//源码
img {
 vertical-align: middle;
}
.img-responsive,
.thumbnail > img,
.thumbnail a > img,
.carousel-inner > .item > img,
.carousel-inner > .item > a > img {
 display: block;
 max-width: 100%;
 height: auto;
}
.img-rounded {
 border-radius: 6px;
}
//缩略图模式
.img-thumbnail {
 display: inline-block;
 max-width: 100%;
 height: auto;
 padding: 4px;
 line-height: 1.42857143;
 background-color: #fff;
 border: 1px solid #ddd;
 border-radius: 4px;
 -webkit-transition: all .2s ease-in-out;
  -o-transition: all .2s ease-in-out;
   transition: all .2s ease-in-out;
}
.img-circle {
 border-radius: 50%;
}