.clear_error()
+
+        # Return the password
+        self.dismiss(password)
+
+    def action_cancel(self) -> None:
+        """Cancel password input and close modal."""
+        self.dismiss(None)
+
+    def show_error(self, message: str) -> None:
+        """Show an error message in the modal."""
+        error_static = self.query_one("#error-message", Static)
+        error_static.update(message)
+        # Keep focus on password input
+        password_input = self.query_one("#password-input", Input)
+        password_input.focus()
+
+    def clear_error(self) -> None:
+        """Clear the error message."""
+        error_static = self.query_one("#error-message", Static)
+        error_static.update("")
diff --git a/src/hosts/tui/table_handler.py b/src/hosts/tui/table_handler.py
index 260d670..1d94362 100644
--- a/src/hosts/tui/table_handler.py
+++ b/src/hosts/tui/table_handler.py
@@ -11,11 +11,11 @@ from textual.widgets import DataTable
 
 class TableHandler:
     """Handles all data table operations for the hosts manager."""
-    
+
     def __init__(self, app):
         """Initialize the table handler with reference to the main app."""
         self.app = app
-    
+
     def get_visible_entries(self) -> list:
         """Get the list of entries that are visible in the table (after filtering)."""
         show_defaults = self.app.config.should_show_default_entries()
@@ -160,7 +160,9 @@ class TableHandler:
 
         # Update the DataTable cursor position using display index
         table = self.app.query_one("#entries-table", DataTable)
-        display_index = self.actual_index_to_display_index(self.app.selected_entry_index)
+        display_index = self.actual_index_to_display_index(
+            self.app.selected_entry_index
+        )
         if table.row_count > 0 and display_index < table.row_count:
             # Move cursor to the selected row
             table.move_cursor(row=display_index)
@@ -180,13 +182,14 @@ class TableHandler:
 
         # Remember the currently selected entry
         current_entry = None
-        if self.app.hosts_file.entries and self.app.selected_entry_index < len(self.app.hosts_file.entries):
+        if self.app.hosts_file.entries and self.app.selected_entry_index < len(
+            self.app.hosts_file.entries
+        ):
             current_entry = self.app.hosts_file.entries[self.app.selected_entry_index]
 
         # Sort the entries
         self.app.hosts_file.entries.sort(
-            key=lambda entry: entry.ip_address,
-            reverse=not self.app.sort_ascending
+            key=lambda entry: entry.ip_address, reverse=not self.app.sort_ascending
         )
 
         # Refresh the table and restore cursor position
@@ -205,13 +208,15 @@ class TableHandler:
 
         # Remember the currently selected entry
         current_entry = None
-        if self.app.hosts_file.entries and self.app.selected_entry_index < len(self.app.hosts_file.entries):
+        if self.app.hosts_file.entries and self.app.selected_entry_index < len(
+            self.app.hosts_file.entries
+        ):
             current_entry = self.app.hosts_file.entries[self.app.selected_entry_index]
 
         # Sort the entries
         self.app.hosts_file.entries.sort(
             key=lambda entry: entry.hostnames[0].lower() if entry.hostnames else "",
-            reverse=not self.app.sort_ascending
+            reverse=not self.app.sort_ascending,
         )
 
         # Refresh the table and restore cursor position
diff --git a/tests/test_config.py b/tests/test_config.py
index 4adc7ee..cf6af9d 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -15,276 +15,291 @@ from hosts.core.config import Config
 
 class TestConfig:
     """Test cases for the Config class."""
-    
+
     def test_config_initialization(self):
         """Test basic config initialization with defaults."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             # Check default settings
             assert config.get("show_default_entries") is False
             assert len(config.get("default_entries", [])) == 3
             assert config.get("window_settings", {}).get("last_sort_column") == ""
             assert config.get("window_settings", {}).get("last_sort_ascending") is True
-    
+
     def test_default_settings_structure(self):
         """Test that default settings have the expected structure."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             default_entries = config.get("default_entries", [])
             assert len(default_entries) == 3
-            
+
             # Check localhost entries
-            localhost_entries = [e for e in default_entries if e["hostname"] == "localhost"]
+            localhost_entries = [
+                e for e in default_entries if e["hostname"] == "localhost"
+            ]
             assert len(localhost_entries) == 2  # IPv4 and IPv6
-            
+
             # Check broadcasthost entry
-            broadcast_entries = [e for e in default_entries if e["hostname"] == "broadcasthost"]
+            broadcast_entries = [
+                e for e in default_entries if e["hostname"] == "broadcasthost"
+            ]
             assert len(broadcast_entries) == 1
             assert broadcast_entries[0]["ip"] == "255.255.255.255"
-    
+
     def test_config_paths(self):
         """Test that config paths are set correctly."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             expected_dir = Path.home() / ".config" / "hosts-manager"
             expected_file = expected_dir / "config.json"
-            
+
             assert config.config_dir == expected_dir
             assert config.config_file == expected_file
-    
+
     def test_get_existing_key(self):
         """Test getting an existing configuration key."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             result = config.get("show_default_entries")
             assert result is False
-    
+
     def test_get_nonexistent_key_with_default(self):
         """Test getting a nonexistent key with default value."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             result = config.get("nonexistent_key", "default_value")
             assert result == "default_value"
-    
+
     def test_get_nonexistent_key_without_default(self):
         """Test getting a nonexistent key without default value."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             result = config.get("nonexistent_key")
             assert result is None
-    
+
     def test_set_configuration_value(self):
         """Test setting a configuration value."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             config.set("test_key", "test_value")
             assert config.get("test_key") == "test_value"
-    
+
     def test_set_overwrites_existing_value(self):
         """Test that setting overwrites existing values."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             # Set initial value
             config.set("show_default_entries", True)
             assert config.get("show_default_entries") is True
-            
+
             # Overwrite with new value
             config.set("show_default_entries", False)
             assert config.get("show_default_entries") is False
-    
+
     def test_is_default_entry_true(self):
         """Test identifying default entries correctly."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             # Test localhost IPv4
             assert config.is_default_entry("127.0.0.1", "localhost") is True
-            
+
             # Test localhost IPv6
             assert config.is_default_entry("::1", "localhost") is True
-            
+
             # Test broadcasthost
             assert config.is_default_entry("255.255.255.255", "broadcasthost") is True
-    
+
     def test_is_default_entry_false(self):
         """Test that non-default entries are not identified as default."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             # Test custom entries
             assert config.is_default_entry("192.168.1.1", "router") is False
             assert config.is_default_entry("10.0.0.1", "test.local") is False
             assert config.is_default_entry("127.0.0.1", "custom") is False
-    
+
     def test_should_show_default_entries_default(self):
         """Test default value for show_default_entries."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
-            
+
             assert config.should_show_default_entries() is False
-    
+
     def test_should_show_default_entries_configured(self):
         """Test configured value for show_default_entries."""
-        with patch.object(Config, 'load'):
+        with patch.object(Config, "load"):
             config = Config()
             config.set("show_default_entries", True)
-            
+
             assert config.should_show_default_entries() is True
-    
+
     def test_toggle_show_default_entries(self):
         """Test toggling the show_default_entries setting."""
-        with patch.object(Config, 'load'), patch.object(Config, 'save') as mock_save:
+        with patch.object(Config, "load"), patch.object(Config, "save") as mock_save:
             config = Config()
-            
+
             # Initial state should be False
             assert config.should_show_default_entries() is False
-            
+
             # Toggle to True
             config.toggle_show_default_entries()
             assert config.should_show_default_entries() is True
             mock_save.assert_called_once()
-            
+
             # Toggle back to False
             mock_save.reset_mock()
             config.toggle_show_default_entries()
             assert config.should_show_default_entries() is False
             mock_save.assert_called_once()
-    
+
     def test_load_nonexistent_file(self):
         """Test loading config when file doesn't exist."""
-        with patch('pathlib.Path.exists', return_value=False):
+        with patch("pathlib.Path.exists", return_value=False):
             config = Config()
-            
+
             # Should use defaults when file doesn't exist
             assert config.get("show_default_entries") is False
-    
+
     def test_load_existing_file(self):
         """Test loading config from existing file."""
-        test_config = {
-            "show_default_entries": True,
-            "custom_setting": "custom_value"
-        }
-        
-        with patch('pathlib.Path.exists', return_value=True), \
-             patch('builtins.open', mock_open(read_data=json.dumps(test_config))):
+        test_config = {"show_default_entries": True, "custom_setting": "custom_value"}
+
+        with (
+            patch("pathlib.Path.exists", return_value=True),
+            patch("builtins.open", mock_open(read_data=json.dumps(test_config))),
+        ):
             config = Config()
-            
+
             # Should load values from file
             assert config.get("show_default_entries") is True
             assert config.get("custom_setting") == "custom_value"
-            
+
             # Should still have defaults for missing keys
             assert len(config.get("default_entries", [])) == 3
-    
+
     def test_load_invalid_json(self):
         """Test loading config with invalid JSON falls back to defaults."""
-        with patch('pathlib.Path.exists', return_value=True), \
-             patch('builtins.open', mock_open(read_data="invalid json")):
+        with (
+            patch("pathlib.Path.exists", return_value=True),
+            patch("builtins.open", mock_open(read_data="invalid json")),
+        ):
             config = Config()
-            
+
             # Should use defaults when JSON is invalid
             assert config.get("show_default_entries") is False
-    
+
     def test_load_file_io_error(self):
         """Test loading config with file I/O error falls back to defaults."""
-        with patch('pathlib.Path.exists', return_value=True), \
-             patch('builtins.open', side_effect=IOError("File error")):
+        with (
+            patch("pathlib.Path.exists", return_value=True),
+            patch("builtins.open", side_effect=IOError("File error")),
+        ):
             config = Config()
-            
+
             # Should use defaults when file can't be read
             assert config.get("show_default_entries") is False
-    
+
     def test_save_creates_directory(self):
         """Test that save creates config directory if it doesn't exist."""
-        with patch.object(Config, 'load'), \
-             patch('pathlib.Path.mkdir') as mock_mkdir, \
-             patch('builtins.open', mock_open()) as mock_file:
+        with (
+            patch.object(Config, "load"),
+            patch("pathlib.Path.mkdir") as mock_mkdir,
+            patch("builtins.open", mock_open()) as mock_file,
+        ):
             config = Config()
             config.save()
-            
+
             # Should create directory with parents=True, exist_ok=True
             mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
             mock_file.assert_called_once()
-    
+
     def test_save_writes_json(self):
         """Test that save writes configuration as JSON."""
-        with patch.object(Config, 'load'), \
-             patch('pathlib.Path.mkdir'), \
-             patch('builtins.open', mock_open()) as mock_file:
+        with (
+            patch.object(Config, "load"),
+            patch("pathlib.Path.mkdir"),
+            patch("builtins.open", mock_open()) as mock_file,
+        ):
             config = Config()
             config.set("test_key", "test_value")
             config.save()
-            
+
             # Check that file was opened for writing
-            mock_file.assert_called_once_with(config.config_file, 'w')
-            
+            mock_file.assert_called_once_with(config.config_file, "w")
+
             # Check that JSON was written
             handle = mock_file()
-            written_data = ''.join(call.args[0] for call in handle.write.call_args_list)
-            
+            written_data = "".join(call.args[0] for call in handle.write.call_args_list)
+
             # Should be valid JSON containing our test data
             parsed_data = json.loads(written_data)
             assert parsed_data["test_key"] == "test_value"
-    
+
     def test_save_io_error_silent_fail(self):
         """Test that save silently fails on I/O error."""
-        with patch.object(Config, 'load'), \
-             patch('pathlib.Path.mkdir'), \
-             patch('builtins.open', side_effect=IOError("Write error")):
+        with (
+            patch.object(Config, "load"),
+            patch("pathlib.Path.mkdir"),
+            patch("builtins.open", side_effect=IOError("Write error")),
+        ):
             config = Config()
-            
+
             # Should not raise exception
             config.save()
-    
+
     def test_save_directory_creation_error_silent_fail(self):
         """Test that save silently fails on directory creation error."""
-        with patch.object(Config, 'load'), \
-             patch('pathlib.Path.mkdir', side_effect=OSError("Permission denied")):
+        with (
+            patch.object(Config, "load"),
+            patch("pathlib.Path.mkdir", side_effect=OSError("Permission denied")),
+        ):
             config = Config()
-            
+
             # Should not raise exception
             config.save()
-    
+
     def test_integration_load_save_roundtrip(self):
         """Test complete load/save cycle with temporary file."""
         with tempfile.TemporaryDirectory() as temp_dir:
             config_dir = Path(temp_dir) / "hosts-manager"
             config_file = config_dir / "config.json"
-            
-            with patch.object(Config, '__init__', lambda self: None):
+
+            with patch.object(Config, "__init__", lambda self: None):
                 config = Config()
                 config.config_dir = config_dir
                 config.config_file = config_file
                 config._settings = config._load_default_settings()
-                
+
                 # Modify some settings
                 config.set("show_default_entries", True)
                 config.set("custom_setting", "test_value")
-                
+
                 # Save configuration
                 config.save()
-                
+
                 # Verify file was created
                 assert config_file.exists()
-                
+
                 # Create new config instance and load
                 config2 = Config()
                 config2.config_dir = config_dir
                 config2.config_file = config_file
                 config2._settings = config2._load_default_settings()
                 config2.load()
-                
+
                 # Verify settings were loaded correctly
                 assert config2.get("show_default_entries") is True
                 assert config2.get("custom_setting") == "test_value"
-                
+
                 # Verify defaults are still present
                 assert len(config2.get("default_entries", [])) == 3
diff --git a/tests/test_config_modal.py b/tests/test_config_modal.py
index 52ab7d1..d9944e7 100644
--- a/tests/test_config_modal.py
+++ b/tests/test_config_modal.py
@@ -15,214 +15,217 @@ from hosts.tui.config_modal import ConfigModal
 
