Html代码
<div class="div1">
<a>11111111</a>
</div>
CSS代码
.div1{
margin-top: 25vh;
margin-left: 25vw;
width: 800px;
height: 600px;
background-color: antiquewhite;
}
.div1 a{
display: block;
width: 200px;
height: 80px;
background-color: aqua;
display: flex;
justify-content: center;
align-items: center;
}
图片效果：
重点：
display: flex;
justify-content: center;
align-items: center;
