Progress Bar with HTML and CSS

Solution 1:

#progressbar {
  background-color: black;
  border-radius: 13px;
  /* (height of inner div) / 2 + padding */
  padding: 3px;
}

#progressbar>div {
  background-color: orange;
  width: 40%;
  /* Adjust with JavaScript */
  height: 20px;
  border-radius: 10px;
}
<div id="progressbar">
  <div></div>
</div>

Fiddle

(EDIT: Changed Syntax highlight; changed descendant to child selector)

Solution 2:

http://jsfiddle.net/cwZSW/1406/

#progress {
    background: #333;
    border-radius: 13px;
    height: 20px;
    width: 300px;
    padding: 3px;
}

#progress:after {
    content: '';
    display: block;
    background: orange;
    width: 50%;
    height: 100%;
    border-radius: 9px;
}
<div id="progress"></div>