How to define css

CSS (Cascading Style Sheets) is a language used to describe the presentation style of web pages. Different from HTML (Hypertext Markup Language), it focuses more on the control of web page presentation, including text color, font, border, background color, etc.

Definition of CSS

The definition of CSS can be divided into two aspects. One aspect is what it does, and the other aspect is its basic syntax and code specifications.

Function

The main function of CSS is to control the style and layout of HTML documents to achieve better visual effects. For example, the color, font, size, etc. of text can be controlled through CSS files without having to be repeatedly defined in HTML files. At the same time, CSS can also control the position, size, border, etc. of elements.

Basic syntax and code specifications

The syntax of CSS is very simple and generally consists of three parts: selector, attribute and value. Among them, the selector refers to the HTML element that needs to be styled, and the attributes and values ​​refer to the style and style value of this element respectively.

For example, if we want to set the text color of all p tags in a page to red, we can use the following code:

p {
 color: red;
}

In the above code, p is the selection device, color is the attribute, and red is the value of this attribute. It should be noted that in CSS, attributes and values ​​are connected with a colon (:), and each attribute and value are separated with a semicolon (;).

In addition to basic selectors, attributes, and value structures, CSS also has many advanced uses, such as combinations of selectors, pseudo-classes, pseudo-elements, etc., which can be used to implement more complex styles. Effect.

Summary

CSS is a very important web design language, which allows us to more easily control the style and layout of web pages. In addition to basic syntax and conventions, we also need to understand more advanced features to be able to achieve more complex visual effects. Mastering the CSS language can make it easier for us to design web pages and improve the quality and effect of web pages.

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