HTML5 / CSS3 Circle with Partial Border

Question

Is it possible to create a circle using only HTML5 / CSS3 which has a border that only goes part way around the circle? If not, what techniques can I use to accomplish this

Answer 1

Simplest way to animate this is using css keyframes.

http://jsfiddle.net/8SUPX/644/

/**
 * HTML5 / CSS3 Circle with Partial Border
 * http://stackoverflow.com/q/13059190/1397351
 */
* { margin: 0; padding: 0; }
.circle {
	position: relative;
	margin: 6em auto;
	width: 12em; height: 12em;
	border-radius: 50%;
	background: transparent;
	border:20px solid #efefef;
	border-top-color: #efefef;
    border-right-color: #efefef;
    border-bottom-color: #efefef;
    border-left-color: #efefef;
    
    -webkit-transition:.5s;-moz-transition:.5s;transition:.5s;
}
.circle:hover{
      -webkit-animation:  animix 0.5s 1;
      -webkit-animation-fill-mode: forwards;
      -moz-animation:  animix 0.5s 1;
      -moz-animation-fill-mode: forwards;
      animation:  animix 0.5s 1;
      animation-fill-mode: forwards;
}



  //Animate
   @-webkit-keyframes animix {
    0% { 
      border-top-color: transparent;
      border-right-color: transparent;
      border-bottom-color: transparent;
      border-left-color: transparent;
    }
     25% { 
       border-top-color: red;
       border-right-color: transparent;
       border-bottom-color: transparent;
       border-left-color: transparent;
     }
     50% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: transparent;
       border-left-color: transparent;
     }
     75% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: red;
       border-left-color: transparent;
     }
     100% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: red;
       border-left-color: red;
     }
   }
   
      @keyframes animix {
    0% { 
      border-top-color: transparent;
      border-right-color: transparent;
      border-bottom-color: transparent;
      border-left-color: transparent;
    }
     25% { 
       border-top-color: red;
       border-right-color: transparent;
       border-bottom-color: transparent;
       border-left-color: transparent;
     }
     50% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: transparent;
       border-left-color: transparent;
     }
     75% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: red;
       border-left-color: transparent;
     }
     100% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: red;
       border-left-color: red;
     }
   }