what is css tag

CSS tag is a markup language used to define styles in HTML documents, which is called Cascading Style Sheets. It can control the appearance, typesetting, layout and other aspects of each element on the HTML page, and is used to enhance the readability, accessibility and user experience of the website.

In the actual development process, CSS tags are often used together with HTML tags. Their combination can help developers better control the layout and appearance of the site, thereby effectively improving the usability and attractiveness of the page.

CSS tags are divided into many types, some of the more commonly used tags are as follows:

1. font-size (font size): used to control the font size of text. Text size can be set by specifying pixel size or relative size.
2. color (text color): used to control text color. Colors can be set by specifying hexadecimal color values ​​or RGB color values.
3. text-align (text alignment): used to control the alignment of text in elements. You can set left alignment, right alignment, center alignment, etc.
4. background-color (background color): used to set the background color of the element. Colors can be set by specifying hexadecimal color values ​​or RGB color values.
5. border (border): used to set the border style, thickness and color of the element. You can specify the border style as solid line, dashed line, double solid line, etc.
6. margin (margin): used to set the size of the blank area around the element. You can specify margin values ​​in four directions: top, bottom, left, and right.
7. padding (padding): used to set the size of the blank area inside the element. You can specify padding values ​​in four directions: top, bottom, left, and right.
8. display (display mode): used to control how elements are displayed on the page. Elements can be set to block-level elements, row-level elements, table elements, etc.

In addition to the above common CSS tags, there are many other tags that can be used to control element styles. Some common combination tags are as follows:

1. hover: Used to style the element when the mouse is hovering.
2. visited: used to set the style of the element after it is visited.
3. active: Used to set the style of the element when it is activated or clicked.

Overall, CSS tags play an important role in web development. Through reasonable use of CSS tags, various effects can be achieved, such as creating beautiful page layouts, improving website usability and access speed, etc. In the actual development process, developers need to be familiar with the usage of various CSS tags in order to create more beautiful and practical website pages.

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