$zindex: (

modal: 9000, 
overlay: 8000, 
dropdown: 7000, 
adminnav: 5000, 
header: 4000, 
header-contents: 4100, 
content: 3000, 
content-above: 3100, 
footer: 2000
);

// How to use: //.example-header // z-index: map-get($zindex, header)