What is a css file?

The css file is a text file written using the grammatical rules specified by CSS, with the extension ".css"; it is a file used in conjunction with the html language to create web pages. Its main function is to control The layout of the HTML document simply means controlling the display appearance of the web page.

The operating environment of this tutorial: Windows 7 system, CSS3&&HTML5 version, Dell G3 computer.

css files are with .css as the suffix. We see that files with .css as the suffix are css files.

The CSS file itself is actually a text file, but it is written using the grammatical rules specified by CSS so that the browser can recognize it.

CSS file is a file used in conjunction with html language to create web pages. Its main function is to control the layout of html articles. Simply put, it controls the display appearance of web pages.

In addition to controlling the page layout, the css file can also well separate the html code and css code, so that the content and layout can be written independently without interfering with each other, and the organization is clearer.

CSS files can be placed in different HTML files to unify the styles of all pages of the website; furthermore, putting the CSS code into one CSS file facilitates management, reduces code and maintenance time; when modifying the CSS file, All HTML files to which this CSS file is applied will be updated without having to fetch all pages from the server and upload them after modification.

How HTML calls CSS files

1. Link type (link)

Link type uses the tag of HTML to add external Style sheet files are linked to HTML documents. This is the most commonly used method for websites on the Internet, and it is also the most practical method. This method completely separates HTML documents and CSS files, achieves a complete separation of the structure layer and the presentation layer, and enhances the scalability of the web page structure and the maintainability of CSS styles.

Syntax:

<link rel="stylesheet"  type="text/css"  href="css文件的路径" >

2. Import (@import)

Import styles Use the @import command to import external style sheets.

The import method will load the CSS file after the entire web page is loaded, so this leads to a problem. If the web page is relatively large, an unstyled page will appear first. After a flash, the web page will appear again. style. This is an inherent flaw of imports.

There are 6 ways to write the imported style:

<style type="text/css" media="screen">   
@import CSS文件路径;
@import &#39;CSS文件路径&#39;;
@import "CSS文件路径";
@import url(CSS文件路径);
@import url(&#39;CSS文件路径&#39;);
@import url("CSS文件路径");
</style>

(Learning video sharing: css video tutorial)

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