Add scrolling functionality to WordPress dropdown menus

Today, I set up a scroll function for a client's foreign trade website menu, making a record here.For some foreign trade websites using WordPress for e-commerce, many themes support mega menus, which can result in very long content for certain submenus, making it difficult to display. Therefore, we need to set up a function where a scrollbar appears after exceeding a certain number of pixels. The method is simple: just add an overflow-y parameter.

ul ul{
    max-height:500px;
    overflow-y:scroll;
}

For example, in the above case, the maximum height is set to 500px, and then overflow-y is changed to scroll. The overflow-y property specifies whether to clip the top/bottom edge content if it overflows the element's content area. It supports the following values:

值	Description
visible	Content is not clipped and may be rendered outside the content box.
hidden	Content is clipped - no scrolling mechanism is provided.
scroll	Content is clipped - a scrolling mechanism is provided.
auto	If the content overflows the box, a scrolling mechanism should be provided.
no-display	If the content does not fit the content box, the entire box is removed.
no-content	If the content does not fit the content box, the entire content is hidden.