<ul class="container">
  <li><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/323064/eyes-like-the-sky.jpg" alt=""></li>
  <li><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/323064/gumboot-soup.jpg" alt=""></li>
  <li><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/323064/microtonal-banana.jpg" alt=""></li>
  <li><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/323064/polygondwanaland.jpg" alt=""></li>
  <li><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/323064/twelve-bar-bruise.jpg" alt=""></li>
  <li><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/323064/quarters.jpg" alt=""></li>
  <li><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/323064/sketches-of-brunswick-east.jpg" alt=""></li>
  <li><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/323064/nonagon-infinity.jpg" alt=""></li>
</ul>

*,
*::before,
*::after {
  box-sizing: inherit;
}

html,
input {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
  min-height: 100%;
}

img,
embed,
object,
video {
  max-width: 100%; // without it images break away from columns
  height: auto;
}

.container {
  list-style-type: none;
  padding: 0;

  // Create the display behavior
  display:-ms-grid;
  display: grid;
  // Create the columns
  -ms-grid-columns: 1fr 1fr 1fr 1fr 1fr;
  grid-template-columns: repeat(5, 1fr);

  -ms-grid-gap: 20px;
  grid-gap: 20px;

  // Control the overflow
  grid-auto-columns: 2fr;
  grid-auto-flow: column; // no IE11 Support

  background: whitesmoke;
}