<div class="container">
  <p>Hover over any of the following elements to see it animate into fully opaque. The first of all elements is fully transparent / invisible because it has <code>opacity: 0</code>; you can still hover it and see it come to view.</p>
    Notice how the background pattern on the body can be seen through the translucent elements.
  <div class="element element-0">
    <p>I have <code>opacity:0</code></p>
  <div class="element element-1">
    <div class="child">
      I am a descendant of my parent. I have the same opacity = 0.2;
  <div class="element element-2">
    <p>I have <code>opacity:.4</code></p>
  <div class="element element-3">
    <p>I have <code>opacity:.6</code></p>
  <div class="element element-4">
    <p>I have <code>opacity:.85</code></p>
body {
  color: #555;
  font-size: 1.1em;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  background-image: url(skulls.png);

.container {
  margin: 40px auto;
  max-width: 700px;

.element {
  padding: 20px;
  background-color: #0099cc;
  color: white;
  margin-bottom: 30px;
  min-height: 70px;
  /* for IE */

  zoom: 1;
  /* transition opacity */

  -webkit-transition: opacity .6s;

  transition: opacity .6s;

.child {
  background-color: #777;
  padding: 20px;

.element-0 {
  filter: alpha(opacity=0);
  opacity: 0;

.element-1 {
  filter: alpha(opacity=20);
  opacity: .2;

.element-2 {
  filter: alpha(opacity=40);
  opacity: .4;

.element-3 {
  filter: alpha(opacity=60);
  opacity: .6;

.element-4 {
  filter: alpha(opacity=85);
  opacity: .85;

.element:hover {
  filter: alpha(opacity=100);
  opacity: 1;