Drawing animated arc with pure CSS

Question

I know it is possible to draw and animate arcs in svg and canvas. However, is it possible in css?

I have created an arc using the following method:

.         


        

Answer 1

EDIT: Using two arcs, you can have the animation draw cleanly from left-to-right AND have the background show through:

http://jsfiddle.net/sPv4A/6/

Vendor prefixes not included for CSS:

.arcContain {
  width: 150px;
  height: 400px;
  position: relative;
  margin: 20px;
}

.arc {
  width: 150px;
  height: 400px;
  border-radius: 50%;
  border: 2px solid black;
  border-bottom: 2px solid transparent;
  position: absolute;
  top: 0;
  right: 0;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
}

.archideLeft .arc {
  top: auto;
  bottom: 0;
  right: auto;
  left: 0;
}

.archide {
  width: 50%;
  height: 0%;
  position: absolute;
  top: 0;
  right: 0;
  overflow: hidden;
  animation: appear 1.2s ease-in 1.2s forwards;
}

.archideLeft {
  top: auto;
  bottom: 0;
  right: auto;
  left: 0;
  animation: appear 1.2s ease-out forwards;
}

@keyframes appear {
  to {
    height: 100%;
  }
}

OLD ANSWER: Maybe using two child divs to cover it up, and then have them shrink away to reveal it:

.arc {
  width: 150px;
  height: 400px;
  border-radius: 50%;
  border-right: 1px solid black;
  border-left: 1px solid black;
  border-top: 1px solid black;
  border-bottom: 1px solid white;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
  position: relative;
}

.arcInner {
  background: white;
  height: 402px;
  width: 77px;
  position: absolute;
}

.arcLeft {
  top: -2px;
  left: -2px;
  -webkit-transition: height 2s linear;
  -moz-transition: height 2s linear;
  -ms-transition: height 2s linear;
  -o-transition: height 2s linear;
  transition: height 2s linear;
}

.arcRight {
  bottom: 0;
  right: -2px;
  -webkit-transition: height 2s 2s linear;
  -moz-transition: height 2s 2s linear;
  -ms-transition: height 2s 2s linear;
  -o-transition: height 2s 2s linear;
  transition: height 2s 2s linear;
}

.appear .arcInner {
  height: 0;
}