元素水平垂直居中的六种方法

<style>
  .father {
    width: 400px;
    height: 400px;
    background-color: pink;
    position: relative;
  }
  .son {
    width: 200px;
    height: 200px;
    background-color: aquamarine;
    position: absolute;
    left: 50%;
    top: 50%;
    margin-left: -100px;  /* 子盒子宽度的一半 */
    margin-top: -100px;   /* 子盒子高度的一半 */
  }
</style>
<div class="father">
  <div class="son"></div>
</div>

<style>
  .father {
    width: 400px;
    height: 400px;
    background-color: pink;
    position: relative;
  }
  .son {
    width: 200px;
    height: 200px;
    background-color: aquamarine;
    position: absolute;
    left: 50%;
    top: 50%;
       transform: translate(-50%, -50%);
  }
</style>
<div class="father">
  <div class="son"></div>
</div>

<style>
  .father {
    width: 400px;
    height: 400px;
    background-color: pink;
    position: relative;
  }
  .son {
    width: 200px;
    height: 200px;
    background-color: aquamarine;
    position: absolute;
    /* 以下四个属性必须都要写上 */
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    margin: auto;
  }
</style>
<div class="father">
  <div class="son"></div>
</div>

<style>
  .father {
    width: 400px;
    height: 400px;
    background-color: pink;
    display: flex;
    justify-content: center; /* 主轴居中 */
    align-items: center; /* 侧轴居中 */
  }
  .son {
    width: 200px;
    height: 200px;
    background-color: aquamarine;
  }
</style>
<div class="father">
  <div class="son"></div>
</div>

<style>
  .father {
    width: 400px;
    height: 400px;
    background-color: pink;
    display: table-cell;
    vertical-align: middle;
    text-align: center;
  }
  .son {
    width: 200px;
    height: 200px;
    background-color: aquamarine;
    display: inline-block;
  }
</style>
<div class="father">
  <div class="son"></div>
</div>

<style>
  .father {
    width: 400px;
    height: 400px;
    background-color: pink;
    display: grid;
    align-items: center;
    justify-content: center;
  }
  .son {
    width: 200px;
    height: 200px;
    background-color: aquamarine;
  }
</style>
<div class="father">
  <div class="son"></div>
</div>