CSS

Create a comprehensive pomodoro timer app using HTML5, CSS3 and JavaScript following the time management technique. Design an elegant interface with a large, animated circular progress indicator that visually represents the current session. Allow customization of work intervals (default 25min), short breaks (default 5min), and long breaks (default 15min). Include a task list integration where users can associate pomodoro sessions with specific tasks. Add configurable sound notifications for interval transitions with volume control. Implement detailed statistics tracking daily/weekly productivity with visual charts. Use localStorage to persist settings and history between sessions. Make the app installable as a PWA with offline support and notifications. Add keyboard shortcuts for quick timer control (start/pause/reset). Include multiple theme options with customizable colors and fonts. Add a focus mode that blocks distractions during work intervals.

Develop a comprehensive interactive quiz application with HTML5, CSS3 and JavaScript. Create an engaging UI with smooth transitions between questions. Support multiple question types including multiple choice, true/false, matching, and short answer with automatic grading. Implement configurable timers per question with visual countdown. Add detailed score tracking with points based on difficulty and response time. Show a dynamic progress bar indicating completion percentage. Include a review mode to see correct/incorrect answers with explanations after quiz completion. Implement a persistent leaderboard using localStorage. Organize questions into categories with custom icons and descriptions. Support multiple difficulty levels affecting scoring and time limits. Generate a detailed results summary with performance analytics and improvement suggestions. Add social sharing functionality for results with customizable messages.

Build a professional-grade color tool with HTML5, CSS3 and JavaScript for designers and developers. Create an intuitive interface with multiple selection methods including eyedropper, color wheel, sliders, and input fields. Implement real-time conversion between color formats (RGB, RGBA, HSL, HSLA, HEX, CMYK) with copy functionality. Add a color palette generator with options for complementary, analogous, triadic, tetradic, and monochromatic schemes. Include a favorites system with named collections and export options. Implement color harmony rules visualization with interactive adjustment. Create a gradient generator supporting linear, radial, and conic gradients with multiple color stops. Add an accessibility checker for WCAG compliance with contrast ratios and colorblindness simulation. Implement one-click copy for CSS, SCSS, and SVG code snippets. Include a color naming algorithm to suggest names for selected colors. Support exporting palettes to various formats (Adobe ASE, JSON, CSS variables, SCSS).

Create a comprehensive secure password generator using HTML5, CSS3 and JavaScript with cryptographically strong randomness. Build an intuitive interface with real-time password preview. Allow customization of password length with presets for different security levels. Include toggles for character types (uppercase, lowercase, numbers, symbols) with visual indicators. Implement an advanced strength meter showing entropy bits and estimated crack time. Add a one-click copy button with confirmation and automatic clipboard clearing. Create a password vault feature with encrypted localStorage storage. Generate multiple passwords simultaneously with batch options. Maintain a password history with generation timestamps. Calculate and display entropy using standard formulas. Offer memorable password generation options (phrase-based, pattern-based). Include export functionality with encryption options for password lists.

Create an interactive drawing application using HTML5 Canvas, CSS3, and JavaScript. Build a clean interface with intuitive tool selection. Implement multiple drawing tools including brush, pencil, shapes, text, and eraser. Add color selection with recent colors, color picker, and palettes. Include layer support with opacity and blend mode options. Implement undo/redo functionality with history states. Add image import and export in multiple formats (PNG, JPG, SVG). Support canvas resizing and rotation. Implement zoom and pan navigation. Add selection tools with move, resize, and transform capabilities. Include keyboard shortcuts for common actions.

Develop a comprehensive currency converter using HTML5, CSS3, JavaScript and a reliable Exchange Rate API. Create a clean, intuitive interface with prominent input fields and currency selectors. Implement real-time exchange rates with timestamp indicators showing data freshness. Support 170+ global currencies including crypto with appropriate symbols and formatting. Maintain a conversion history log with timestamps and rate information. Allow users to bookmark favorite currency pairs for quick access. Generate interactive historical rate charts with customizable date ranges. Implement offline functionality using cached exchange rates with clear staleness indicators. Add a built-in calculator for complex conversions and arithmetic operations. Create rate alerts for target exchange rates with optional notifications. Include side-by-side comparison of different provider rates when available. Support printing and exporting conversion results in multiple formats (PDF, CSV, JSON).

Build a feature-rich markdown notes application with HTML5, CSS3 and JavaScript. Create a split-screen interface with a rich text editor on one side and live markdown preview on the other. Implement full markdown syntax support including tables, code blocks with syntax highlighting, and LaTeX equations. Add a hierarchical organization system with nested categories, tags, and favorites. Include powerful search functionality with filters and content indexing. Use localStorage with optional export/import for data backup. Support exporting notes to PDF, HTML, and markdown formats. Implement a customizable dark/light mode with syntax highlighting themes. Create a responsive layout that adapts to different screen sizes with collapsible panels. Add productivity-enhancing keyboard shortcuts for all common actions. Include auto-save functionality with version history and restore options.

