代码
<!DOCTYPE html>
<html><head><meta charset="UTF-8">
<title>TEST IMG CENTER</title>
</head>
<style>
img{
width: auto;height: auto;max-width: 100%;max-height: 100%;
}
div{
width:350px;height:280px;border: 4px black solid;
display:flex;justify-content:center;align-items:center
}
</style>
<body>
<div>
</div>
</body>
</html>