 class TestConfigModal:
     """Test cases for the ConfigModal class."""
-    
+
     def test_modal_initialization(self):
         """Test modal initialization with config."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = False
-        
+
         modal = ConfigModal(mock_config)
         assert modal.config == mock_config
-    
+
     def test_modal_compose_method_exists(self):
         """Test that modal has compose method."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = True
-        
+
         modal = ConfigModal(mock_config)
-        
+
         # Test that compose method exists and is callable
-        assert hasattr(modal, 'compose')
+        assert hasattr(modal, "compose")
         assert callable(modal.compose)
-    
+
     def test_action_save_updates_config(self):
         """Test that save action updates configuration."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = False
-        
+
         modal = ConfigModal(mock_config)
         modal.dismiss = Mock()
-        
+
         # Mock the checkbox query
         mock_checkbox = Mock()
         mock_checkbox.value = True
         modal.query_one = Mock(return_value=mock_checkbox)
-        
+
         # Trigger save action
         modal.action_save()
-        
+
         # Verify config was updated
         mock_config.set.assert_called_once_with("show_default_entries", True)
         mock_config.save.assert_called_once()
         modal.dismiss.assert_called_once_with(True)
-    
+
     def test_action_save_preserves_false_state(self):
         """Test that save action preserves False checkbox state."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = True
-        
+
         modal = ConfigModal(mock_config)
         modal.dismiss = Mock()
-        
+
         # Mock the checkbox query with False value
         mock_checkbox = Mock()
         mock_checkbox.value = False
         modal.query_one = Mock(return_value=mock_checkbox)
-        
+
         # Trigger save action
         modal.action_save()
-        
+
         # Verify the False value was saved
         mock_config.set.assert_called_once_with("show_default_entries", False)
         mock_config.save.assert_called_once()
         modal.dismiss.assert_called_once_with(True)
-    
+
     def test_action_cancel_no_config_changes(self):
         """Test that cancel action doesn't modify configuration."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = False
-        
+
         modal = ConfigModal(mock_config)
         modal.dismiss = Mock()
-        
+
         # Trigger cancel action
         modal.action_cancel()
-        
+
         # Verify config was NOT updated
         mock_config.set.assert_not_called()
         mock_config.save.assert_not_called()
         modal.dismiss.assert_called_once_with(False)
-    
+
     def test_save_button_pressed_event(self):
         """Test save button pressed event handling."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = False
-        
+
         modal = ConfigModal(mock_config)
         modal.action_save = Mock()
-        
+
         # Create mock save button
         save_button = Mock()
         save_button.id = "save-button"
         event = Button.Pressed(save_button)
-        
+
         modal.on_button_pressed(event)
-        
+
         modal.action_save.assert_called_once()
-    
+
     def test_cancel_button_pressed_event(self):
         """Test cancel button pressed event handling."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = False
-        
+
         modal = ConfigModal(mock_config)
         modal.action_cancel = Mock()
-        
+
         # Create mock cancel button
         cancel_button = Mock()
         cancel_button.id = "cancel-button"
         event = Button.Pressed(cancel_button)
-        
+
         modal.on_button_pressed(event)
-        
+
         modal.action_cancel.assert_called_once()
-    
+
     def test_unknown_button_pressed_ignored(self):
         """Test that unknown button presses are ignored."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = False
-        
+
         modal = ConfigModal(mock_config)
         modal.action_save = Mock()
         modal.action_cancel = Mock()
-        
+
         # Create a mock button with unknown ID
         unknown_button = Mock()
         unknown_button.id = "unknown-button"
         event = Button.Pressed(unknown_button)
-        
+
         # Should not raise exception
         modal.on_button_pressed(event)
-        
+
         # Should not trigger any actions
         modal.action_save.assert_not_called()
         modal.action_cancel.assert_not_called()
-    
+
     def test_modal_bindings_defined(self):
         """Test that modal has expected key bindings."""
         mock_config = Mock(spec=Config)
         modal = ConfigModal(mock_config)
-        
+
         # Check that bindings are defined
         assert len(modal.BINDINGS) == 2
-        
+
         # Check specific bindings
         binding_keys = [binding.key for binding in modal.BINDINGS]
         assert "escape" in binding_keys
         assert "enter" in binding_keys
-        
+
         binding_actions = [binding.action for binding in modal.BINDINGS]
         assert "cancel" in binding_actions
         assert "save" in binding_actions
-    
+
     def test_modal_css_defined(self):
         """Test that modal has CSS styling defined."""
         mock_config = Mock(spec=Config)
         modal = ConfigModal(mock_config)
-        
+
         # Check that CSS is defined
-        assert hasattr(modal, 'CSS')
+        assert hasattr(modal, "CSS")
         assert isinstance(modal.CSS, str)
         assert len(modal.CSS) > 0
-        
+
         # Check for key CSS classes
         assert "config-container" in modal.CSS
         assert "config-title" in modal.CSS
         assert "button-row" in modal.CSS
-    
+
     def test_config_method_called_during_initialization(self):
         """Test that config method is called during modal setup."""
         mock_config = Mock(spec=Config)
-        
+
         # Test with True
         mock_config.should_show_default_entries.return_value = True
         modal = ConfigModal(mock_config)
-        
+
         # Verify the config object is stored
         assert modal.config == mock_config
-        
+
         # Test with False
         mock_config.should_show_default_entries.return_value = False
         modal = ConfigModal(mock_config)
-        
+
         # Verify the config object is stored
         assert modal.config == mock_config
-    
+
     def test_compose_method_signature(self):
         """Test that compose method has the expected signature."""
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = False
-        
+
         modal = ConfigModal(mock_config)
-        
+
         # Test that compose method exists and has correct signature
         import inspect
+
         sig = inspect.signature(modal.compose)
         assert len(sig.parameters) == 0  # No parameters except self
-        
+
         # Test return type annotation if present
         if sig.return_annotation != inspect.Signature.empty:
             from textual.app import ComposeResult
+
             assert sig.return_annotation == ComposeResult
-    
+
     def test_modal_inheritance(self):
         """Test that ConfigModal properly inherits from ModalScreen."""
         mock_config = Mock(spec=Config)
         modal = ConfigModal(mock_config)
-        
+
         from textual.screen import ModalScreen
+
         assert isinstance(modal, ModalScreen)
-        
+
         # Should have the config attribute
-        assert hasattr(modal, 'config')
+        assert hasattr(modal, "config")
         assert modal.config == mock_config
diff --git a/tests/test_main.py b/tests/test_main.py
index 03c36fd..dd35d64 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -16,259 +16,277 @@ from hosts.core.config import Config
 
