CSS过渡持续时间属性

使用 transition-duration属性设置过渡持续时间

示例

<!DOCTYPE html>
<html>
   <head>
      <style>
         div {
            width: 150px;
            height: 150px;
            background: blue;
            transition-property: height;
            transition-duration: 2s;
         }
         div:hover {
            height: 200px;
         }
      </style>
   </head>
   <body>
      <h1>Heading One</h1>
      <p>Hover over the below box to change its height.</p>
      <div></div>
   </body>
</html>