The shopping cart drop-down box appears below the search box

Question

Teacher Miejie Shitai, hello:

I revised it according to what you said, as shown in the picture below. What is the reason for this?

Answer 1

Reason: If absolute positioning is set for an element, the element will break away from the document flow, so it will cover other elements.

Answer 2

Set the level of the drop-down box under the shopping cart to a higher level, z-index: 100