<div class="container">
  <p>
    Change the values of the <code>background-size</code> property on both elements to see how the background image will be sized differently:
  </p>
  <div class="element element-1"></div>
  <div class="element element-2"></div>
</div>
* {
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

body {
  background-color: #F5F5F5;
  color: #555;
  font-size: 1.1em;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

.container {
  width: 90%;
  margin: 30px auto;
}

.element {
  padding: 20px;
  margin: 30px 0;
  color: white;
  height: 400px;
  border: 5px solid black;
  background-repeat: no-repeat;
}

.element-1 {
  background-image: url(http://tympanus.net/codrops-playground/assets/images/cssref/properties/background-size/stationary2.jpg);
  background-size: auto 100%;
}

.element-2 {
  /* IE <= 9 */

  background-image: filter: progid: DXImageTransform.Microsoft.gradient( startColorstr='#ee71a9', endColorstr='#006699', GradientType=1);
  background-image: -webkit-linear-gradient(to bottom, #ee71a9, #006699);
  background-image: linear-gradient(to bottom, #ee71a9, #006699);
  background-size: 400px 300px;
}