<!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>

  <link rel="stylesheet" href="../assets//normalize.css">

  <style>
    body{
      width: 100vw;
      height: 100vh;
      background-image: url("../public/images/1.png");
      background-position: center center;
      background-size: cover;
      background-repeat: no-repeat;
    }
    .box{
      width: 300px;
      height: 300px;
      margin: 0 auto;
      // 必须加透明背景
      background-color: rgba(255, 255, 255, 0.4);
      // backdrop-filter添加背景模糊，blur为高斯模糊滤镜
      backdrop-filter: blur(20px);
    }
  </style>
</head>
<body>
  <div class="box"></div>
</body>
</html>

效果如下：

51df8h153asd4gfd8h

Q.E.D.

一个二次元web开发咸鱼