 class TestHostsManagerApp:
     """Test cases for the HostsManagerApp class."""
-    
+
     def test_app_initialization(self):
         """Test application initialization."""
-        with patch('hosts.tui.app.HostsParser'), patch('hosts.tui.app.Config'):
+        with patch("hosts.tui.app.HostsParser"), patch("hosts.tui.app.Config"):
             app = HostsManagerApp()
-            
+
             assert app.title == "/etc/hosts Manager"
             assert app.sub_title == ""  # Now set by update_status
             assert app.edit_mode is False
             assert app.selected_entry_index == 0
             assert app.sort_column == ""
             assert app.sort_ascending is True
-    
+
     def test_app_compose_method_exists(self):
         """Test that app has compose method."""
-        with patch('hosts.tui.app.HostsParser'), patch('hosts.tui.app.Config'):
+        with patch("hosts.tui.app.HostsParser"), patch("hosts.tui.app.Config"):
             app = HostsManagerApp()
-            
+
             # Test that compose method exists and is callable
-            assert hasattr(app, 'compose')
+            assert hasattr(app, "compose")
             assert callable(app.compose)
-    
+
     def test_load_hosts_file_success(self):
         """Test successful hosts file loading."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
+
         # Create test hosts file
         test_hosts = HostsFile()
         test_entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
         test_hosts.add_entry(test_entry)
-        
+
         mock_parser.parse.return_value = test_hosts
         mock_parser.get_file_info.return_value = {
-            'path': '/etc/hosts',
-            'exists': True,
-            'size': 100
+            "path": "/etc/hosts",
+            "exists": True,
+            "size": 100,
         }
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
             app.populate_entries_table = Mock()
             app.update_entry_details = Mock()
             app.set_timer = Mock()
-            
+
             app.load_hosts_file()
-            
+
             # Verify hosts file was loaded
             assert len(app.hosts_file.entries) == 1
             assert app.hosts_file.entries[0].ip_address == "127.0.0.1"
             mock_parser.parse.assert_called_once()
-    
+
     def test_load_hosts_file_not_found(self):
         """Test handling of missing hosts file."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
         mock_parser.parse.side_effect = FileNotFoundError("Hosts file not found")
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
             app.update_status = Mock()
-            
+
             app.load_hosts_file()
-            
+
             # Should handle error gracefully
-            app.update_status.assert_called_with("❌ Error loading hosts file: Hosts file not found")
-    
+            app.update_status.assert_called_with(
+                "❌ Error loading hosts file: Hosts file not found"
+            )
+
     def test_load_hosts_file_permission_error(self):
         """Test handling of permission denied error."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
         mock_parser.parse.side_effect = PermissionError("Permission denied")
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
             app.update_status = Mock()
-            
+
             app.load_hosts_file()
-            
+
             # Should handle error gracefully
-            app.update_status.assert_called_with("❌ Error loading hosts file: Permission denied")
-    
+            app.update_status.assert_called_with(
+                "❌ Error loading hosts file: Permission denied"
+            )
+
     def test_populate_entries_table_logic(self):
         """Test populating DataTable logic without UI dependencies."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = True
         mock_config.is_default_entry.return_value = False
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Mock the query_one method to return a mock table
             mock_table = Mock()
             app.query_one = Mock(return_value=mock_table)
-            
+
             # Add test entries
             app.hosts_file = HostsFile()
             active_entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
             inactive_entry = HostEntry(
-                ip_address="192.168.1.1", 
-                hostnames=["router"], 
-                is_active=False
+                ip_address="192.168.1.1", hostnames=["router"], is_active=False
             )
             app.hosts_file.add_entry(active_entry)
             app.hosts_file.add_entry(inactive_entry)
-            
+
             app.populate_entries_table()
-            
+
             # Verify table methods were called
             mock_table.clear.assert_called_once_with(columns=True)
             mock_table.add_columns.assert_called_once()
             assert mock_table.add_row.call_count == 2  # Two entries added
-    
+
     def test_update_entry_details_with_entry(self):
         """Test updating entry details pane."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
         mock_config.should_show_default_entries.return_value = True
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Mock the query_one method to return DataTable mock
             mock_details_table = Mock()
             mock_details_table.columns = []  # Mock empty columns list
             mock_edit_form = Mock()
-            
+
             def mock_query_one(selector, widget_type=None):
                 if selector == "#entry-details-table":
                     return mock_details_table
                 elif selector == "#entry-edit-form":
                     return mock_edit_form
                 return Mock()
-            
+
             app.query_one = mock_query_one
-            
+
             # Add test entry
             app.hosts_file = HostsFile()
             test_entry = HostEntry(
                 ip_address="127.0.0.1",
                 hostnames=["localhost", "local"],
-                comment="Test comment"
+                comment="Test comment",
             )
             app.hosts_file.add_entry(test_entry)
             app.selected_entry_index = 0
-            
+
             app.update_entry_details()
-            
+
             # Verify DataTable operations were called
             mock_details_table.remove_class.assert_called_with("hidden")
             mock_edit_form.add_class.assert_called_with("hidden")
             mock_details_table.clear.assert_called_once()
             mock_details_table.add_column.assert_called()
             mock_details_table.add_row.assert_called()
-    
+
     def test_update_entry_details_no_entries(self):
         """Test updating entry details with no entries."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Mock the query_one method to return DataTable mock
             mock_details_table = Mock()
             mock_details_table.columns = []  # Mock empty columns list
             mock_edit_form = Mock()
-            
+
             def mock_query_one(selector, widget_type=None):
                 if selector == "#entry-details-table":
                     return mock_details_table
                 elif selector == "#entry-edit-form":
                     return mock_edit_form
                 return Mock()
-            
+
             app.query_one = mock_query_one
             app.hosts_file = HostsFile()
-            
+
             app.update_entry_details()
-            
+
             # Verify DataTable operations were called for empty state
             mock_details_table.remove_class.assert_called_with("hidden")
             mock_edit_form.add_class.assert_called_with("hidden")
             mock_details_table.clear.assert_called_once()
             mock_details_table.add_column.assert_called_with("Field", key="field")
             mock_details_table.add_row.assert_called_with("No entries loaded")
-    
+
     def test_update_status_default(self):
         """Test status bar update with default information."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
         mock_parser.get_file_info.return_value = {
-            'path': '/etc/hosts',
-            'exists': True,
-            'size': 100
+            "path": "/etc/hosts",
+            "exists": True,
+            "size": 100,
         }
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Add test entries
             app.hosts_file = HostsFile()
-            app.hosts_file.add_entry(HostEntry(ip_address="127.0.0.1", hostnames=["localhost"]))
-            app.hosts_file.add_entry(HostEntry(
-                ip_address="192.168.1.1", 
-                hostnames=["router"], 
-                is_active=False
-            ))
-            
+            app.hosts_file.add_entry(
+                HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
+            )
+            app.hosts_file.add_entry(
+                HostEntry(
+                    ip_address="192.168.1.1", hostnames=["router"], is_active=False
+                )
+            )
+
             app.update_status()
-            
+
             # Verify sub_title was set correctly
             assert "Read-only mode" in app.sub_title
             assert "2 entries" in app.sub_title
             assert "1 active" in app.sub_title
-    
+
     def test_update_status_custom_message(self):
         """Test status bar update with custom message."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Mock set_timer and query_one to avoid event loop and UI issues
             app.set_timer = Mock()
             mock_status_bar = Mock()
             app.query_one = Mock(return_value=mock_status_bar)
-            
+
             # Add test hosts_file for subtitle generation
             app.hosts_file = HostsFile()
-            app.hosts_file.add_entry(HostEntry(ip_address="127.0.0.1", hostnames=["localhost"]))
-            app.hosts_file.add_entry(HostEntry(ip_address="192.168.1.1", hostnames=["router"], is_active=False))
-            
+            app.hosts_file.add_entry(
+                HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
+            )
+            app.hosts_file.add_entry(
+                HostEntry(
+                    ip_address="192.168.1.1", hostnames=["router"], is_active=False
+                )
+            )
+
             app.update_status("Custom status message")
-            
+
             # Verify status bar was updated with custom message
             mock_status_bar.update.assert_called_with("Custom status message")
             mock_status_bar.remove_class.assert_called_with("hidden")
@@ -277,225 +295,248 @@ class TestHostsManagerApp:
             assert "Read-only mode" in app.sub_title
             # Verify timer was set for auto-clearing
             app.set_timer.assert_called_once()
-    
+
     def test_action_reload(self):
         """Test reload action."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
             app.load_hosts_file = Mock()
             app.update_status = Mock()
-            
+
             app.action_reload()
-            
+
             app.load_hosts_file.assert_called_once()
             app.update_status.assert_called_with("Hosts file reloaded")
-    
+
     def test_action_help(self):
         """Test help action."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
             app.update_status = Mock()
-            
+
             app.action_help()
-            
+
             # Should update status with help message
             app.update_status.assert_called_once()
             call_args = app.update_status.call_args[0][0]
             assert "Help:" in call_args
-    
+
     def test_action_config(self):
         """Test config action opens modal."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
             app.push_screen = Mock()
-            
+
             app.action_config()
-            
+
             # Should push config modal screen
             app.push_screen.assert_called_once()
             args = app.push_screen.call_args[0]
             assert len(args) >= 1  # ConfigModal instance
-    
+
     def test_action_sort_by_ip_ascending(self):
         """Test sorting by IP address in ascending order."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Add test entries in reverse order
             app.hosts_file = HostsFile()
-            app.hosts_file.add_entry(HostEntry(ip_address="192.168.1.1", hostnames=["router"]))
-            app.hosts_file.add_entry(HostEntry(ip_address="127.0.0.1", hostnames=["localhost"]))
-            app.hosts_file.add_entry(HostEntry(ip_address="10.0.0.1", hostnames=["test"]))
-            
+            app.hosts_file.add_entry(
+                HostEntry(ip_address="192.168.1.1", hostnames=["router"])
+            )
+            app.hosts_file.add_entry(
+                HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
+            )
+            app.hosts_file.add_entry(
+                HostEntry(ip_address="10.0.0.1", hostnames=["test"])
+            )
+
             # Mock the table_handler methods to avoid UI queries
             app.table_handler.populate_entries_table = Mock()
             app.table_handler.restore_cursor_position = Mock()
             app.update_status = Mock()
-            
+
             app.action_sort_by_ip()
-            
+
             # Check that entries are sorted by IP address
-            assert app.hosts_file.entries[0].ip_address == "10.0.0.1"   # Sorted by IP
+            assert app.hosts_file.entries[0].ip_address == "10.0.0.1"  # Sorted by IP
             assert app.hosts_file.entries[1].ip_address == "127.0.0.1"
             assert app.hosts_file.entries[2].ip_address == "192.168.1.1"
-            
+
             assert app.sort_column == "ip"
             assert app.sort_ascending is True
             app.table_handler.populate_entries_table.assert_called_once()
-    
+
     def test_action_sort_by_hostname_ascending(self):
         """Test sorting by hostname in ascending order."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Add test entries in reverse alphabetical order
             app.hosts_file = HostsFile()
-            app.hosts_file.add_entry(HostEntry(ip_address="127.0.0.1", hostnames=["zebra"]))
-            app.hosts_file.add_entry(HostEntry(ip_address="192.168.1.1", hostnames=["alpha"]))
-            app.hosts_file.add_entry(HostEntry(ip_address="10.0.0.1", hostnames=["beta"]))
-            
+            app.hosts_file.add_entry(
+                HostEntry(ip_address="127.0.0.1", hostnames=["zebra"])
+            )
+            app.hosts_file.add_entry(
+                HostEntry(ip_address="192.168.1.1", hostnames=["alpha"])
+            )
+            app.hosts_file.add_entry(
+                HostEntry(ip_address="10.0.0.1", hostnames=["beta"])
+            )
+
             # Mock the table_handler methods to avoid UI queries
             app.table_handler.populate_entries_table = Mock()
             app.table_handler.restore_cursor_position = Mock()
             app.update_status = Mock()
-            
+
             app.action_sort_by_hostname()
-            
+
             # Check that entries are sorted alphabetically
             assert app.hosts_file.entries[0].hostnames[0] == "alpha"
             assert app.hosts_file.entries[1].hostnames[0] == "beta"
             assert app.hosts_file.entries[2].hostnames[0] == "zebra"
-            
+
             assert app.sort_column == "hostname"
             assert app.sort_ascending is True
             app.table_handler.populate_entries_table.assert_called_once()
-    
+
     def test_data_table_row_highlighted_event(self):
         """Test DataTable row highlighting event handling."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Mock the details_handler and table_handler methods
             app.details_handler.update_entry_details = Mock()
             app.table_handler.display_index_to_actual_index = Mock(return_value=2)
-            
+
             # Create mock event with required parameters
             mock_table = Mock()
             mock_table.id = "entries-table"
             event = Mock()
             event.data_table = mock_table
             event.cursor_row = 2
-            
+
             app.on_data_table_row_highlighted(event)
-            
+
             # Should update selected index and details
             assert app.selected_entry_index == 2
             app.details_handler.update_entry_details.assert_called_once()
             app.table_handler.display_index_to_actual_index.assert_called_once_with(2)
-    
+
     def test_data_table_header_selected_ip_column(self):
         """Test DataTable header selection for IP column."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
             app.action_sort_by_ip = Mock()
-            
+
             # Create mock event for IP column
             mock_table = Mock()
             mock_table.id = "entries-table"
             event = Mock()
             event.data_table = mock_table
             event.column_key = "IP Address"
-            
+
             app.on_data_table_header_selected(event)
-            
+
             app.action_sort_by_ip.assert_called_once()
-    
+
     def test_restore_cursor_position_logic(self):
         """Test cursor position restoration logic."""
         mock_parser = Mock(spec=HostsParser)
         mock_config = Mock(spec=Config)
-        
-        with patch('hosts.tui.app.HostsParser', return_value=mock_parser), \
-             patch('hosts.tui.app.Config', return_value=mock_config):
-            
+
+        with (
+            patch("hosts.tui.app.HostsParser", return_value=mock_parser),
+            patch("hosts.tui.app.Config", return_value=mock_config),
+        ):
             app = HostsManagerApp()
-            
+
             # Mock the query_one method to avoid UI dependencies
             mock_table = Mock()
             app.query_one = Mock(return_value=mock_table)
             app.update_entry_details = Mock()
-            
+
             # Add test entries
             app.hosts_file = HostsFile()
             entry1 = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
             entry2 = HostEntry(ip_address="192.168.1.1", hostnames=["router"])
             app.hosts_file.add_entry(entry1)
             app.hosts_file.add_entry(entry2)
-            
+
             # Test the logic without UI dependencies
             # Find the index of entry2
             target_index = None
             for i, entry in enumerate(app.hosts_file.entries):
-                if entry.ip_address == entry2.ip_address and entry.hostnames == entry2.hostnames:
+                if (
+                    entry.ip_address == entry2.ip_address
+                    and entry.hostnames == entry2.hostnames
+                ):
                     target_index = i
                     break
-            
+
             # Should find the matching entry at index 1
             assert target_index == 1
-    
+
     def test_app_bindings_defined(self):
         """Test that application has expected key bindings."""
-        with patch('hosts.tui.app.HostsParser'), patch('hosts.tui.app.Config'):
+        with patch("hosts.tui.app.HostsParser"), patch("hosts.tui.app.Config"):
             app = HostsManagerApp()
-            
+
             # Check that bindings are defined
             assert len(app.BINDINGS) >= 6
-            
+
             # Check specific bindings exist (handle both Binding objects and tuples)
             binding_keys = []
             for binding in app.BINDINGS:
-                if hasattr(binding, 'key'):
+                if hasattr(binding, "key"):
                     # Binding object
                     binding_keys.append(binding.key)
                 elif isinstance(binding, tuple) and len(binding) >= 1:
                     # Tuple format (key, action, description)
                     binding_keys.append(binding[0])
-            
+
             assert "q" in binding_keys
             assert "r" in binding_keys
             assert "h" in binding_keys
@@ -503,16 +544,17 @@ class TestHostsManagerApp:
             assert "n" in binding_keys
             assert "c" in binding_keys
             assert "ctrl+c" in binding_keys
-    
+
     def test_main_function(self):
         """Test main entry point function."""
-        with patch('hosts.main.HostsManagerApp') as mock_app_class:
+        with patch("hosts.main.HostsManagerApp") as mock_app_class:
             mock_app = Mock()
             mock_app_class.return_value = mock_app
-            
+
             from hosts.main import main
+
             main()
-            
+
             # Should create and run app
             mock_app_class.assert_called_once()
             mock_app.run.assert_called_once()
diff --git a/tests/test_manager.py b/tests/test_manager.py
index 9895b79..c088261 100644
--- a/tests/test_manager.py
+++ b/tests/test_manager.py
@@ -16,170 +16,165 @@ from src.hosts.core.models import HostEntry, HostsFile
 
