Answers for "cool border radius css"

border-radius circle using %

.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>

css border radius

-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;

border radius css

border-radius: 5px; /* The corners will be round */