diff --git a/src/app.rs b/src/app.rs
index 11a7bc7..bac4047 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -1,21 +1,32 @@
 use crate::format::EnvVar;
 use tui_input::Input;
 
+/// Represents the current operating mode of the application.
 pub enum Mode {
+    /// Standard navigation and command mode.
     Normal,
+    /// Active text entry mode for modifying values.
     Insert,
 }
 
+/// The core application state, holding all configuration variables and UI status.
 pub struct App {
+    /// The list of configuration variables being edited.
     pub vars: Vec<EnvVar>,
+    /// Index of the currently selected variable in the list.
     pub selected: usize,
+    /// The current interaction mode (Normal or Insert).
     pub mode: Mode,
+    /// Whether the main application loop should continue running.
     pub running: bool,
+    /// An optional message to display in the status bar (e.g., "Saved to .env").
     pub status_message: Option<String>,
+    /// The active text input buffer for the selected variable.
     pub input: Input,
 }
 
 impl App {
+    /// Initializes a new application instance with the provided variables.
     pub fn new(vars: Vec<EnvVar>) -> Self {
         let initial_input = vars.get(0).map(|v| v.value.clone()).unwrap_or_default();
         Self {
@@ -28,6 +39,7 @@ impl App {
         }
     }
 
+    /// Moves the selection to the next variable in the list, wrapping around if necessary.
     pub fn next(&mut self) {
         if !self.vars.is_empty() {
             self.selected = (self.selected + 1) % self.vars.len();
@@ -35,6 +47,7 @@ impl App {
         }
     }
 
+    /// Moves the selection to the previous variable in the list, wrapping around if necessary.
     pub fn previous(&mut self) {
         if !self.vars.is_empty() {
             if self.selected == 0 {
@@ -46,30 +59,29 @@ impl App {
         }
     }
 
+    /// Updates the input buffer to reflect the value of the currently selected variable.
     pub fn sync_input_with_selected(&mut self) {
         if let Some(var) = self.vars.get(self.selected) {
             self.input = Input::new(var.value.clone());
         }
     }
 
+    /// Commits the current text in the input buffer back to the selected variable's value.
     pub fn commit_input(&mut self) {
         if let Some(var) = self.vars.get_mut(self.selected) {
             var.value = self.input.value().to_string();
         }
     }
 
+    /// Transitions the application into Insert Mode.
     pub fn enter_insert(&mut self) {
         self.mode = Mode::Insert;
         self.status_message = None;
     }
 
+    /// Commits the current input and transitions the application into Normal Mode.
     pub fn enter_normal(&mut self) {
         self.commit_input();
         self.mode = Mode::Normal;
     }
-
-    #[allow(dead_code)]
-    pub fn quit(&mut self) {
-        self.running = false;
-    }
 }
diff --git a/src/cli.rs b/src/cli.rs
index 447e9d5..1a19274 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,13 +1,14 @@
 use clap::Parser;
 use std::path::PathBuf;
 
+/// mould: A TUI tool to generate and edit configuration files (.env, json, yaml, toml)
 #[derive(Parser, Debug)]
-#[command(author, version, about = "mould: A TUI tool to generate and edit configuration files (.env, json, yaml, toml)")]
+#[command(author, version, about)]
 pub struct Cli {
     /// The input template file (e.g., .env.example, config.json.template, docker-compose.yml)
     pub input: PathBuf,
 
-    /// Optional output file. If not provided, it will be inferred (e.g., .env.example -> .env, docker-compose.yml -> docker-compose.override.yml)
+    /// Optional output file. If not provided, it will be inferred.
     #[arg(short, long)]
     pub output: Option<PathBuf>,
 
@@ -16,6 +17,7 @@ pub struct Cli {
     pub format: Option<String>,
 }
 
+/// Parses and returns the command-line arguments.
 pub fn parse() -> Cli {
     Cli::parse()
 }
diff --git a/src/config.rs b/src/config.rs
index 8029cd2..8ea7df6 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -2,22 +2,34 @@ use serde::{Deserialize, Serialize};
 use std::fs;
 use ratatui::style::Color;
 
