How to reference css files

With the continuous development of web development technology, web design requirements are getting higher and higher. As CSS files are an important foundation for web design, how to correctly reference CSS files has become a must-learn skill in web development. This article will introduce how to reference CSS files to help beginners better master this skill.

1. What is a CSS file?

CSS, the full name of Cascading Style Sheets, is a style sheet language used to specify how documents such as HTML, XHTML and XML are presented. By using CSS, the structure and content of the web page can be separated, which separates the content and style of the web page and improves the readability and maintainability of the web page.

2. How to create CSS files?

CSS files can be created in two ways: handwritten or using a CSS editing tool.

1. Handwritten CSS files

Handwritten CSS files need to be written in a text editor or development tool, and the file format is ".css". The specific steps are as follows:

(1) Create a new text file in "*.css" format in any text editor, such as "style.css".

(2) Write CSS style code in a text file. CSS style code includes style rules, attributes and attribute values. For example:

p {
   color: red;
   text-align: center;
}

(3) Link CSS files in HTML documents. Here's how to link CSS files.

2. Use CSS editing tools

Compared with handwriting CSS files, using professional CSS editing tools can improve development efficiency and code quality. Common CSS editing tools include Dreamweaver, Sublime Text, Visual Studio Code, etc.

3. How to reference CSS files?

There are two main ways to reference CSS files: internal style sheets and external style sheets.

1. Internal style sheet

The internal style sheet embeds CSS style code directly into the HTML document. The specific steps are as follows:

(1) Insert the style tag <style></style> in the header tag.

   <style>
      p {
         color: red;
         text-align: center;
      }
   </style>

(2) Write CSS style code in the style tag. For example:

<style>
   p {
      color: red;
      text-align: center;
   }
</style>

Advantages: It is suitable for modifying the style of a small number of pages and is easy to use.

Disadvantages: It is difficult to maintain, increases code complexity, and also reduces browser caching effect.

2. External style sheet

An external style sheet writes the CSS code in a separate file and then references it through a link in the HTML document. The specific steps are as follows:

(1) Create a CSS file and write CSS style code.

(2) Insert the link tag <link> in the head tag, pointing to the CSS file.

   <link>

Advantages: Styles are separated from page content, making file maintenance easy.

Disadvantages: Additional CSS files need to be loaded, which increases HTTP requests compared to the internal style sheet.

4. Summary

Through the introduction of this article, we have learned the creation and reference of CSS files, and understood the characteristics of internal style sheets and external style sheets. In web development, correctly referencing CSS files is a very basic skill. I hope this article can help beginners better master this skill and further improve the level of web design and development.

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