Create a client-side file encryption tool using HTML5, CSS3, and JavaScript with the Web Crypto API. Build a drag-and-drop interface for file selection with progress indicators. Implement AES-256-GCM encryption with secure key derivation from passwords (PBKDF2). Add support for encrypting multiple files simultaneously with batch processing. Include password strength enforcement with entropy calculation. Generate downloadable encrypted files with custom file extension. Create a decryption interface with password verification. Implement secure memory handling with automatic clearing of sensitive data. Add detailed logs of encryption operations without storing sensitive information. Include export/import of encryption keys with proper security warnings. Support for large files using streaming encryption and chunked processing.

Build a developer-focused code snippet manager using HTML5, CSS3, and JavaScript. Create a clean IDE-like interface with syntax highlighting for 30+ programming languages. Implement a tagging and categorization system for organizing snippets. Add a powerful search function with support for regex and filtering by language/tags. Include code editing with line numbers, indentation guides, and bracket matching. Support public/private visibility settings for each snippet. Implement export/import functionality in JSON and Gist formats. Add keyboard shortcuts for common operations. Create a responsive design that works well on all devices. Include automatic saving with version history. Add copy-to-clipboard functionality with syntax formatting preservation.

Build a Kanban project management board using HTML5, CSS3, and JavaScript. Create a flexible board layout with customizable columns (To Do, In Progress, Done, etc.). Implement drag-and-drop card movement between columns with smooth animations. Add card creation with rich text formatting, labels, due dates, and priority levels. Include user assignment with avatars and filtering by assignee. Implement card comments and activity history. Add board customization with column reordering and color themes. Support multiple boards with quick switching. Implement data persistence using localStorage with export/import functionality. Create a responsive design that adapts to different screen sizes. Add keyboard shortcuts for common actions.

Build a comprehensive weather dashboard using HTML5, CSS3, JavaScript and the OpenWeatherMap API. Create a visually appealing interface showing current weather conditions with appropriate icons and background changes based on weather/time of day. Display a detailed 5-day forecast with expandable hourly breakdown for each day. Implement location search with autocomplete and history, supporting both city names and coordinates. Add geolocation support to automatically detect user's location. Include toggles for temperature units (°C/°F) and time formats. Display severe weather alerts with priority highlighting. Show detailed meteorological data including wind speed/direction, humidity, pressure, UV index, and air quality when available. Include sunrise/sunset times with visual indicators. Create a fully responsive layout using CSS Grid that adapts to all device sizes with appropriate information density.

Create a habit tracking application using HTML5, CSS3, and JavaScript. Build a clean interface showing daily, weekly, and monthly views. Implement habit creation with frequency, reminders, and goals. Add streak tracking with visual indicators and milestone celebrations. Include detailed statistics and progress graphs. Support habit categories and tags for organization. Implement calendar integration for scheduling. Add data visualization showing patterns and trends. Create a responsive design for all devices. Include data export and backup functionality. Add gamification elements with achievements and rewards.

Develop a web-based image editor using HTML5 Canvas, CSS3, and JavaScript. Create a professional interface with tool panels and preview area. Implement basic adjustments including brightness, contrast, saturation, and sharpness. Add filters with customizable parameters and previews. Include cropping and resizing with aspect ratio controls. Implement text overlay with font selection and styling. Add shape drawing tools with fill and stroke options. Include layer management with blending modes. Support image export in multiple formats and qualities. Create a responsive design that adapts to screen size. Add undo/redo functionality with history states.

Build a comprehensive text analysis tool using HTML5, CSS3, and JavaScript. Create a clean interface with text input area and results dashboard. Implement word count, character count, and reading time estimation. Add readability scoring using multiple algorithms (Flesch-Kincaid, SMOG, Coleman-Liau). Include keyword density analysis with visualization. Implement sentiment analysis with emotional tone detection. Add grammar and spelling checking with suggestions. Include text comparison functionality for similarity detection. Support multiple languages with automatic detection. Add export functionality for analysis reports. Implement text formatting and cleaning tools.

Create an interactive Sudoku game using HTML5, CSS3, and JavaScript. Build a clean, accessible game board with intuitive controls. Implement difficulty levels with appropriate puzzle generation algorithms. Add hint system with multiple levels of assistance. Include note-taking functionality for candidate numbers. Implement timer with pause and resume. Add error checking with optional immediate feedback. Include game saving and loading with multiple slots. Create statistics tracking for wins, times, and difficulty levels. Add printable puzzle generation. Implement keyboard controls and accessibility features.

