Why Does Adding a Top Margin to a Header Push the Entire Header Down?

Margin-Top Issue in Header Element

When adding a top margin to a header div, why does the entire header div get pushed down?

This behavior occurs because a top margin applied to the first visible element in a container often causes it to extend beyond its parent element's available space. As a result, the parent element expands vertically to accommodate the margin space, pushing all subsequent elements down.

Sample Code Snippet:

div#header {
  width: 100%;
  background-color: #eee;
  position: relative;
}

div#header h1 {
  text-align: center;
  width: 375px;
  height: 50px;
  margin: 50px auto;
  font-size: 220%;
  background: url('../../images/name_logo.png') no-repeat;
}

Solution:

To resolve this issue, you can add the overflow:auto property to the parent div. This will cause the parent div to scroll when the margin extends beyond its available space, keeping the header div from shifting down.

div#header {
  overflow: auto;
  ...
}

For more details, refer to the following link:

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