what does css mean

CSS (Cascading Style Sheets) means "cascading style sheets" and is a language that controls the appearance of HTML and XML web pages. This language is a series of standards defined by the W3C. It provides a way for website designers to precisely control the appearance of various elements in a web page, such as font size, color, spacing, borders, background images, etc. wait.

CSS was originally released by the World Wide Web Consortium (W3C) in 1996. Web design at that time could only control page layout and format based on HTML, which made the appearance of the web page very single and limited. The introduction of CSS solved this problem.

The main function of CSS is to add styles to web pages. Before using CSS, web developers had to style HTML elements like this:

Hello World!

After using CSS, the document structure and style can be separated to make HTML more concise and readable:

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

The above code will apply the same style to all paragraph tags (

). In this case, if you need to adjust the website style, you only need to modify the CSS file without changing the HTML file.

The core idea of ​​CSS is "Cascading". This means that styles can be overridden by multiple rules or combined. When a tag has multiple CSS rules applied to it, the priority of the rules will come into play. The order of priority is: inline style > ID selector > class selector > element selector. If there are equal priorities, the decision will be based on the last-come-first-served principle.

For example:

Hello World!

The above code will The font color will be set to blue because inline styles have higher priority.

CSS also supports almost all web page style settings such as fonts, pictures, shadows, animations, etc. It enables web designers to create more beautiful, vivid and interesting web pages.

In addition to the above-mentioned limitations on the appearance of web pages, CSS has other benefits. A style sheet can be applied to multiple pages to maintain consistency across the entire website. CSS also makes it very easy to provide different styles for different devices, which is called responsive design.

In short, CSS is a very important web design language. It provides web designers with a method of organizational structure and style control, so that web pages can present different styles and appearances.

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