 class TestPermissionManager:
     """Test the PermissionManager class."""
-    
+
     def test_init(self):
         """Test PermissionManager initialization."""
         pm = PermissionManager()
         assert not pm.has_sudo
         assert not pm._sudo_validated
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_request_sudo_already_available(self, mock_run):
         """Test requesting sudo when already available."""
         # Mock successful sudo -n true
         mock_run.return_value = Mock(returncode=0)
-        
+
         pm = PermissionManager()
         success, message = pm.request_sudo()
-        
+
         assert success
         assert "already available" in message
         assert pm.has_sudo
         assert pm._sudo_validated
-        
+
         mock_run.assert_called_once_with(
-            ['sudo', '-n', 'true'],
-            capture_output=True,
-            text=True,
-            timeout=5
+            ["sudo", "-n", "true"], capture_output=True, text=True, timeout=5
         )
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_request_sudo_prompt_success(self, mock_run):
         """Test requesting sudo with password prompt success."""
         # First call (sudo -n true) fails, second call (sudo -v) succeeds
         mock_run.side_effect = [
             Mock(returncode=1),  # sudo -n true fails
-            Mock(returncode=0)   # sudo -v succeeds
+            Mock(returncode=0),  # sudo -v succeeds
         ]
-        
+
         pm = PermissionManager()
         success, message = pm.request_sudo()
-        
+
         assert success
         assert "access granted" in message
         assert pm.has_sudo
         assert pm._sudo_validated
-        
+
         assert mock_run.call_count == 2
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_request_sudo_denied(self, mock_run):
         """Test requesting sudo when access is denied."""
         # Both calls fail
         mock_run.side_effect = [
             Mock(returncode=1),  # sudo -n true fails
-            Mock(returncode=1)   # sudo -v fails
+            Mock(returncode=1),  # sudo -v fails
         ]
-        
+
         pm = PermissionManager()
         success, message = pm.request_sudo()
-        
+
         assert not success
         assert "denied" in message
         assert not pm.has_sudo
         assert not pm._sudo_validated
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_request_sudo_timeout(self, mock_run):
         """Test requesting sudo with timeout."""
-        mock_run.side_effect = subprocess.TimeoutExpired(['sudo', '-n', 'true'], 5)
-        
+        mock_run.side_effect = subprocess.TimeoutExpired(["sudo", "-n", "true"], 5)
+
         pm = PermissionManager()
         success, message = pm.request_sudo()
-        
+
         assert not success
         assert "timed out" in message
         assert not pm.has_sudo
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_request_sudo_exception(self, mock_run):
         """Test requesting sudo with exception."""
         mock_run.side_effect = Exception("Test error")
-        
+
         pm = PermissionManager()
         success, message = pm.request_sudo()
-        
+
         assert not success
         assert "Test error" in message
         assert not pm.has_sudo
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_validate_permissions_success(self, mock_run):
         """Test validating permissions successfully."""
         mock_run.return_value = Mock(returncode=0)
-        
+
         pm = PermissionManager()
         pm.has_sudo = True
-        
+
         result = pm.validate_permissions("/etc/hosts")
-        
+
         assert result
         mock_run.assert_called_once_with(
-            ['sudo', '-n', 'test', '-w', '/etc/hosts'],
-            capture_output=True,
-            timeout=5
+            ["sudo", "-n", "test", "-w", "/etc/hosts"], capture_output=True, timeout=5
         )
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_validate_permissions_no_sudo(self, mock_run):
         """Test validating permissions without sudo."""
         pm = PermissionManager()
         pm.has_sudo = False
-        
+
         result = pm.validate_permissions("/etc/hosts")
-        
+
         assert not result
         mock_run.assert_not_called()
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_validate_permissions_failure(self, mock_run):
         """Test validating permissions failure."""
         mock_run.return_value = Mock(returncode=1)
-        
+
         pm = PermissionManager()
         pm.has_sudo = True
-        
+
         result = pm.validate_permissions("/etc/hosts")
-        
+
         assert not result
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_validate_permissions_exception(self, mock_run):
         """Test validating permissions with exception."""
         mock_run.side_effect = Exception("Test error")
-        
+
         pm = PermissionManager()
         pm.has_sudo = True
-        
+
         result = pm.validate_permissions("/etc/hosts")
-        
+
         assert not result
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_release_sudo(self, mock_run):
         """Test releasing sudo permissions."""
         pm = PermissionManager()
         pm.has_sudo = True
         pm._sudo_validated = True
-        
+
         pm.release_sudo()
-        
+
         assert not pm.has_sudo
         assert not pm._sudo_validated
-        mock_run.assert_called_once_with(['sudo', '-k'], capture_output=True, timeout=5)
-    
-    @patch('subprocess.run')
+        mock_run.assert_called_once_with(["sudo", "-k"], capture_output=True, timeout=5)
+
+    @patch("subprocess.run")
     def test_release_sudo_exception(self, mock_run):
         """Test releasing sudo with exception."""
         mock_run.side_effect = Exception("Test error")
-        
+
         pm = PermissionManager()
         pm.has_sudo = True
         pm._sudo_validated = True
-        
+
         pm.release_sudo()
-        
+
         # Should still reset state even if command fails
         assert not pm.has_sudo
         assert not pm._sudo_validated
@@ -187,7 +182,7 @@ class TestPermissionManager:
 