Develop a feature-rich chess game using HTML5, CSS3, and JavaScript. Create a realistic chessboard with proper piece rendering. Implement standard chess rules with move validation. Add move highlighting and piece movement animation. Include game clock with multiple time control options. Implement notation recording with PGN export. Add game analysis with move evaluation. Include AI opponent with adjustable difficulty levels. Support online play with WebRTC or WebSocket. Add opening book and common patterns recognition. Implement tournament mode with brackets and scoring.

Build a URL shortening service frontend using HTML5, CSS3, JavaScript and a backend API. Create a clean interface with prominent input field. Implement URL validation and sanitization. Add QR code generation for shortened URLs. Include click tracking and analytics dashboard. Support custom alias creation for URLs. Implement expiration date setting for links. Add password protection option for sensitive URLs. Include copy-to-clipboard functionality with confirmation. Create a responsive design for all devices. Add history of shortened URLs with search and filtering.

Build an interactive typing speed test using HTML5, CSS3, and JavaScript. Create a clean interface with text display and input area. Implement WPM and accuracy calculation in real-time. Add difficulty levels with appropriate text selection. Include error highlighting and correction tracking. Implement test history with performance graphs. Add custom test creation with text import. Include virtual keyboard display showing keypresses. Support multiple languages and keyboard layouts. Create a responsive design for all devices. Add competition mode with leaderboards.

Develop a memory matching card game using HTML5, CSS3, and JavaScript. Create visually appealing card designs with flip animations. Implement difficulty levels with varying grid sizes and card counts. Add timer and move counter for scoring. Include sound effects for card flips and matches. Implement leaderboard with score persistence. Add theme selection with different card designs. Include multiplayer mode for competitive play. Create responsive layout that adapts to screen size. Add accessibility features for keyboard navigation. Implement progressive difficulty increase during gameplay.

Create an exciting 3D racing game using Three.js and JavaScript. Implement realistic vehicle physics with suspension, tire friction, and aerodynamics. Create detailed car models with customizable paint and upgrades. Design multiple race tracks with varying terrain and obstacles. Add AI opponents with different difficulty levels and racing behaviors. Implement a split-screen multiplayer mode for local racing. Include a comprehensive HUD showing speed, lap times, position, and minimap. Create particle effects for tire smoke, engine effects, and weather. Add dynamic day/night cycle with realistic lighting. Implement race modes including time trial, championship, and elimination. Include replay system with multiple camera angles.

Develop a first-person shooter game using Three.js and JavaScript. Create detailed weapon models with realistic animations and effects. Implement precise hit detection and damage systems. Design multiple game levels with various environments and objectives. Add AI enemies with pathfinding and combat behaviors. Create particle effects for muzzle flashes, impacts, and explosions. Implement multiplayer mode with team-based objectives. Include weapon pickup and inventory system. Add sound effects for weapons, footsteps, and environment. Create detailed scoring and statistics tracking. Implement replay system for kill cams and match highlights.

Build an immersive 3D space exploration game using Three.js and JavaScript. Create a vast universe with procedurally generated planets, stars, and nebulae. Implement realistic spacecraft controls with Newtonian physics. Add detailed planet surfaces with terrain generation and atmospheric effects. Create space stations and outposts for trading and missions. Implement resource collection and cargo management systems. Add alien species with unique behaviors and interactions. Create wormhole travel effects between star systems. Include detailed ship customization and upgrade system. Implement mining and combat mechanics with weapon effects. Add mission system with story elements and objectives.

Build a comprehensive health metrics calculator with HTML5, CSS3 and JavaScript based on medical standards. Create a clean, accessible interface with step-by-step input forms. Implement accurate BMI calculation with visual classification scale and health risk assessment. Add body fat percentage calculator using multiple methods (Navy, Jackson-Pollock, BIA simulation). Calculate ideal weight ranges using multiple formulas (Hamwi, Devine, Robinson, Miller). Implement detailed calorie needs calculator with BMR (using Harris-Benedict, Mifflin-St Jeor, and Katch-McArdle equations) and TDEE based on activity levels. Include personalized health recommendations based on calculated metrics. Support both metric and imperial units with seamless conversion. Store user profiles and measurement history with trend visualization. Generate interactive progress charts showing changes over time. Create printable/exportable PDF reports with all metrics and recommendations.

Create a web-based PDF viewer using HTML5, CSS3, JavaScript and PDF.js. Build a clean interface with intuitive navigation controls. Implement page navigation with thumbnails and outline view. Add text search with result highlighting. Include zoom and fit-to-width/height controls. Implement text selection and copying. Add annotation tools including highlights, notes, and drawing. Support document rotation and presentation mode. Include print functionality with options. Create a responsive design that works on all devices. Add document properties and metadata display.