You know those nights when you race towards a deadline, banging out the CSS as fast as you can, there comes a moment when you pause…wondering what keyword would get rid of that z-index on that anchor, then you make the best guess you can, and type: z-index: none; Then go on in life, as it “renders” like you wanted it, it works, no big deal. But it is. Specifying incorrect values might inject behav