 class TestHostsManager:
     """Test the HostsManager class."""
-    
+
     def test_init(self):
         """Test HostsManager initialization."""
         with tempfile.NamedTemporaryFile() as temp_file:
@@ -195,273 +190,287 @@ class TestHostsManager:
             assert not manager.edit_mode
             assert manager._backup_path is None
             assert manager.parser.file_path == Path(temp_file.name)
-    
-    @patch('src.hosts.core.manager.HostsManager._create_backup')
+
+    @patch("src.hosts.core.manager.HostsManager._create_backup")
     def test_enter_edit_mode_success(self, mock_backup):
         """Test entering edit mode successfully."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
-            
+
             # Mock permission manager
-            manager.permission_manager.request_sudo = Mock(return_value=(True, "Success"))
+            manager.permission_manager.request_sudo = Mock(
+                return_value=(True, "Success")
+            )
             manager.permission_manager.validate_permissions = Mock(return_value=True)
-            
+
             success, message = manager.enter_edit_mode()
-            
+
             assert success
             assert "enabled" in message
             assert manager.edit_mode
             mock_backup.assert_called_once()
-    
+
     def test_enter_edit_mode_already_in_edit(self):
         """Test entering edit mode when already in edit mode."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             success, message = manager.enter_edit_mode()
-            
+
             assert success
             assert "Already in edit mode" in message
-    
+
     def test_enter_edit_mode_sudo_failure(self):
         """Test entering edit mode with sudo failure."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
-            
+
             # Mock permission manager failure
-            manager.permission_manager.request_sudo = Mock(return_value=(False, "Denied"))
-            
+            manager.permission_manager.request_sudo = Mock(
+                return_value=(False, "Denied")
+            )
+
             success, message = manager.enter_edit_mode()
-            
+
             assert not success
             assert "Cannot enter edit mode" in message
             assert not manager.edit_mode
-    
+
     def test_enter_edit_mode_permission_validation_failure(self):
         """Test entering edit mode with permission validation failure."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
-            
+
             # Mock permission manager
-            manager.permission_manager.request_sudo = Mock(return_value=(True, "Success"))
+            manager.permission_manager.request_sudo = Mock(
+                return_value=(True, "Success")
+            )
             manager.permission_manager.validate_permissions = Mock(return_value=False)
-            
+
             success, message = manager.enter_edit_mode()
-            
+
             assert not success
             assert "Cannot write to hosts file" in message
             assert not manager.edit_mode
-    
-    @patch('src.hosts.core.manager.HostsManager._create_backup')
+
+    @patch("src.hosts.core.manager.HostsManager._create_backup")
     def test_enter_edit_mode_backup_failure(self, mock_backup):
         """Test entering edit mode with backup failure."""
         mock_backup.side_effect = Exception("Backup failed")
-        
+
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
-            
+
             # Mock permission manager
-            manager.permission_manager.request_sudo = Mock(return_value=(True, "Success"))
+            manager.permission_manager.request_sudo = Mock(
+                return_value=(True, "Success")
+            )
             manager.permission_manager.validate_permissions = Mock(return_value=True)
-            
+
             success, message = manager.enter_edit_mode()
-            
+
             assert not success
             assert "Failed to create backup" in message
             assert not manager.edit_mode
-    
+
     def test_exit_edit_mode_success(self):
         """Test exiting edit mode successfully."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
             manager._backup_path = Path("/tmp/backup")
-            
+
             # Mock permission manager
             manager.permission_manager.release_sudo = Mock()
-            
+
             success, message = manager.exit_edit_mode()
-            
+
             assert success
             assert "disabled" in message
             assert not manager.edit_mode
             assert manager._backup_path is None
             manager.permission_manager.release_sudo.assert_called_once()
-    
+
     def test_exit_edit_mode_not_in_edit(self):
         """Test exiting edit mode when not in edit mode."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = False
-            
+
             success, message = manager.exit_edit_mode()
-            
+
             assert success
             assert "Already in read-only mode" in message
-    
+
     def test_exit_edit_mode_exception(self):
         """Test exiting edit mode with exception."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             # Mock permission manager to raise exception
-            manager.permission_manager.release_sudo = Mock(side_effect=Exception("Test error"))
-            
+            manager.permission_manager.release_sudo = Mock(
+                side_effect=Exception("Test error")
+            )
+
             success, message = manager.exit_edit_mode()
-            
+
             assert not success
             assert "Test error" in message
-    
+
     def test_toggle_entry_success(self):
         """Test toggling entry successfully."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             hosts_file = HostsFile()
-            entry = HostEntry("192.168.1.1", ["router"], is_active=True)  # Non-default entry
+            entry = HostEntry(
+                "192.168.1.1", ["router"], is_active=True
+            )  # Non-default entry
             hosts_file.entries.append(entry)
-            
+
             success, message = manager.toggle_entry(hosts_file, 0)
-            
+
             assert success
             assert "active to inactive" in message
             assert not hosts_file.entries[0].is_active
-    
+
     def test_toggle_entry_not_in_edit_mode(self):
         """Test toggling entry when not in edit mode."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = False
-            
+
             hosts_file = HostsFile()
-            
+
             success, message = manager.toggle_entry(hosts_file, 0)
-            
+
             assert not success
             assert "Not in edit mode" in message
-    
+
     def test_toggle_entry_invalid_index(self):
         """Test toggling entry with invalid index."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             hosts_file = HostsFile()
-            
+
             success, message = manager.toggle_entry(hosts_file, 0)
-            
+
             assert not success
             assert "Invalid entry index" in message
-    
+
     def test_move_entry_up_success(self):
         """Test moving entry up successfully."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             hosts_file = HostsFile()
             entry1 = HostEntry("10.0.0.1", ["test1"])  # Non-default entries
             entry2 = HostEntry("192.168.1.1", ["router"])
             hosts_file.entries.extend([entry1, entry2])
-            
+
             success, message = manager.move_entry_up(hosts_file, 1)
-            
+
             assert success
             assert "moved up" in message
             assert hosts_file.entries[0].hostnames[0] == "router"
             assert hosts_file.entries[1].hostnames[0] == "test1"
-    
+
     def test_move_entry_up_invalid_index(self):
         """Test moving entry up with invalid index."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             hosts_file = HostsFile()
             entry = HostEntry("127.0.0.1", ["localhost"])
             hosts_file.entries.append(entry)
-            
+
             success, message = manager.move_entry_up(hosts_file, 0)
-            
+
             assert not success
             assert "Cannot move entry up" in message
-    
+
     def test_move_entry_down_success(self):
         """Test moving entry down successfully."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             hosts_file = HostsFile()
             entry1 = HostEntry("10.0.0.1", ["test1"])  # Non-default entries
             entry2 = HostEntry("192.168.1.1", ["router"])
             hosts_file.entries.extend([entry1, entry2])
-            
+
             success, message = manager.move_entry_down(hosts_file, 0)
-            
+
             assert success
             assert "moved down" in message
             assert hosts_file.entries[0].hostnames[0] == "router"
             assert hosts_file.entries[1].hostnames[0] == "test1"
-    
+
     def test_move_entry_down_invalid_index(self):
         """Test moving entry down with invalid index."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             hosts_file = HostsFile()
             entry = HostEntry("127.0.0.1", ["localhost"])
             hosts_file.entries.append(entry)
-            
+
             success, message = manager.move_entry_down(hosts_file, 0)
-            
+
             assert not success
             assert "Cannot move entry down" in message
-    
+
     def test_update_entry_success(self):
         """Test updating entry successfully."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             hosts_file = HostsFile()
             entry = HostEntry("10.0.0.1", ["test"])  # Non-default entry
             hosts_file.entries.append(entry)
-            
+
             success, message = manager.update_entry(
                 hosts_file, 0, "192.168.1.1", ["newhost"], "New comment"
             )
-            
+
             assert success
             assert "updated successfully" in message
             assert hosts_file.entries[0].ip_address == "192.168.1.1"
             assert hosts_file.entries[0].hostnames == ["newhost"]
             assert hosts_file.entries[0].comment == "New comment"
-    
+
     def test_update_entry_invalid_data(self):
         """Test updating entry with invalid data."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             hosts_file = HostsFile()
-            entry = HostEntry("127.0.0.1", ["localhost"])  # Default entry - cannot be modified
+            entry = HostEntry(
+                "127.0.0.1", ["localhost"]
+            )  # Default entry - cannot be modified
             hosts_file.entries.append(entry)
-            
+
             success, message = manager.update_entry(
                 hosts_file, 0, "invalid-ip", ["newhost"]
             )
-            
+
             assert not success
             assert "Cannot modify default system entries" in message
-    
-    @patch('tempfile.NamedTemporaryFile')
-    @patch('subprocess.run')
-    @patch('os.unlink')
+
+    @patch("tempfile.NamedTemporaryFile")
+    @patch("subprocess.run")
+    @patch("os.unlink")
     def test_save_hosts_file_success(self, mock_unlink, mock_run, mock_temp):
         """Test saving hosts file successfully."""
         # Mock temporary file
@@ -470,143 +479,143 @@ class TestHostsManager:
         mock_temp_file.__enter__ = Mock(return_value=mock_temp_file)
         mock_temp_file.__exit__ = Mock(return_value=None)
         mock_temp.return_value = mock_temp_file
-        
+
         # Mock subprocess success
         mock_run.return_value = Mock(returncode=0)
-        
+
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
             manager.permission_manager.has_sudo = True
-            
+
             hosts_file = HostsFile()
             entry = HostEntry("127.0.0.1", ["localhost"])
             hosts_file.entries.append(entry)
-            
+
             success, message = manager.save_hosts_file(hosts_file)
-            
+
             assert success
             assert "saved successfully" in message
             mock_run.assert_called_once()
             mock_unlink.assert_called_once_with("/tmp/test.hosts")
-    
+
     def test_save_hosts_file_not_in_edit_mode(self):
         """Test saving hosts file when not in edit mode."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = False
-            
+
             hosts_file = HostsFile()
-            
+
             success, message = manager.save_hosts_file(hosts_file)
-            
+
             assert not success
             assert "Not in edit mode" in message
-    
+
     def test_save_hosts_file_no_sudo(self):
         """Test saving hosts file without sudo."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
             manager.permission_manager.has_sudo = False
-            
+
             hosts_file = HostsFile()
-            
+
             success, message = manager.save_hosts_file(hosts_file)
-            
+
             assert not success
             assert "No sudo permissions" in message
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_restore_backup_success(self, mock_run):
         """Test restoring backup successfully."""
         mock_run.return_value = Mock(returncode=0)
-        
+
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
-            
+
             # Create a mock backup file
             with tempfile.NamedTemporaryFile(delete=False) as backup_file:
                 manager._backup_path = Path(backup_file.name)
-            
+
             try:
                 success, message = manager.restore_backup()
-                
+
                 assert success
                 assert "restored successfully" in message
                 mock_run.assert_called_once()
             finally:
                 # Clean up
                 manager._backup_path.unlink()
-    
+
     def test_restore_backup_not_in_edit_mode(self):
         """Test restoring backup when not in edit mode."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = False
-            
+
             success, message = manager.restore_backup()
-            
+
             assert not success
             assert "Not in edit mode" in message
-    
+
     def test_restore_backup_no_backup(self):
         """Test restoring backup when no backup exists."""
         with tempfile.NamedTemporaryFile() as temp_file:
             manager = HostsManager(temp_file.name)
             manager.edit_mode = True
             manager._backup_path = None
-            
+
             success, message = manager.restore_backup()
-            
+
             assert not success
             assert "No backup available" in message
-    
-    @patch('subprocess.run')
-    @patch('tempfile.gettempdir')
-    @patch('time.time')
+
+    @patch("subprocess.run")
+    @patch("tempfile.gettempdir")
+    @patch("time.time")
     def test_create_backup_success(self, mock_time, mock_tempdir, mock_run):
         """Test creating backup successfully."""
         mock_time.return_value = 1234567890
         mock_tempdir.return_value = "/tmp"
         mock_run.side_effect = [
             Mock(returncode=0),  # cp command
-            Mock(returncode=0)   # chmod command
+            Mock(returncode=0),  # chmod command
         ]
-        
+
         # Create a real temporary file for testing
         with tempfile.NamedTemporaryFile(delete=False) as temp_file:
             temp_file.write(b"test content")
             temp_path = temp_file.name
-        
+
         try:
             manager = HostsManager(temp_path)
             manager._create_backup()
-            
+
             expected_backup = Path("/tmp/hosts-manager-backups/hosts.backup.1234567890")
             assert manager._backup_path == expected_backup
             assert mock_run.call_count == 2
         finally:
             # Clean up
             Path(temp_path).unlink()
-    
-    @patch('subprocess.run')
+
+    @patch("subprocess.run")
     def test_create_backup_failure(self, mock_run):
         """Test creating backup with failure."""
         mock_run.return_value = Mock(returncode=1, stderr="Permission denied")
-        
+
         # Create a real temporary file for testing
         with tempfile.NamedTemporaryFile(delete=False) as temp_file:
             temp_file.write(b"test content")
             temp_path = temp_file.name
-        
+
         try:
             manager = HostsManager(temp_path)
-            
+
             with pytest.raises(Exception) as exc_info:
                 manager._create_backup()
-            
+
             assert "Failed to create backup" in str(exc_info.value)
         finally:
             # Clean up
diff --git a/tests/test_models.py b/tests/test_models.py
index c88281b..62324c4 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -11,7 +11,7 @@ from hosts.core.models import HostEntry, HostsFile
 
