CSS, or Cascading Style Sheets, is the part of web development that controls a webpage’s visual appearance, including colors, fonts, spacing, and layout. The term “cascading” refers to how styles are prioritized; for example, inline styles override external styles, and specific selectors like #header take precedence over general ones like div. CSS is essential because without it, websites would appear plain, lacking layout, visual appeal, or responsiveness. It enables customization of fonts, arrangement of elements into grids, mobile optimization, and addition of animations. CSS works with HTML through selectors that target elements, such as p or .button, followed by declarations defining properties like color or padding. CSS can be applied inline, internally within a style block, or externally via a linked .css file, with external stylesheets being the most common due to their reusability and ease of management.
CSS stands for Cascading Style Sheets. It's the part of web development that handles how a webpage looks — things like colors, fonts, spacing, and layout. While HTML structures the content on a page, CSS styles it.
What Does "Cascading" Mean in CSS?
The word "cascading" refers to how styles are applied in a certain order and priority. If multiple rules could apply to the same element, the browser uses cascading rules to decide which one takes effect.
For example:
- Styles from external files can be overridden by styles written directly in the HTML.
- Specific selectors (like
#header) take precedence over general ones (likediv).
This hierarchy helps manage styling conflicts and maintain consistency across a site.
Why Do You Need CSS?
Without CSS, every webpage would look plain — basically black text on a white background with no layout or visual appeal. CSS lets you:
- Customize fonts and colors
- Arrange elements into columns or grids
- Make sites mobile-friendly
- Add animations and transitions
In short, CSS is what makes websites visually engaging and easy to use.
How Does CSS Work With HTML?
You connect CSS to HTML using selectors. A basic CSS rule looks like this:
p {
color: blue;
font-size: 16px;
}This rule tells the browser: "Make all paragraphs blue and 16 pixels tall." You can place CSS in three main places:
- Inline (inside an HTML tag)
- Internal (in a
<style>block in the HTML head) - External (in a
.cssfile linked to the HTML)
Most websites use external stylesheets because they're easier to manage and reuse across pages.
Basic CSS Syntax Explained
A CSS rule has two main parts:
- Selector: Which HTML element you're targeting (like
h1,.button, or#nav) - Declaration block: Inside the curly braces, where you define properties and values
Example:
.button {
background-color: green;
padding: 10px 20px;
}Here, .button is the selector, and inside are two style declarations.
That’s the core idea behind CSS — it gives you control over the appearance of your website without changing the structure of your HTML. It might seem simple at first, but there's a lot you can do once you get comfortable with it.
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