Why Does Overlapping Element Background Appear Behind Content?

Content Not Covered by Background of Overlapping Element

This discrepancy arises because of the distinct rendering order of CSS components. The HTML elements are rendered in the following sequence:

1. Backgrounds and borders of parent elements
2. Backgrounds and borders of child elements
3. Content of child elements

In the example provided, the second div has a negative margin-top applied, causing it to overlap the first div. However, due to the above-mentioned rendering order, the background of the second div is painted below the content of the first div.

To clarify, the nesting order and individual element layout influence the visual output. The content is placed atop the backgrounds because of the perceived significance of text. This order of precedence can be observed in more intricate scenarios:

body {
  background: pink;
}

div {
  background: red;
  border: 3px solid brown;
  margin-bottom: -20px;
}

The rendering order for this example is as follows:

1. Background of
2. Background and border of first
3. Content of first
4. Background and border of second
5. Content of second

However, by assigning a position: relative to an element, we can modify this behavior. This action creates a new stacking context, allowing us to control the element's placement using z-index. This mechanism makes it possible to visually position elements in the desired order, regardless of the HTML structure.

It is important to note that this phenomenon is not particularly intuitive. However, by understanding the CSS rendering order, we can anticipate and control these visual effects.

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