 class TestHostEntry:
     """Test cases for the HostEntry class."""
-    
+
     def test_host_entry_creation(self):
         """Test basic host entry creation."""
         entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
@@ -20,105 +20,99 @@ class TestHostEntry:
         assert entry.is_active is True
         assert entry.comment is None
         assert entry.dns_name is None
-    
+
     def test_host_entry_with_comment(self):
         """Test host entry creation with comment."""
         entry = HostEntry(
             ip_address="192.168.1.1",
             hostnames=["router", "gateway"],
-            comment="Local router"
+            comment="Local router",
         )
         assert entry.comment == "Local router"
-    
+
     def test_host_entry_inactive(self):
         """Test inactive host entry creation."""
         entry = HostEntry(
-            ip_address="10.0.0.1",
-            hostnames=["test.local"],
-            is_active=False
+            ip_address="10.0.0.1", hostnames=["test.local"], is_active=False
         )
         assert entry.is_active is False
-    
+
     def test_invalid_ip_address(self):
         """Test that invalid IP addresses raise ValueError."""
         with pytest.raises(ValueError, match="Invalid IP address"):
             HostEntry(ip_address="invalid.ip", hostnames=["test"])
-    
+
     def test_empty_hostnames(self):
         """Test that empty hostnames list raises ValueError."""
         with pytest.raises(ValueError, match="At least one hostname is required"):
             HostEntry(ip_address="127.0.0.1", hostnames=[])
-    
+
     def test_invalid_hostname(self):
         """Test that invalid hostnames raise ValueError."""
         with pytest.raises(ValueError, match="Invalid hostname"):
             HostEntry(ip_address="127.0.0.1", hostnames=["invalid..hostname"])
-    
+
     def test_ipv6_address(self):
         """Test IPv6 address support."""
         entry = HostEntry(ip_address="::1", hostnames=["localhost"])
         assert entry.ip_address == "::1"
-    
+
     def test_to_hosts_line_active(self):
         """Test conversion to hosts file line format for active entry."""
         entry = HostEntry(
-            ip_address="127.0.0.1",
-            hostnames=["localhost", "local"],
-            comment="Loopback"
+            ip_address="127.0.0.1", hostnames=["localhost", "local"], comment="Loopback"
         )
         line = entry.to_hosts_line()
         assert line == "127.0.0.1\tlocalhost\tlocal\t# Loopback"
-    
+
     def test_to_hosts_line_inactive(self):
         """Test conversion to hosts file line format for inactive entry."""
         entry = HostEntry(
-            ip_address="192.168.1.1",
-            hostnames=["router"],
-            is_active=False
+            ip_address="192.168.1.1", hostnames=["router"], is_active=False
         )
         line = entry.to_hosts_line()
         assert line == "# 192.168.1.1\trouter"
-    
+
     def test_from_hosts_line_simple(self):
         """Test parsing simple hosts file line."""
         line = "127.0.0.1 localhost"
         entry = HostEntry.from_hosts_line(line)
-        
+
         assert entry is not None
         assert entry.ip_address == "127.0.0.1"
         assert entry.hostnames == ["localhost"]
         assert entry.is_active is True
         assert entry.comment is None
-    
+
     def test_from_hosts_line_with_comment(self):
         """Test parsing hosts file line with comment."""
         line = "192.168.1.1 router gateway # Local network"
         entry = HostEntry.from_hosts_line(line)
-        
+
         assert entry is not None
         assert entry.ip_address == "192.168.1.1"
         assert entry.hostnames == ["router", "gateway"]
         assert entry.comment == "Local network"
-    
+
     def test_from_hosts_line_inactive(self):
         """Test parsing inactive hosts file line."""
         line = "# 10.0.0.1 test.local"
         entry = HostEntry.from_hosts_line(line)
-        
+
         assert entry is not None
         assert entry.ip_address == "10.0.0.1"
         assert entry.hostnames == ["test.local"]
         assert entry.is_active is False
-    
+
     def test_from_hosts_line_empty(self):
         """Test parsing empty line returns None."""
         assert HostEntry.from_hosts_line("") is None
         assert HostEntry.from_hosts_line("   ") is None
-    
+
     def test_from_hosts_line_comment_only(self):
         """Test parsing comment-only line returns None."""
         assert HostEntry.from_hosts_line("# This is just a comment") is None
-    
+
     def test_from_hosts_line_invalid(self):
         """Test parsing invalid line returns None."""
         assert HostEntry.from_hosts_line("invalid line") is None
@@ -127,107 +121,105 @@ class TestHostEntry:
 
