<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
.container {
width: 200px;
height: 200px;
overflow: auto;
resize: both;
text-align: center;
background: #691;
}
.square{
display: inline-block;
vertical-align: bottom;
height: 100%;
max-width: 100%;
position: relative;
overflow: hidden;
}
.square img {
vertical-align: bottom;
}
.square-inner {
position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;
height: 0;
margin: auto;
padding-bottom: 100%;
background: lightcoral;
}
</style>
</head>
<body>
<div class="container">
<div class="square">
<img src="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" height="100%">
<div class="square-inner"></div>
</div>
</div>
</body>
</html>
标签：square,bottom,100%,布局,height,width,contain,align,CSS From： https://www.cnblogs.com/chen8840/p/17562227.html