+/// Configuration for the application's appearance.
 #[derive(Debug, Deserialize, Serialize, Clone)]
 pub struct ThemeConfig {
+    /// If true, skip rendering the background block to let the terminal's transparency show.
     #[serde(default)]
     pub transparent: bool,
+    /// Color for standard background areas (when not transparent).
     pub crust: String,
+    /// Dark surface color for UI elements like the status bar.
     pub surface0: String,
+    /// Light surface color for borders and dividers.
     pub surface1: String,
+    /// Default text color.
     pub text: String,
+    /// Color for selection highlighting and normal mode tag.
     pub blue: String,
+    /// Color for insert mode highlighting and success status.
     pub green: String,
+    /// Accent color for configuration keys.
     pub lavender: String,
+    /// Accent color for primary section titles.
     pub mauve: String,
+    /// Accent color for input field titles.
     pub peach: String,
 }
 
 impl ThemeConfig {
+    /// Internal helper to parse a hex color string ("#RRGGBB") into a TUI Color.
     fn parse_hex(hex: &str) -> Color {
         let hex = hex.trim_start_matches('#');
         if hex.len() == 6 {
@@ -42,6 +54,7 @@ impl ThemeConfig {
 }
 
 impl Default for ThemeConfig {
+    /// Default theme: Catppuccin Mocha.
     fn default() -> Self {
         Self {
             transparent: false,
@@ -58,6 +71,7 @@ impl Default for ThemeConfig {
     }
 }
 
+/// Custom keybindings for navigation and application control.
 #[derive(Debug, Deserialize, Serialize, Clone)]
 pub struct KeybindsConfig {
     pub down: String,
@@ -81,6 +95,7 @@ impl Default for KeybindsConfig {
     }
 }
 
+/// Root configuration structure for mould.
 #[derive(Debug, Deserialize, Serialize, Default, Clone)]
 pub struct Config {
     #[serde(default)]
@@ -89,6 +104,8 @@ pub struct Config {
     pub keybinds: KeybindsConfig,
 }
 
+/// Loads the configuration from the user's home config directory (~/.config/mould/config.toml).
+/// Falls back to default settings if no configuration is found.
 pub fn load_config() -> Config {
     if let Some(mut config_dir) = dirs::config_dir() {
         config_dir.push("mould");
diff --git a/src/main.rs b/src/main.rs
index ed076ab..d5e067c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -20,23 +20,32 @@ use crossterm::{
 };
 use ratatui::{backend::CrosstermBackend, Terminal};
 
+/// Helper to automatically determine the output file path based on common naming conventions.
 fn determine_output_path(input: &Path) -> PathBuf {
     let file_name = input.file_name().unwrap_or_default().to_string_lossy();
+    
+    // .env.example -> .env
     if file_name == ".env.example" {
         return input.with_file_name(".env");
     }
+    
+    // docker-compose.yml -> docker-compose.override.yml
     if file_name == "docker-compose.yml" {
         return input.with_file_name("docker-compose.override.yml");
     }
     if file_name == "docker-compose.yaml" {
         return input.with_file_name("docker-compose.override.yaml");
     }
+    
+    // config.example.json -> config.json
     if file_name.ends_with(".example.json") {
         return input.with_file_name(file_name.replace(".example.json", ".json"));
     }
     if file_name.ends_with(".template.json") {
         return input.with_file_name(file_name.replace(".template.json", ".json"));
     }
+    
+    // Fallback: append .out to the extension
     input.with_extension(format!(
         "{}.out",
         input.extension().unwrap_or_default().to_string_lossy()
@@ -44,6 +53,7 @@ fn determine_output_path(input: &Path) -> PathBuf {
 }
 
 fn main() -> Result<(), Box<dyn Error>> {
+    // Parse CLI arguments
     let args = cli::parse();
 
     let input_path = args.input;
@@ -52,13 +62,16 @@ fn main() -> Result<(), Box<dyn Error>> {
         return Ok(());
     }
 
+    // Detect format and select appropriate handler
     let format_type = detect_format(&input_path, args.format);
     let handler = get_handler(format_type);
 
+    // Determine where to save the result
     let output_path = args
         .output
         .unwrap_or_else(|| determine_output_path(&input_path));
 
+    // Initial parsing of the template file
     let mut vars = handler.parse(&input_path).unwrap_or_else(|err| {
         println!("Error parsing input file: {}", err);
         vec![]
@@ -72,22 +85,27 @@ fn main() -> Result<(), Box<dyn Error>> {
         return Ok(());
     }
 
+    // Merge values from an existing output file if it exists
     if let Err(e) = handler.merge(&output_path, &mut vars) {
         println!("Warning: Could not merge existing output file: {}", e);
     }
 
+    // Load user configuration and initialize application state
     let config = load_config();
     let mut app = App::new(vars);
 
+    // Initialize terminal into raw mode and enter alternate screen
     enable_raw_mode()?;
     let mut stdout = io::stdout();
     execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
     let backend = CrosstermBackend::new(stdout);
     let mut terminal = Terminal::new(backend)?;
 
+    // Instantiate the runner and start the application loop
     let mut runner = AppRunner::new(&mut terminal, &mut app, &config, &output_path, handler.as_ref());
     let res = runner.run();
 
+    // Clean up terminal state on exit
     disable_raw_mode()?;
     execute!(
         terminal.backend_mut(),
diff --git a/src/runner.rs b/src/runner.rs
index 5598d63..c31e3a4 100644
--- a/src/runner.rs
+++ b/src/runner.rs
@@ -8,12 +8,19 @@ use std::io;
 use std::path::Path;
 use tui_input::backend::crossterm::EventHandler;
 
