<!DOCTYPE html>
<html lang="zh-CN">

<head>

  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">

  <title>33 - 滚雪球加载 (HTML+CSS)</title>

  <link rel="stylesheet" href="./css/index.css">

</head>

<body>

  <!-- 父盒子 -->
  <div class="box">
    <!-- 圆环 -->
    <div class="ring"></div>

    <!-- 雪球 -->
    <div class="ball">
      <!-- 雪球纹理 -->
      <div class="texture"></div>
      <!-- 阴影 -->
      <div clas