<div class="box"><div class="center">居中效果</div></div>

/*第1種，垂直居中效果*/.box{    width: 200px;height: 200px;border: 1px solid #ccc;    position: relative; }.center{   width: 100px;height: 100px;background: gray;   margin: auto;position: absolute;top: 0;left: 0;bottom: 0;right: 0;  }

<div class="box2"><img class="center2" src="yz_p5.jpeg" alt=""/><span class="block"></span></div>

/*第2種 圖片垂直居中*//* span是輔助元素 vertical-align這個屬性的特點,它是相對兄弟級行高（line-height）來定位*/.box2{  width: 350px;height: 350px;border: 1px solid #F22727;  text-align: center;}.center2{ vertical-align: middle;}.block{ line-height: 350px;}/*跟父級一樣高*/

<div class="box3"><span class="center3"><img src="yz_p5.jpeg" alt=""/></span></div>

/*第3種，居中效果*/.box3{  width: 350px;height: 350px;border: 1px solid #F22727;display: table;text-align: center;}.center3{  display: table-cell;vertical-align: middle;}

<div class="box4"><img class="center4" src="yz_p5.jpeg" alt=""/></div>

/*第4種，居中效果 根據父元素來計算*/.box4{  width:300px;height: 300px;border: 1px solid #F22727;}.center4{  width: 200px;height: 200px;position: relative;left: 16%;top: 19%;}