Answers for "border radius / examples"

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>

how to round the corners of a div outline in css

div {
  outline: auto;
  outline-style: round;
}