CSS Cheat Sheet
Complete CSS reference with live visual examples. Master selectors, layout, styling, animations, and responsive design with interactive demonstrations.
📚 Quick Navigation
🎨 What is CSS?
CSS (Cascading Style Sheets) is a powerful styling language created by Håkon Wium Lie in 1996. CSS controls the presentation, layout, and visual appearance of web documents written in HTML or XML. It separates content from presentation, allowing developers to maintain clean, semantic HTML while creating beautiful, responsive designs. CSS has evolved significantly from its early days, now supporting animations, complex layouts, and modern design patterns.
🚀 Core Capabilities
- ✓ Layout Control: Flexbox, Grid, and positioning for complex layouts
- ✓ Visual Styling: Colors, typography, spacing, and effects
- ✓ Responsive Design: Media queries for multi-device support
- ✓ Animations: Transitions and keyframe animations
- ✓ Accessibility: Screen reader and keyboard navigation support
💡 Why CSS Matters
- • Separation of Concerns: Keep content and styling separate
- • Maintainability: Change designs without touching HTML
- • Performance: Cached stylesheets improve load times
- • Consistency: Unified styling across entire websites
- • Responsive Web: Adapt to any screen size or device
🎯 CSS Syntax & Structure
Basic Syntax
selector { property: value; } h1 { color: blue; font-size: 2rem; }CSS Structure
CSS rules consist of selectors that target HTML elements and declarations that define how those elements should be styled.
CSS Best Practices
📱 Mobile First
Design for mobile devices first, then enhance for larger screens
🎯 Use Semantic Classes
Name classes based on purpose, not appearance (.button vs .red-box)
⚡ Optimize Performance
Minimize CSS, use efficient selectors, avoid deep nesting
🔧 Use Modern Layout
Embrace Flexbox and Grid instead of floats and tables
♿ Ensure Accessibility
Maintain color contrast, focus states, and screen reader support
🔄 Plan for Maintenance
Organize CSS logically, document complex selectors, use variables
CSS cheat sheet with visual examples and modern best practices