CSS Responsive Layout

Responsive Images

Basic Responsive Image

img {
  max-width: 100%;
  height: auto;
}

Responsive Background Image

.banner {
  background-image: url("desktop-bg.jpg");
  background-size: cover;
  background-position: center;
}

@media (max-width: 768px) {
  .banner {
    background-image: url("mobile-bg.jpg");
  }
}

Responsive Tables

Tables can overflow on small screens. Use overflow-x: auto for horizontal scrolling:

Example

<style>
.table-wrapper {
  overflow-x: auto;
}
table {
  width: 100%;
  border-collapse: collapse;
  min-width: 600px;
}
th, td {
  border: 1px solid #ddd;
  padding: 8px;
  text-align: left;
}
</style>
<div class="table-wrapper">
  <table>
    <tr><th>Name</th><th>Email</th><th>Phone</th><th>Address</th><th>City</th></tr>
    <tr><td>John</td><td>john@email.com</td><td>123-456-7890</td><td>123 Main St</td><td>New York</td></tr>
  </table>
</div>

Show/Hide Elements

Use media queries to show/hide elements at different breakpoints:

Example

<style>
.desktop-only {
  display: none;
}
.mobile-only {
  display: block;
}

@media (min-width: 768px) {
  .desktop-only {
    display: block;
  }
  .mobile-only {
    display: none;
  }
}
</style>
<div class="mobile-only">📱 Mobile only content</div>
<div class="desktop-only">🖥️ Desktop only content</div>

Testing Responsive Layouts

1. Browser resize: Drag browser window edges
2. Chrome DevTools: F12 → Toggle device toolbar (Ctrl+Shift+M)
3. Real devices: Test on actual phones/tablets when possible

❓ FAQ

📖 Summary

• Responsive layout's core is "flexible adaptation"
• Through flexible grids (% / fr), flexible images (max-width), and media queries (@media), you can build pages that perform well on all screens
• In practice, "mobile-first" is recommended: write mobile styles first, then use min-width to progressively add styles for tablet and desktop

📝 Exercises

1. Create a "responsive personal blog" page with header navigation, article list, sidebar recommendations, and footer copyright. Requirements: mobile single column, tablet two columns, desktop three columns + fixed sidebar.
2. Use min-width breakpoints to change a card grid from 1 column to 4 columns, observing at each breakpoint.
3. Create a responsive table page where tables can scroll horizontally on small screens (using overflow-x: auto).