CSS Introduction

CSS stands for Cascading Style Sheets.

HTML creates the structure of a website.
CSS decides how that structure looks.

Without CSS:

• text is black
• background is white
• everything looks plain

With CSS:

• colors appear
• layouts form
• spacing feels natural
• websites look professional

Real world comparison

Think of HTML as a house structure:

• walls
• doors
• rooms

CSS is:

• paint color
• furniture
• curtains
• lighting

The house exists without decoration, but nobody wants to live in it.

What CSS controls

CSS controls:

• colors
• fonts
• spacing
• alignment
• layout
• responsiveness
• animations

Very first example

Try editing the code below to see how HTML and CSS work together:

<p>Hello World</p>

p {
  color: blue;
  font-size: 20px;
}

The text becomes blue and larger, just like on a real website. Try changing the color or font-size in the CSS tab above!

Why CSS is required today

Modern users expect:

• clean design
• mobile support
• smooth UI

Without CSS, a website looks broken and untrustworthy.

Remember

• HTML builds structure
• CSS makes it beautiful
• Every professional website depends on CSS