HTML5 & CSS3 Master Guide

Comprehensive tutorial with examples, explanations, and interactive demos.

1. HTML5 Fundamentals

HTML5 structures web pages using semantic elements.

<header>Site Header</header>
<nav>Navigation</nav>
<main>Main Content</main>
<article>Article</article>
<section>Section</section>
<aside>Sidebar</aside>
<footer>Footer</footer>
Header
Main Area

2. Forms and Validation

<input type="email" required>
<input type="date">
<input type="range">




3. Audio and Video

<audio controls>
<video controls width="400">

HTML5 provides native media support without plugins.

4. CSS Selectors

p {}
#id {}
.class {}
div > p {}
a:hover {}
input:focus {}

5. Box Model

width + padding + border + margin
Content + Padding + Border + Margin

6. Flexbox

.container {
 display:flex;
 justify-content:center;
 align-items:center;
}
1
2
3

7. CSS Grid

display:grid;
grid-template-columns:repeat(3,1fr);
A
B
C
D

8. Responsive Design

@media (max-width:768px){
  body { font-size:14px; }
}

Use media queries to adapt layouts.

9. Transitions and Animations

Hover over me
transition: .3s;
@keyframes spin {...}

10. CSS Variables

:root {
 --accent: green;
}
button {
 background: var(--accent);
}

11. Interactive Example: Live Color Changer

Watch my background change.

12. HTML5 APIs Overview

13. Canvas Example

14. Local Storage Example

15. Modern Layout Project Example

Combine semantic HTML, Grid, Flexbox, variables, animations, forms, accessibility, and responsive design into production-quality websites.

Best Practices