Why Does a Parent Div Have Zero Height with Floated Children?

Understanding the Height of a Parent Div with Floated Children

In the context of web design, the height of a div container can be influenced by its child elements. However, when those child elements are floated, an unexpected behavior can occur, resulting in a parent div with zero height.

To illustrate this, consider the following CSS:

#wrapper {
  width: 75%;
  min-width: 800px;
}
.content {
  text-align: justify;
  float: right;
  width: 90%;
}
.lbar {
  text-align: justify;
  float: left;
  width: 10%;
}

When you create HTML using this CSS, for example:

<div>
<p>You may notice that the page renders correctly, but when you inspect the DOM, the "#wrapper" div appears to have a height of 0px. This is because floated content removes itself from the normal flow of the document, essentially becoming removed from the document tree.</p>
<p>The consequence of this is that the parent div's height is not influenced by its floated children. As a result, the parent div remains at its default height of 0px.</p>
<p>To resolve this issue and ensure the parent div expands to encompass its floated content, you can use the "overflow: hidden" property on the parent div. This creates a new "block formatting context," which forces the floated children to remain within the parent's bounds.</p>
<p>Here's the updated CSS:</p>
<pre class="brush:php;toolbar:false">#wrapper {
  width: 75%;
  min-width: 800px;
  overflow: hidden; /* Added */
}

With this modification, the "#wrapper" div will now stretch to fit its floated children, allowing the page's layout to behave as expected.