Teacher Miejie Shitai, hello:
I revised it according to what you said, as shown in the picture below. What is the reason for this?
Reason: If absolute positioning is set for an element, the element will break away from the document flow, so it will cover other elements.
Set the level of the drop-down box under the shopping cart to a higher level, z-index: 100
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Reason: If absolute positioning is set for an element, the element will break away from the document flow, so it will cover other elements.
Set the level of the drop-down box under the shopping cart to a higher level, z-index: 100