 class TestHostsFile:
     """Test cases for the HostsFile class."""
-    
+
     def test_hosts_file_creation(self):
         """Test basic hosts file creation."""
         hosts_file = HostsFile()
         assert len(hosts_file.entries) == 0
         assert len(hosts_file.header_comments) == 0
         assert len(hosts_file.footer_comments) == 0
-    
+
     def test_add_entry(self):
         """Test adding entries to hosts file."""
         hosts_file = HostsFile()
         entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
-        
+
         hosts_file.add_entry(entry)
         assert len(hosts_file.entries) == 1
         assert hosts_file.entries[0] == entry
-    
+
     def test_add_invalid_entry(self):
         """Test that adding invalid entry raises ValueError."""
         hosts_file = HostsFile()
-        
+
         with pytest.raises(ValueError):
             # This will fail validation in add_entry
             invalid_entry = HostEntry.__new__(HostEntry)  # Bypass __init__
             invalid_entry.ip_address = "invalid"
             invalid_entry.hostnames = ["test"]
             hosts_file.add_entry(invalid_entry)
-    
+
     def test_remove_entry(self):
         """Test removing entries from hosts file."""
         hosts_file = HostsFile()
         entry1 = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
         entry2 = HostEntry(ip_address="192.168.1.1", hostnames=["router"])
-        
+
         hosts_file.add_entry(entry1)
         hosts_file.add_entry(entry2)
-        
+
         hosts_file.remove_entry(0)
         assert len(hosts_file.entries) == 1
         assert hosts_file.entries[0] == entry2
-    
+
     def test_remove_entry_invalid_index(self):
         """Test removing entry with invalid index does nothing."""
         hosts_file = HostsFile()
         entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
         hosts_file.add_entry(entry)
-        
+
         hosts_file.remove_entry(10)  # Invalid index
         assert len(hosts_file.entries) == 1
-    
+
     def test_toggle_entry(self):
         """Test toggling entry active state."""
         hosts_file = HostsFile()
         entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
         hosts_file.add_entry(entry)
-        
+
         assert entry.is_active is True
         hosts_file.toggle_entry(0)
         assert entry.is_active is False
         hosts_file.toggle_entry(0)
         assert entry.is_active is True
-    
+
     def test_get_active_entries(self):
         """Test getting only active entries."""
         hosts_file = HostsFile()
         active_entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
         inactive_entry = HostEntry(
-            ip_address="192.168.1.1",
-            hostnames=["router"],
-            is_active=False
+            ip_address="192.168.1.1", hostnames=["router"], is_active=False
         )
-        
+
         hosts_file.add_entry(active_entry)
         hosts_file.add_entry(inactive_entry)
-        
+
         active_entries = hosts_file.get_active_entries()
         assert len(active_entries) == 1
         assert active_entries[0] == active_entry
-    
+
     def test_get_inactive_entries(self):
         """Test getting only inactive entries."""
         hosts_file = HostsFile()
         active_entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
         inactive_entry = HostEntry(
-            ip_address="192.168.1.1",
-            hostnames=["router"],
-            is_active=False
+            ip_address="192.168.1.1", hostnames=["router"], is_active=False
         )
-        
+
         hosts_file.add_entry(active_entry)
         hosts_file.add_entry(inactive_entry)
-        
+
         inactive_entries = hosts_file.get_inactive_entries()
         assert len(inactive_entries) == 1
         assert inactive_entries[0] == inactive_entry
-    
+
     def test_sort_by_ip(self):
         """Test sorting entries by IP address with default entries on top."""
         hosts_file = HostsFile()
         entry1 = HostEntry(ip_address="192.168.1.1", hostnames=["router"])
-        entry2 = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])  # Default entry
+        entry2 = HostEntry(
+            ip_address="127.0.0.1", hostnames=["localhost"]
+        )  # Default entry
         entry3 = HostEntry(ip_address="10.0.0.1", hostnames=["test"])
 
         hosts_file.add_entry(entry1)
@@ -238,62 +230,64 @@ class TestHostsFile:
 
         # Default entries should come first, then sorted non-default entries
         assert hosts_file.entries[0].ip_address == "127.0.0.1"  # Default entry first
-        assert hosts_file.entries[1].ip_address == "10.0.0.1"   # Then sorted non-defaults
+        assert (
+            hosts_file.entries[1].ip_address == "10.0.0.1"
+        )  # Then sorted non-defaults
         assert hosts_file.entries[2].ip_address == "192.168.1.1"
-    
+
     def test_sort_by_hostname(self):
         """Test sorting entries by hostname."""
         hosts_file = HostsFile()
         entry1 = HostEntry(ip_address="127.0.0.1", hostnames=["zebra"])
         entry2 = HostEntry(ip_address="192.168.1.1", hostnames=["alpha"])
         entry3 = HostEntry(ip_address="10.0.0.1", hostnames=["beta"])
-        
+
         hosts_file.add_entry(entry1)
         hosts_file.add_entry(entry2)
         hosts_file.add_entry(entry3)
-        
+
         hosts_file.sort_by_hostname()
-        
+
         assert hosts_file.entries[0].hostnames[0] == "alpha"
         assert hosts_file.entries[1].hostnames[0] == "beta"
         assert hosts_file.entries[2].hostnames[0] == "zebra"
-    
+
     def test_find_entries_by_hostname(self):
         """Test finding entries by hostname."""
         hosts_file = HostsFile()
         entry1 = HostEntry(ip_address="127.0.0.1", hostnames=["localhost", "local"])
         entry2 = HostEntry(ip_address="192.168.1.1", hostnames=["router"])
         entry3 = HostEntry(ip_address="10.0.0.1", hostnames=["test", "localhost"])
-        
+
         hosts_file.add_entry(entry1)
         hosts_file.add_entry(entry2)
         hosts_file.add_entry(entry3)
-        
+
         indices = hosts_file.find_entries_by_hostname("localhost")
         assert indices == [0, 2]
-        
+
         indices = hosts_file.find_entries_by_hostname("router")
         assert indices == [1]
-        
+
         indices = hosts_file.find_entries_by_hostname("nonexistent")
         assert indices == []
-    
+
     def test_find_entries_by_ip(self):
         """Test finding entries by IP address."""
         hosts_file = HostsFile()
         entry1 = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
         entry2 = HostEntry(ip_address="192.168.1.1", hostnames=["router"])
         entry3 = HostEntry(ip_address="127.0.0.1", hostnames=["local"])
-        
+
         hosts_file.add_entry(entry1)
         hosts_file.add_entry(entry2)
         hosts_file.add_entry(entry3)
-        
+
         indices = hosts_file.find_entries_by_ip("127.0.0.1")
         assert indices == [0, 2]
-        
+
         indices = hosts_file.find_entries_by_ip("192.168.1.1")
         assert indices == [1]
-        
+
         indices = hosts_file.find_entries_by_ip("10.0.0.1")
         assert indices == []
diff --git a/tests/test_parser.py b/tests/test_parser.py
index 24acea7..bed0d85 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -15,49 +15,49 @@ from hosts.core.models import HostEntry, HostsFile
 
 class TestHostsParser:
     """Test cases for the HostsParser class."""
-    
+
     def test_parser_initialization(self):
         """Test parser initialization with default and custom paths."""
         # Default path
         parser = HostsParser()
         assert str(parser.file_path) == "/etc/hosts"
-        
+
         # Custom path
         custom_path = "/tmp/test_hosts"
         parser = HostsParser(custom_path)
         assert str(parser.file_path) == custom_path
-    
+
     def test_parse_simple_hosts_file(self):
         """Test parsing a simple hosts file."""
         content = """127.0.0.1 localhost
 192.168.1.1 router
 """
-        
-        with tempfile.NamedTemporaryFile(mode='w', delete=False) as f:
+
+        with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
             f.write(content)
             f.flush()
-            
+
             parser = HostsParser(f.name)
             hosts_file = parser.parse()
-            
+
             assert len(hosts_file.entries) == 2
-            
+
             # Check first entry
             entry1 = hosts_file.entries[0]
             assert entry1.ip_address == "127.0.0.1"
             assert entry1.hostnames == ["localhost"]
             assert entry1.is_active is True
             assert entry1.comment is None
-            
+
             # Check second entry
             entry2 = hosts_file.entries[1]
             assert entry2.ip_address == "192.168.1.1"
             assert entry2.hostnames == ["router"]
             assert entry2.is_active is True
             assert entry2.comment is None
-        
+
         os.unlink(f.name)
-    
+
     def test_parse_hosts_file_with_comments(self):
         """Test parsing hosts file with comments and inactive entries."""
         content = """# This is a header comment
@@ -69,93 +69,93 @@ class TestHostsParser:
 
