3-22 Css实现自适应屏幕宽度的正方形

方式一：padding + 百分比

<style>
  html,
  body {
    margin: 0;
    padding: 0;
  }
  .outer {
    width: 20%;
    height: 0;
    padding-bottom: 20%;
    background-color: red;
  }
</style>
<body>
  <div class="outer"></div>
</body>

方式二：vw+vh

<style>
  html,
  body {
    margin: 0;
    padding: 0;
  }
  .outer {
    width: 20vw;
    height: 20vw;
    background-color: red;
  }
</style>
<body>
  <div class="outer">
    <p>love</p>
  </div>
</body>

缺点：会导致在元素上设置的 max-height 属性失效

方式三：伪元素 + margin(padding)-top 撑开容器

<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>
      html,
      body {
        margin: 0;
        padding: 0;
      }
      .outer {
        width: 20%;
        background-color: red;
        overflow: hidden;
        position: relative;
      }
      .outer::after {
        content: "";
        display: block;
        margin-top: 100%; /* margin 百分比相对父元素宽度计算 */
      }
      p {
        margin: 0;
        /* 解决内容，导致容器溢出 */
        position: absolute;
      }
    </style>
  </head>
  <body>
    <div class="outer">
      <p>
        Lorem, ipsum dolor sit amet consectetur adipisicing elit. Repudiandae,
        cupiditate. Labore alias eius magnam, pariatur beatae sed eos dolor non
        numquam laudantium dolorem error aspernatur maxime, reiciendis dolorum
        exercitationem! Quas?
      </p>
    </div>
  </body>
</html>
posted @ 2022-03-22 21:31  林见夕  阅读(177)  评论(0)  编辑  收藏  举报