Adding Scroll 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 many foreign trade e-commerce websites built with WordPress, many themes support mega menus. This can lead to very long content in certain submenus, which is not ideal for display. Therefore, we need to set it up so that 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 case above, 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	A scrolling mechanism should be provided if the content overflows the box.
no-display	If the content does not fit the content box, the entire box is removed.
no-content	Hide the entire content if it does not fit within the content box.