# Introduction to Cascading Style Sheets (CSS)
## Week 4(Blockfuse Labs Cohort IV)
## Introduction to Cascading Style Sheets (CSS)
Cascading Style Sheets (CSS) is a stylesheet language used to control the appearance and layout of web pages. While HTML is responsible for the structure of a webpage, CSS is used to make that structure look good.
In simple terms:
HTML = structure
CSS = design
What CSS Is Used For
CSS allows you to:
Change text colors and fonts
Set background colors and images
Control spacing and alignment
Create layouts (columns, grids, flexible designs)
Make websites responsive across different screen sizes
Without CSS, websites would look plain and unorganized.
## How CSS Works
CSS works by selecting HTML elements and applying styles to them.
A basic CSS rule looks like this:
```
p {
color: blue;
font-size: 16px;
}
```
p → selector (targets all paragraph elements)
color and font-size → properties
blue and 16px → values
Ways to Add CSS to HTML
There are three main ways to apply CSS:
### 1. Inline CSS
Applied directly inside an HTML tag.
```
<p style="color: red;">Hello World</p>
```
### 2. Internal CSS
Written inside a <style> tag in the HTML <head>.
<style>
p {
color: green;
}
</style>
### 3. External CSS (Most recommended)
Written in a separate .css file and linked to HTML.
<link rel="stylesheet" href="style.css">
This method keeps code clean and reusable.
### Why CSS Is Important
Improves user experience
Makes websites visually appealing
Helps separate content from design
Essential for modern web development
### Conclusion
CSS is a core web technology that works alongside HTML and JavaScript. Learning CSS is a crucial step in becoming a front-end or full-stack developer.