 # Footer comment
 """
-        
-        with tempfile.NamedTemporaryFile(mode='w', delete=False) as f:
+
+        with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
             f.write(content)
             f.flush()
-            
+
             parser = HostsParser(f.name)
             hosts_file = parser.parse()
-            
+
             # Check header comments
             assert len(hosts_file.header_comments) == 2
             assert hosts_file.header_comments[0] == "This is a header comment"
             assert hosts_file.header_comments[1] == "Another header comment"
-            
+
             # Check entries
             assert len(hosts_file.entries) == 3
-            
+
             # Active entry with comment
             entry1 = hosts_file.entries[0]
             assert entry1.ip_address == "127.0.0.1"
             assert entry1.hostnames == ["localhost", "loopback"]
             assert entry1.comment == "Loopback address"
             assert entry1.is_active is True
-            
+
             # Another active entry
             entry2 = hosts_file.entries[1]
             assert entry2.ip_address == "192.168.1.1"
             assert entry2.hostnames == ["router", "gateway"]
             assert entry2.comment == "Local router"
             assert entry2.is_active is True
-            
+
             # Inactive entry
             entry3 = hosts_file.entries[2]
             assert entry3.ip_address == "10.0.0.1"
             assert entry3.hostnames == ["test.local"]
             assert entry3.comment == "Disabled test entry"
             assert entry3.is_active is False
-            
+
             # Check footer comments
             assert len(hosts_file.footer_comments) == 1
             assert hosts_file.footer_comments[0] == "Footer comment"
-        
+
         os.unlink(f.name)
-    
+
     def test_parse_empty_file(self):
         """Test parsing an empty hosts file."""
-        with tempfile.NamedTemporaryFile(mode='w', delete=False) as f:
+        with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
             f.write("")
             f.flush()
-            
+
             parser = HostsParser(f.name)
             hosts_file = parser.parse()
-            
+
             assert len(hosts_file.entries) == 0
             assert len(hosts_file.header_comments) == 0
             assert len(hosts_file.footer_comments) == 0
-        
+
         os.unlink(f.name)
-    
+
     def test_parse_comments_only_file(self):
         """Test parsing a file with only comments."""
         content = """# This is a comment
 # Another comment
 # Yet another comment
 """
-        
-        with tempfile.NamedTemporaryFile(mode='w', delete=False) as f:
+
+        with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
             f.write(content)
             f.flush()
-            
+
             parser = HostsParser(f.name)
             hosts_file = parser.parse()
-            
+
             assert len(hosts_file.entries) == 0
             assert len(hosts_file.header_comments) == 3
             assert hosts_file.header_comments[0] == "This is a comment"
             assert hosts_file.header_comments[1] == "Another comment"
             assert hosts_file.header_comments[2] == "Yet another comment"
-        
+
         os.unlink(f.name)
-    
+
     def test_parse_nonexistent_file(self):
         """Test parsing a nonexistent file raises FileNotFoundError."""
         parser = HostsParser("/nonexistent/path/hosts")
-        
+
         with pytest.raises(FileNotFoundError):
             parser.parse()
-    
+
     def test_serialize_simple_hosts_file(self):
         """Test serializing a simple hosts file."""
         hosts_file = HostsFile()
@@ -177,30 +177,24 @@ class TestHostsParser:
 192.168.1.1\trouter
 """
         assert content == expected
-    
+
     def test_serialize_hosts_file_with_comments(self):
         """Test serializing hosts file with comments."""
         hosts_file = HostsFile()
         hosts_file.header_comments = ["Header comment 1", "Header comment 2"]
         hosts_file.footer_comments = ["Footer comment"]
-        
+
         entry1 = HostEntry(
-            ip_address="127.0.0.1",
-            hostnames=["localhost"],
-            comment="Loopback"
+            ip_address="127.0.0.1", hostnames=["localhost"], comment="Loopback"
         )
-        entry2 = HostEntry(
-            ip_address="10.0.0.1",
-            hostnames=["test"],
-            is_active=False
-        )
-        
+        entry2 = HostEntry(ip_address="10.0.0.1", hostnames=["test"], is_active=False)
+
         hosts_file.add_entry(entry1)
         hosts_file.add_entry(entry2)
-        
+
         parser = HostsParser()
         content = parser.serialize(hosts_file)
-        
+
         expected = """# Header comment 1
 # Header comment 2
 # Managed by hosts - https://git.s1q.dev/phg/hosts
@@ -210,13 +204,13 @@ class TestHostsParser:
 # Footer comment
 """
         assert content == expected
-    
+
     def test_serialize_empty_hosts_file(self):
         """Test serializing an empty hosts file."""
         hosts_file = HostsFile()
         parser = HostsParser()
         content = parser.serialize(hosts_file)
-        
+
         expected = """# #
 # Host Database
 #
@@ -224,19 +218,19 @@ class TestHostsParser:
 # #
 """
         assert content == expected
-    
+
     def test_write_hosts_file(self):
         """Test writing hosts file to disk."""
         hosts_file = HostsFile()
         entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
         hosts_file.add_entry(entry)
-        
+
         with tempfile.NamedTemporaryFile(delete=False) as f:
             parser = HostsParser(f.name)
             parser.write(hosts_file, backup=False)
-            
+
             # Read back and verify
-            with open(f.name, 'r') as read_file:
+            with open(f.name, "r") as read_file:
                 content = read_file.read()
                 expected = """# #
 # Host Database
@@ -246,37 +240,37 @@ class TestHostsParser:
 127.0.0.1\tlocalhost
 """
                 assert content == expected
-        
+
         os.unlink(f.name)
-    
+
     def test_write_hosts_file_with_backup(self):
         """Test writing hosts file with backup creation."""
         # Create initial file
         initial_content = "192.168.1.1 router\n"
-        
-        with tempfile.NamedTemporaryFile(mode='w', delete=False) as f:
+
+        with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
             f.write(initial_content)
             f.flush()
-            
+
             # Create new hosts file to write
             hosts_file = HostsFile()
             entry = HostEntry(ip_address="127.0.0.1", hostnames=["localhost"])
             hosts_file.add_entry(entry)
-            
+
             parser = HostsParser(f.name)
             parser.write(hosts_file, backup=True)
-            
+
             # Check that backup was created
-            backup_path = Path(f.name).with_suffix('.bak')
+            backup_path = Path(f.name).with_suffix(".bak")
             assert backup_path.exists()
-            
+
             # Check backup content
-            with open(backup_path, 'r') as backup_file:
+            with open(backup_path, "r") as backup_file:
                 backup_content = backup_file.read()
                 assert backup_content == initial_content
-            
+
             # Check new content
-            with open(f.name, 'r') as new_file:
+            with open(f.name, "r") as new_file:
                 new_content = new_file.read()
                 expected = """# #
 # Host Database
@@ -286,61 +280,61 @@ class TestHostsParser:
 127.0.0.1\tlocalhost
 """
                 assert new_content == expected
-            
+
             # Cleanup
             os.unlink(backup_path)
-        
+
         os.unlink(f.name)
-    
+
     def test_validate_write_permissions(self):
         """Test write permission validation."""
         # Test with a temporary file (should be writable)
         with tempfile.NamedTemporaryFile() as f:
             parser = HostsParser(f.name)
             assert parser.validate_write_permissions() is True
-        
+
         # Test with a nonexistent file in /tmp (should be writable)
         parser = HostsParser("/tmp/test_hosts_nonexistent")
         assert parser.validate_write_permissions() is True
-        
+
         # Test with a path that likely doesn't have write permissions
         parser = HostsParser("/root/test_hosts")
         # This might be True if running as root, so we can't assert False
         result = parser.validate_write_permissions()
         assert isinstance(result, bool)
-    
+
     def test_get_file_info(self):
         """Test getting file information."""
         content = "127.0.0.1 localhost\n"
-        
-        with tempfile.NamedTemporaryFile(mode='w', delete=False) as f:
+
+        with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
             f.write(content)
             f.flush()
-            
+
             parser = HostsParser(f.name)
             info = parser.get_file_info()
-            
-            assert info['path'] == f.name
-            assert info['exists'] is True
-            assert info['readable'] is True
-            assert info['size'] == len(content)
-            assert info['modified'] is not None
-            assert isinstance(info['modified'], float)
-        
+
+            assert info["path"] == f.name
+            assert info["exists"] is True
+            assert info["readable"] is True
+            assert info["size"] == len(content)
+            assert info["modified"] is not None
+            assert isinstance(info["modified"], float)
+
         os.unlink(f.name)
-    
+
     def test_get_file_info_nonexistent(self):
         """Test getting file information for nonexistent file."""
         parser = HostsParser("/nonexistent/path")
         info = parser.get_file_info()
-        
-        assert info['path'] == "/nonexistent/path"
-        assert info['exists'] is False
-        assert info['readable'] is False
-        assert info['writable'] is False
-        assert info['size'] == 0
-        assert info['modified'] is None
-    
+
+        assert info["path"] == "/nonexistent/path"
+        assert info["exists"] is False
+        assert info["readable"] is False
+        assert info["writable"] is False
+        assert info["size"] == 0
+        assert info["modified"] is None
+
     def test_round_trip_parsing(self):
         """Test that parsing and serializing preserves content."""
         original_content = """# System hosts file
@@ -353,26 +347,26 @@ class TestHostsParser:
 
 # End of file
 """
-        
-        with tempfile.NamedTemporaryFile(mode='w', delete=False) as f:
+
+        with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
             f.write(original_content)
             f.flush()
-            
+
             # Parse and serialize
             parser = HostsParser(f.name)
             hosts_file = parser.parse()
-            
+
             # Write back and read
             parser.write(hosts_file, backup=False)
-            
-            with open(f.name, 'r') as read_file:
+
+            with open(f.name, "r") as read_file:
                 final_content = read_file.read()
-            
+
             # The content should be functionally equivalent
             # (though formatting might differ slightly with tabs)
             assert "127.0.0.1\tlocalhost\tloopback\t# Local loopback" in final_content
             assert "::1\t\tlocalhost\t# IPv6 loopback" in final_content
             assert "192.168.1.1\trouter\t\tgateway\t# Local router" in final_content
             assert "# 10.0.0.1\ttest.local\t# Test entry (disabled)" in final_content
-        
+
         os.unlink(f.name)
diff --git a/tests/test_save_confirmation_modal.py b/tests/test_save_confirmation_modal.py
index 705309c..cd1bd52 100644
--- a/tests/test_save_confirmation_modal.py
+++ b/tests/test_save_confirmation_modal.py
@@ -279,7 +279,7 @@ class TestSaveConfirmationIntegration:
         """Test exit_edit_entry_mode cleans up properly."""
         app.entry_edit_mode = True
         app.original_entry_values = {"test": "data"}
-        
+
         # Mock the details_handler and query_one methods
         app.details_handler.update_entry_details = Mock()
         app.query_one = Mock()