<!DOCTYPE html>
<html>
<link rel='stylesheet' type='text/css' href='style.css'>
<style>
div.progress-bar {
width:100%;
}
body > div:nth-child(1) > .progress-bar { width: 20px; }
body > div:nth-child(2) > .progress-bar { width: 0px; }
body > div:nth-child(3) > .progress-bar { width: 50%; }
body > div:nth-child(4) > .progress-bar { width: 1em; }
body > div:nth-child(5) > .progress-bar { width: 100%; }
</style>
<body>
<div class="progress-element">
<div class="progress-bar">
</div>
</div>
<div class="progress-element">
<div class="progress-bar">
</div>
</div>
<div class="progress-element">
<div class="progress-bar">
</div>
</div>
<div class="progress-element">
<div class="progress-bar">
</div>
</div>
<div class="progress-element">
<div class="progress-bar">
</div>
</div>
</body>
</html>