CSS

Develop a comprehensive flashcard study system using HTML5, CSS3, and JavaScript. Create an intuitive interface for card creation and review. Implement spaced repetition algorithm for optimized learning. Add support for text, images, and audio on cards. Include card categorization with decks and tags. Implement study sessions with performance tracking. Add self-assessment with confidence levels. Create statistics dashboard showing learning progress. Support import/export of card decks in standard formats. Implement keyboard shortcuts for efficient review. Add dark mode and customizable themes.

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 comprehensive budget tracking application using HTML5, CSS3, and JavaScript. Create an intuitive dashboard showing income, expenses, savings, and budget status. Implement transaction management with categories, tags, and recurring transactions. Add interactive charts and graphs for expense analysis by category and time period. Include budget goal setting with progress tracking and alerts. Support multiple accounts and transfer between accounts. Implement receipt scanning and storage using the device camera. Add export functionality for reports in CSV and PDF formats. Create a responsive design with mobile-first approach. Include data backup and restore functionality. Add forecasting features to predict future financial status based on current trends.

Create a recipe finder application using HTML5, CSS3, JavaScript and a food API. Build a visually appealing interface with food photography and intuitive navigation. Implement advanced search with filtering by ingredients, cuisine, diet restrictions, and preparation time. Add user ratings and reviews with star system. Include detailed nutritional information with visual indicators for calories, macros, and allergens. Support recipe saving and categorization into collections. Implement a meal planning calendar with drag-and-drop functionality. Add automatic serving size adjustment with quantity recalculation. Include cooking mode with step-by-step instructions and timers. Support offline access to saved recipes. Add social sharing functionality for favorite recipes.

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.

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.

Develop a web-based music player using HTML5, CSS3, and JavaScript with the Web Audio API. Create a modern interface with album art display and visualizations. Implement playlist management with drag-and-drop reordering. Add audio controls including play/pause, skip, seek, volume, and playback speed. Include shuffle and repeat modes with visual indicators. Support multiple audio formats with fallbacks. Implement a 10-band equalizer with presets. Add metadata extraction and display from audio files. Create a responsive design that works on all devices. Include keyboard shortcuts for playback control. Support background playback with media session API integration.

Build a mindfulness meditation timer using HTML5, CSS3, and JavaScript. Create a serene, distraction-free interface with nature-inspired design. Implement customizable meditation sessions with preparation, meditation, and rest intervals. Add ambient sound options including nature sounds, binaural beats, and white noise. Include guided meditation with customizable voice prompts. Implement interval bells with volume control and sound selection. Add session history and statistics tracking. Create visual breathing guides with animations. Support offline usage as a PWA. Include dark mode and multiple themes. Add session scheduling with reminders.

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.

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.

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.

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.

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 an immersive multiplayer airplane combat game using Three.js, HTML5, CSS3, and JavaScript with WebSocket for real-time networking. Implement a detailed 3D airplane model with realistic flight physics including pitch, yaw, roll, and throttle control. Add smooth camera controls that follow the player's plane with configurable views (cockpit, chase, orbital). Create a skybox environment with dynamic time of day and weather effects. Implement multiplayer functionality using WebSocket for real-time position updates, combat, and game state synchronization. Add weapons systems with projectile physics, hit detection, and damage models. Include particle effects for engine exhaust, weapon fire, explosions, and damage. Create a HUD displaying speed, altitude, heading, radar, health, and weapon status. Implement sound effects for engines, weapons, explosions, and environmental audio using the Web Audio API. Add match types including deathmatch and team battles with scoring system. Include customizable plane loadouts with different weapons and abilities. Create a lobby system for match creation and team assignment. Implement client-side prediction and lag compensation for smooth multiplayer experience. Add mini-map showing player positions and objectives. Include replay system for match playback and highlight creation. Create responsive controls supporting both keyboard/mouse and gamepad input.

Create a responsive todo app with HTML5, CSS3 and vanilla JavaScript. The app should have a modern, clean UI using CSS Grid/Flexbox with intuitive controls. Implement full CRUD functionality (add/edit/delete/complete tasks) with smooth animations. Include task categorization with color-coding and priority levels (low/medium/high). Add due dates with a date-picker component and reminder notifications. Use localStorage for data persistence between sessions. Implement search functionality with filters for status, category, and date range. Add drag and drop reordering of tasks using the HTML5 Drag and Drop API. Ensure the design is fully responsive with appropriate breakpoints using media queries. Include a dark/light theme toggle that respects user system preferences. Add subtle micro-interactions and transitions for better UX.

Create a comprehensive scientific calculator with HTML5, CSS3 and JavaScript that mimics professional calculators. Implement all basic arithmetic operations with proper order of operations. Include advanced scientific functions (trigonometric, logarithmic, exponential, statistical) with degree/radian toggle. Add memory operations (M+, M-, MR, MC) with visual indicators. Maintain a scrollable calculation history log that can be cleared or saved. Implement full keyboard support with appropriate key mappings and shortcuts. Add robust error handling for division by zero, invalid operations, and overflow conditions with helpful error messages. Create a responsive design that transforms between standard and scientific layouts based on screen size or orientation. Include multiple theme options (classic, modern, high contrast). Add optional sound feedback for button presses with volume control. Implement copy/paste functionality for results and expressions.

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 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.