Styling HTML with CSS
CSS stands for Cascading Style Sheets.
CSS describes how HTML elements are to be displayed on screen, paper, or in other media. CSS saves a lot of work. It can control the layout of multiple web pages all at once.
CSS can be added to HTML elements in 3 ways:
- Inline - by using the style attribute in HTML elements
- Internal - by using a <style> element in the <head> section
- External - by using an external CSS file
Inline CSS 内联样式- 在HTML元素中使用"style" 属性
An inline CSS is used to apply a unique style to a single HTML element.
An inline CSS uses the style attribute of an HTML element.
This example sets the text color of the <h1> element to blue:
<h1 style="color:blue;">This is a Blue Heading</h1>
Internal CSS 内部样式表 -在HTML文档头部 <head> 区域使用<style> 元素 来包含CSS
An internal CSS is used to define a style for a single HTML page.
An internal CSS is defined in the <head> section of an HTML page, within a <style> element:
<!DOCTYPE html>
<html>
<head>
<style>
body {background-color: powderblue;}
h1 {color: blue;}
p {color: red;}
</style>
</head>
<body>
<h1>This is a heading</h1>
<p>This is a paragraph.</p>
</body>
</html>
External CSS 外部引用 - 使用外部 CSS 文件
An external style sheet is used to define the style for many HTML pages.
With an external style sheet, you can change the look of an entire web site, by changing one file!
To use an external style sheet, add a link to it in the <head> section of the HTML page:
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="styles.css">
</head>
<body>
<h1>This is a heading</h1>
<p>This is a paragraph.</p>
</body>
</html>
An external style sheet can be written in any text editor. The file must not contain any HTML code, and must be saved with a .css extension.
Here is how the "styles.css" looks:
body {
background-color: powderblue;
}
h1 {
color: blue;
}
p {
color: red;
}
External References
External style sheets can be referenced with a full URL or with a path relative to the current web page.
This example uses a full URL to link to a style sheet:
<link rel="stylesheet" href="https://www.w3schools.com/html/styles.css">
This example links to a style sheet located in the html folder on the current web site:
<link rel="stylesheet" href="/html/styles.css">
This example links to a style sheet located in the same folder as the current page:
<link rel="stylesheet" href="styles.css">
You can read more about file paths in the chapter HTML File Paths.
