1. Attribute introduction: Add the style attribute in the tag, only applicable to the current tag 2. tag introduction: Use the <style> tag in the current page to introduce, only applicable to Current document</p> <p> 3.<link> tag introduction: refers to an external CSS style sheet file, applicable to all documents that introduce the file</p> <p> The three methods have their own purposes, use them according to your needs ,However, unless there are special circumstances, use external style sheets as much as possible</p><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false"><!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <link rel="stylesheet" type="text/css" href="./css/demo.css"> <link rel="stylesheet" type="text/css" href="./css/demo.php"> <title>css样式引入的三个级别</title> <style type="text/css"> h3 { background-color: lightcyan; color: blue; } 这是一个悲伤的故事
