css/slash/04.html

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>
    body {
      background: #eee;
    }

    div {
      position: relative;
      margin: 50px auto;
      width: 100px;
      height: 100px;
      box-sizing: border-box;
      background-color: deeppink;
      line-height: 120px;
      text-indent: 5px;
    }

    div::before {
      content: "";
      position: absolute;
      left: 0px;
      top: 0;
      right: 0;
      bottom: 0;
      -webkit-clip-path: polygon(0 0, 0 100px, 100px 100px, 0 0);
      background: #fff;
      /* border: 1px solid #333; */
      transform: translateX(0px);
      /* animation: move 5s 1 linear; */
    }

    div::after {
      content: "";
      position: absolute;
      left: 0;
      top: 0;
      right: 0;
      bottom: 0;
      -webkit-clip-path: polygon(100px 99px, 100px 0, 1px 0, 100px 99px);
      background: #fff;
      /* border: 1px solid #333; */
      transform: translateX(0px);
      /* animation: move 5s infinite linear; */
    }

    @keyframes move {
      40% {
        transform: translateX(0px);
      }
      100% {
        transform: translateX(0px);
      }
    }
  </style>
</head>

<body>
  <div></div>
</body>

</html>