圆形的cornes(边界半径)Safari问题。

.activity_rounded  {
    -webkit-border-radius: 50%;
    -moz-border-radius: 50%;
    border-radius: 50%;
    -khtml-border-radius: 50%;
    border: 3px solid #fff;
    behavior: url(css/PIE.htc);
}
<img src="img/demo/avatar_3.jpg" class="activity_rounded" alt="" />
.activity_rounded  {
    -webkit-border-radius: