Attempting to center unhidden div

[SdeGeata]

Greetings;

I am currently using the MotionEye module with autohide activated and a webhook unhiding it. The module is assigned to the "fullscreen_above" region in the mirror. I am using this same configuration for some other hidden modules. My issue is that I am trying to center the MotionEye module within that div referencing the module directly from the custom.css file, though it doesn't seem to be working. I assume the error is in the reference, this is what I have so far:

.MMM-MotionEye { position: absolute; top: 0px; left: calc(50% - 625px); // Module is set to 1250px width in config.js }

can you point me in the right direction?