Develop a comprehensive interactive quiz application
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
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).
Build a comprehensive health metrics calculator
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 comprehensive secure password generator
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.
Develop a comprehensive currency converter
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).