Web z-index fixes

I’ve noticed an annoying trend where web developers are using z-index to place their header above every other element on the page.  When the window is made smaller this header often covers other more-important elements (like media players).

I’ve started using Stylish to fix these problems:

Di.fm (di.fm): 
#main-header { 
    z-index: 0; 
}

Groove (https://music.microsoft.com): 
#player { 
    z-index: 5;
} 
#header 
{ 
    z-index: 0; 
}