<h1>Viewport Units and Percentage</h1>

<div class="percent-parent">
  <div class="percent-child"></div>
</div>

<div class="viewport-parent">
  <div class="viewport-child"></div>
</div>
* {
  box-sizing: border-box;
}

body {
  text-align: center;
  font-family: 'Lato';
}

.percent-parent {
  width: 50%;
  height: 300px;
  background: orange;
  padding-top: 75px;
  margin-bottom: 75px;
}
.percent-child {
  width: 80%;
  height: 150px;
  background: rgba(125, 255, 0, 0.5);
}

.viewport-parent {
  width: 50%;
  height: 300px;
  background: orange;
  padding-top: 75px;
  margin-bottom: 75px;
}

.viewport-child {
  width: 80vw;
  height: 150px;
  background: rgba(125, 0, 255, 0.5);
}

External CSS

  1. https://fonts.googleapis.com/css?family=Lato

External JavaScript

This Pen doesn't use any external JavaScript resources.