css 下划线动态-526互联

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
      h1 span {
        background: linear-gradient(to right, #ec695c, #61c454) no-repeat right bottom;
        background-size: 0 2px;
        transition: background-size 1300ms;
      }
      h1 span:hover {
        background-position-x: left;
        background-size: 100% 2px;
      }
    </style>
  </head>
  <body>
    <h1>
      <span>爱你一万年，爱你永不会改变</span>
    </h1>
  </body>
</html>