固定宽高度，让上传的图片不变形

<style type="text/css">

.img-responsive {
max-width: 100%;
height: 0;
padding-bottom: 40%; //div大小的比例
background-color:#ff0000;
overflow: hidden;
}

.img-responsive img {
width: 100%;
}

</style>

<div class="img-responsive">
<img src="http://d13yacurqjgara.cloudfront.net/users/14765/screenshots/1392915/mrbc-badge-....png"
/>
</div>