center a box in the middle of the screen

In this case my anchor this week becomes driving almost 2hrs outside of Atlanta to one of my favorite hard core gyms in the world.. MetroFlex aka The Dungeon. The gym owners turn the heat way up so it becomes a fun sweat box and the gym members just watch from afar and leave me alone. I happily drive myself long distances to find MY ANCHOR. Our anchor allows us to have balance, focus and be as productive as possible. And if you're in the middle of a heavy set and your headphones start to fall off your head, like mine did here.. well.. f*ck the headphones. Let em break and fall. You can always get a new pair, but the iron ain't ever gonna lift itself.
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:host-context()

The :host-context() CSS pseudo-class function selects the shadow host of the shadow DOM containing the CSS it is used inside (so you can select a custom element from inside its shadow DOM) — but only if the selector given as the function's parameter matches the shadow host's ancestor(s) in the place it sits inside the DOM hierarchy.
:host-context() css reference