+/// Manages the main application execution loop, event handling, and terminal interaction.
 pub struct AppRunner<'a, B: Backend> {
+    /// Reference to the terminal instance.
     terminal: &'a mut Terminal<B>,
+    /// Mutable reference to the application state.
     app: &'a mut App,
+    /// Loaded user configuration.
     config: &'a Config,
+    /// Path where the final configuration will be saved.
     output_path: &'a Path,
+    /// Handler for the specific file format (env, json, yaml, toml).
     handler: &'a dyn FormatHandler,
+    /// Buffer for storing active command entry (e.g., ":w").
     command_buffer: String,
 }
 
@@ -21,6 +28,7 @@ impl<'a, B: Backend> AppRunner<'a, B>
 where
     io::Error: From<B::Error>,
 {
+    /// Creates a new runner instance.
     pub fn new(
         terminal: &'a mut Terminal<B>,
         app: &'a mut App,
@@ -38,9 +46,11 @@ where
         }
     }
 
+    /// Starts the main application loop.
     pub fn run(&mut self) -> io::Result<()> {
         while self.app.running {
-            self.terminal.draw(|f| crate::ui::draw(f, self.app, self.config))?;
+            self.terminal
+                .draw(|f| crate::ui::draw(f, self.app, self.config))?;
 
             if let Event::Key(key) = event::read()? {
                 self.handle_key_event(key)?;
@@ -49,6 +59,7 @@ where
         Ok(())
     }
 
+    /// Primary dispatcher for all keyboard events.
     fn handle_key_event(&mut self, key: KeyEvent) -> io::Result<()> {
         match self.app.mode {
             Mode::Normal => self.handle_normal_mode(key),
@@ -56,6 +67,7 @@ where
         }
     }
 
+    /// Handles keys in Normal mode, separating navigation from command entry.
     fn handle_normal_mode(&mut self, key: KeyEvent) -> io::Result<()> {
         if !self.command_buffer.is_empty() {
             self.handle_command_mode(key)
@@ -64,6 +76,7 @@ where
         }
     }
 
+    /// Logic for entering and executing ":" style commands.
     fn handle_command_mode(&mut self, key: KeyEvent) -> io::Result<()> {
         match key.code {
             KeyCode::Enter => {
@@ -90,6 +103,7 @@ where
         }
     }
 
+    /// Handles primary navigation (j/k) and transitions to insert or command modes.
     fn handle_navigation_mode(&mut self, key: KeyEvent) -> io::Result<()> {
         if let KeyCode::Char(c) = key.code {
             let c_str = c.to_string();
@@ -116,6 +130,7 @@ where
         Ok(())
     }
 
+    /// Delegates key events to the `tui_input` handler during active editing.
     fn handle_insert_mode(&mut self, key: KeyEvent) -> io::Result<()> {
         match key.code {
             KeyCode::Esc | KeyCode::Enter => {
@@ -128,6 +143,7 @@ where
         Ok(())
     }
 
+    /// Logic to map command strings (like ":w") to internal application actions.
     fn execute_command(&mut self, cmd: &str) -> io::Result<()> {
         if cmd == self.config.keybinds.save {
             self.save_file()
@@ -144,6 +160,7 @@ where
         }
     }
 
+    /// Attempts to write the current app state to the specified output file.
     fn save_file(&mut self) -> io::Result<()> {
         if self.handler.write(self.output_path, &self.app.vars).is_ok() {
             self.app.status_message = Some(format!("Saved to {}", self.output_path.display()));
@@ -153,6 +170,7 @@ where
         Ok(())
     }
 
+    /// Synchronizes the status bar display with the active command buffer.
     fn sync_command_status(&mut self) {
         if self.command_buffer.is_empty() {
             self.app.status_message = None;
diff --git a/src/ui.rs b/src/ui.rs
index b35743e..8beb046 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -8,36 +8,42 @@ use ratatui::{
     Frame,
 };
 
+/// Renders the main application interface using ratatui.
 pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
     let theme = &config.theme;
     let size = f.area();
 
-    // Background
+    // Render the main background (optional based on transparency config).
     if !theme.transparent {
-        f.render_widget(Block::default().style(Style::default().bg(theme.crust())), size);
+        f.render_widget(
+            Block::default().style(Style::default().bg(theme.crust())),
+            size,
+        );
     }
 
-    // Main layout with horizontal padding
+    // Horizontal layout with 1-character side margins.
     let outer_layout = Layout::default()
         .direction(Direction::Horizontal)
         .constraints([
-            Constraint::Length(1), // Left padding
-            Constraint::Min(0),    // Content
-            Constraint::Length(1), // Right padding
+            Constraint::Length(1),
+            Constraint::Min(0),
+            Constraint::Length(1),
         ])
         .split(size);
 
