css实现红绿灯 

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box{
      margin: 0 auto;
      width: 80px;
      border-radius: 40px;
      border: 3px solid #333;
      background-color: #333;
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-direction: column;
    }
    .light{
      width: 50px;
      height: 50px;
      border-radius: 50%;
      margin: 10px 0;
      background: #000;
      opacity: .1;
    }
    .red{
      background: #ff0000;
      animation: 12s red infinite;
    }
    .yellow{
      background: #ffff00;
      animation: 12s yellow infinite;
    }
    .green{
      background: #008000;
      animation: 12s green infinite;
    }
    @keyframes red{
      0%{opacity: 1;}
      30%{opacity: 1;}
      33%{opacity: .1;}
    }    
    @keyframes yellow{
      0%{opacity: .1;}
      33%{opacity: .1;}
      36%{opacity: 1;}
      63%{opacity: 1;}
      66%{opacity: .1;}
    }    
    @keyframes green{
      0%{opacity: .1;}
      66%{opacity: .1;}
      69%{opacity: 1;}
      97%{opacity: 1;}
      100%{opacity: .1;}
    }    
  </style>
</head>
<body>
  <div class="box">
    <div class="light red"></div>
    <div class="light yellow"></div>
    <div class="light green"></div>
  </div>
</body>
</html>

 

posted @ 2020-07-23 17:44  五环  阅读(819)  评论(0)    收藏  举报