<ul class="aaa">
<li><img src="http://placehold.it/150x150" /></li>
</ul>
<ul class="bbb">
<li><div><img src="http://placehold.it/150x150" /></div></li>
</ul>
.aaa li{
display: inline-block;
width: 160px;
}
.aaa li img{
width: 150px;
border: 5px solid #ececec;
-webkit-border-radius: 50%;
-moz-border-radius: 50%;
-ms-border-radius: 50%;
-o-border-radius: 50%;
border-radius: 50%;
}
.bbb li{
.mobile-share_fb{ display:block; background:url("http://www.shopunt.com/css/mobile/images/mobile-s9398562778.png") no-repeat; background-position: 0 -1648px; height: 80px; width: 80px;}
.shrink-attr{ background-size: 152px 2104px; width: 40px; height: 40px; background-position: 0 -824px;}
.fb-test{ display:block; background:url("http://www.shopunt.com/images/logo_welcome.jpg") no-repeat; background-size:50% 50%; width: 105px; height: 105px;}
<style type="text/css">
#test
{
width:300px;
height:300px;
background-color:blue; /*全部, firefox*/
background-color:red\9; /*all ie*/
background-color:yellow\0; /*ie8*/
+background-color:pink; /*ie7*/
_background-color:orange; /*ie6*/
}
:root #test { background-color:purple\9; } /*ie9*/
@media all and (min-width:0px){ #test {background-color:black\0;} } /*opera*/
@media screen and (-webkit-min-device-pixel-ratio:0){ #test {background-color:gray;} } /*chrome and safari*/
</style>