The following CSS removes the border on the second nav level, sets the active subnav to always display, and sets the inactive subnavs to display when their parents are hovered.

下面的CSS样式删除了子菜单上的边框，设置活动的菜单项一直显示，并且设置非活动的菜单项，只在它们的父级菜单被鼠标经过时显示。

youdao

When a control is selected, it has a shaded border around it with solid (active) or hollow (inactive) "sizing handles," small squares that appear in the selection border.

当选定一个控件时，它的周围有阴影框以及实心(活动)或空心(非活动)“尺寸柄”，即出现在选框中的小方块。

youdao