css webkit-border-radius code example
Example 1: css circle border
.circle {
background-color:#fff;
border:1px solid red;
height:100px;
border-radius:50%;
-moz-border-radius:50%;
-webkit-border-radius:50%;
width:100px;
}
<div class="circle"></div>
Example 2: how to round the corners of a div outline in css
div {
outline: auto;
outline-style: round;
}