+    // Vertical layout for the main UI components.
     let chunks = Layout::default()
         .direction(Direction::Vertical)
         .constraints([
-            Constraint::Length(1), // Top padding
-            Constraint::Min(3),    // List
-            Constraint::Length(3), // Input area
-            Constraint::Length(1), // Bottom padding
+            Constraint::Length(1), // Top margin
+            Constraint::Min(3),    // Main list
+            Constraint::Length(3), // Focused input field
+            Constraint::Length(1), // Spacer
             Constraint::Length(1), // Status bar
         ])
         .split(outer_layout[1]);
 
+    // Calculate alignment for the key-value separator based on the longest key.
     let max_key_len = app
         .vars
         .iter()
@@ -46,14 +52,15 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
         .unwrap_or(20)
         .min(40);
 
-    // List
+    // Build the interactive list of configuration variables.
     let items: Vec<ListItem> = app
         .vars
         .iter()
         .enumerate()
         .map(|(i, var)| {
             let is_selected = i == app.selected;
-            
+
+            // Show live input text for the selected item if in Insert mode.
             let val = if is_selected && matches!(app.mode, Mode::Insert) {
                 app.input.value()
             } else {
@@ -61,7 +68,9 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
             };
 
             let key_style = if is_selected {
-                Style::default().fg(theme.crust()).add_modifier(Modifier::BOLD)
+                Style::default()
+                    .fg(theme.crust())
+                    .add_modifier(Modifier::BOLD)
             } else {
                 Style::default().fg(theme.lavender())
             };
@@ -73,7 +82,10 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
             };
 
             let line = Line::from(vec![
-                Span::styled(format!(" {:<width$} ", var.key, width = max_key_len), key_style),
+                Span::styled(
+                    format!(" {:<width$} ", var.key, width = max_key_len),
+                    key_style,
+                ),
                 Span::styled("│ ", Style::default().fg(theme.surface1())),
                 Span::styled(format!(" {} ", val), value_style),
             ]);
@@ -88,21 +100,20 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
         })
         .collect();
 
-    let list = List::new(items)
-        .block(
-            Block::default()
-                .borders(Borders::ALL)
-                .border_type(BorderType::Rounded)
-                .title(" Config Variables ")
-                .title_style(Style::default().fg(theme.mauve()).add_modifier(Modifier::BOLD))
-                .border_style(Style::default().fg(theme.surface1())),
-        );
+    let list = List::new(items).block(
+        Block::default()
+            .borders(Borders::ALL)
+            .border_type(BorderType::Rounded)
+            .title(" Config Variables ")
+            .title_style(Style::default().fg(theme.mauve()).add_modifier(Modifier::BOLD))
+            .border_style(Style::default().fg(theme.surface1())),
+    );
 
     let mut state = ListState::default();
     state.select(Some(app.selected));
     f.render_stateful_widget(list, chunks[1], &mut state);
 
-    // Input Area
+    // Render the focused input area.
     let current_var = app.vars.get(app.selected);
     let input_title = if let Some(var) = current_var {
         if var.default_value.is_empty() {
@@ -134,6 +145,7 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
         );
     f.render_widget(input, chunks[2]);
 
+    // Position the terminal cursor correctly when in Insert mode.
     if let Mode::Insert = app.mode {
         f.set_cursor_position(ratatui::layout::Position::new(
             chunks[2].x + 1 + cursor_pos as u16,
@@ -141,7 +153,7 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
         ));
     }
 
-    // Status bar
+    // Render the modern pill-style status bar.
     let (mode_str, mode_style) = match app.mode {
         Mode::Normal => (
             " NORMAL ",
@@ -159,16 +171,17 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
         ),
     };
 
-    let status_msg = app.status_message.as_deref().unwrap_or_else(|| {
-        match app.mode {
-            Mode::Normal => " navigation | i: edit | :w: save | :q: quit ",
-            Mode::Insert => " Esc: back to normal | Enter: commit ",
-        }
+    let status_msg = app.status_message.as_deref().unwrap_or_else(|| match app.mode {
+        Mode::Normal => " navigation | i: edit | :w: save | :q: quit ",
+        Mode::Insert => " Esc: back to normal | Enter: commit ",
     });
 
     let status_line = Line::from(vec![
         Span::styled(mode_str, mode_style),
-        Span::styled(format!(" {} ", status_msg), Style::default().bg(theme.surface0()).fg(theme.text())),
+        Span::styled(
+            format!(" {} ", status_msg),
+            Style::default().bg(theme.surface0()).fg(theme.text()),
+        ),
     ]);
 
     let status = Paragraph::new(status_line).style(Style::default().bg(theme.surface0()));