CSS stands for "Cascading Style Sheets." It is a language used to describe the appearance and formatting of a document written in HTML or XML. CSS controls the layout of web pages, including design, colors, fonts and placement of elements, making it possible to separate content from presentation.
How does CSS work?
CSS works by applying style rules to HTML elements. These rules can be defined in external stylesheets, internal stylesheets or inline. Here is a basic overview of how CSS works:
- Selectors: CSS uses selectors to target specific HTML elements. For example, the selector
ptargets all<p>(paragraph) elements. - Properties and values: Each style rule consists of a property and a value. For example, the rule
color: red;will set the text color to red. - Cascading: If multiple rules apply to the same element, the cascading rules determine which style to apply based on specific criteria such as specificity and importance.
Example of CSS
Here is a simple example of how CSS can be used to style an HTML page:
HTML:
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
<h1>Welcome to my website</h1>
<p>This is a simple CSS-styled page.</p>
</body>
</html>
CSS (style.css):
h1 {
color: blue;
font-family: Arial, sans-serif;
text-align: center;
}
p {
color: green;
font-size: 14px;
}
Advantages of using CSS
CSS offers many advantages, including:
- Separation of content and style: By separating HTML (content) from CSS (presentation), web design becomes more organized and easier to maintain.
- Reusability: Style rules can be reused across multiple pages, saving time and reducing redundancy.
- Improved control: CSS gives fine control over layout and design, enabling the creation of complex and sophisticated web designs.
- Responsive design: CSS makes it possible to create designs that adapt to different screen sizes and devices, enhancing user experience.
Applications
CSS is widely used in web development to style and design web pages. Here are some common applications:
- Layout: Determines the placement of elements on a page, including grids, flexbox and positioning.
- Typography: Specifies fonts, font sizes, colors and text alignment.
- Colors and backgrounds: Specifies background colors, images and other visual effects.
- Animations and transitions: Adds dynamic effects and animations to web content.
CSS is a fundamental technology in web development that makes it possible to create attractive, user-friendly and responsive-designed websites.