width:100% vs. width:inherit

See jsfiddle http://jsfiddle.net/bt5nj/2/ and http://jsfiddle.net/bt5nj/3/

width:inherit inherits width that defined by parent.

HTML:

  <div id="parent">
      <div id="child"></div>
  </div>​

CSS:

  #parent {
      width:50%;
      height:30px;
  }

  #child {
      width:inherit;
      height:100%;
      background-color:red;
  }

This makes child width 25%, but if I redefine it with width:100% it will define width of child 50%.

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