Why isn't z-index working?
问题 I am trying to understand how z-index works. In order to do that, I have created a simple example which consists of five divs. Each one is a child of the previous, except for the first. My objective is to make the first div, the parent container of all other divs, be shown on top of all of the others, effectively hiding them. In order to achieve my goal, I have put z-index properties on all the divs and on the parent div I have put an exaggerated value of a 100 to make sure it is higher than