Learn CSS with Real Code Examples
Updated Nov 21, 2025
Explain
CSS uses selectors to target HTML elements and apply style rules.
It enables consistent design across multiple pages.
CSS works alongside HTML for structure and JavaScript for interactivity.
Core Features
Separation of content and presentation
Cascading and inheritance of styles
Flexible units (px, em, rem, %, vw, vh)
Layered styling via specificity and !important
Support for custom properties (CSS variables)
Basic Concepts Overview
Selectors: element, class, ID, attribute, pseudo-class
Properties: color, font-size, margin, padding, display
Values: keywords, lengths, percentages, colors, functions
Box model: content, padding, border, margin
Cascading and specificity rules
Project Structure
styles/main.css - primary stylesheet
styles/reset.css - reset browser defaults
styles/components/ - reusable component styles
styles/layout/ - page layout styles
assets/fonts/ - custom fonts for typography
Building Workflow
Write CSS rules in `.css` file
Link CSS to HTML via `<link>` or `<style>`
Test styles in browser
Use developer tools for debugging
Optimize for performance and responsiveness
Difficulty Use Cases
Beginner: simple color and font changes
Intermediate: layouts with Flexbox or Grid
Advanced: responsive design with media queries
Expert: animations, transitions, and CSS variables
Community: contribute to CSS frameworks or open standards
Comparisons
Simpler than scripting languages for styling
Complements HTML for content presentation
More flexible than inline HTML attributes
Lightweight and widely supported
Essential for modern web design
Versioning Timeline
1994 – CSS1 specification by W3C
1996 – CSS2 released
1998 – CSS2.1 updates
2011–2018 – CSS3 modules standardized
2025 – CSS continues evolving with modern features
Glossary
Selector: targets HTML elements
Property: style attribute to apply
Value: assigned value for a property
Box model: content, padding, border, margin
Media query: conditional style for viewport sizes