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                <h1>CSS sizing: Extrinsic relative units</h1>

<div class="ext-fluid">
  This is also a block-level box with some content in it. But its <code>width</code> has been set to <code>40%</code> and its <code>height</code> set to <code>30%</code>. When using percentages, its values are resolved against the dimensions of its containing
  block, in this case, the <code>body</code> element. Depending on the size of the viewport you're using to view this, there may or may not be content overflow.</div>


                .ext-fluid {
  width: 40%;
  height: 30%;

.ipsum {
  color: maroon;

/* General styles */
html {
  font-size: 125%;
  height: 100%;

body {
  height: 100%;
  padding: 0.5em;

div {
  border: 1px dashed;
  line-height: 1.3;

h1 {
  font-size: 1.618em;
  margin-bottom: 0.5em;
  font-weight: bold;

code {
  font-family: monospace;