Borders, Rounded Corners and Shadows

What Is It?

Borders mark edges, border-radius rounds corners, and box-shadow adds a visual shadow without reserving layout space.

Properties, Tags and Attributes Explained

• border: Shorthand for width, style, and color. A border needs a visible style such as solid.
• border-radius: Rounds corners; 50% creates a circle when width and height are equal.
• box-shadow: Sets horizontal offset, vertical offset, blur, optional spread, and color.

Each example is a complete HTML page. The CSS is inside the head's style element. Use Try in new tab to edit the CSS or HTML, run your changes, and reset the example.

Example 1: Card outline

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Borders, Rounded Corners and Shadows</title>
  <style>
    .card { border: 1px solid #94a3b8; border-radius: 12px; padding: 20px; }
  </style>
</head>
<body>
  <div class="card"><h2>Starter plan</h2><p>A clear, simple card.</p></div>
</body>
</html>

What you see: The card has a thin outline and softly rounded corners.

Example 2: Circular badge

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Borders, Rounded Corners and Shadows</title>
  <style>
    .badge { width: 80px; height: 80px; border-radius: 50%; display: grid; place-items: center; background: #dbeafe; box-shadow: 0 6px 12px #0f172a33; }
  </style>
</head>
<body>
  <div class="badge">CSS</div>
</body>
</html>

What you see: An equal-width and equal-height box becomes a circle with a shadow.

When and Where to Use It

Use borders to separate regions and subtle shadows to suggest elevation for cards or menus.

Common Mistake or Useful Tip

A shadow does not push nearby elements away. Leave enough room so it is not clipped.

Try It Yourself

Change the shadow blur from 12px to 0 and compare its edge.