css sets hierarchical relationship. If position cannot be set, please ask a master_html/css_WEB-ITnose

The existing demo design is as follows:



#left_nav has a movement action and can be moved to the right, and it is required to be located on #right_content after moving (#right_content can be used during #left_nav movement) at the current position), but the position cannot be set for #left_nav, which means that the hierarchical relationship between #left_nav and #right_content cannot be set using z-index, and #left_nav cannot be used as the parent element of #right_content. At this time, if How do you want #left_nav to be above #right_content?

Reply to discussion (solution)

The default position is relative, if you move it it should be on top