Dark Premium Mobile Auth UI

I need a pair of sleek, dark-themed authentication screens—Login and Sign-Up—built directly in Figma for a mobile app. The look should feel premium: deep backgrounds, refined typography, and subtle highlights that guide the user without overwhelming them. Final files must be fully editable, using organized layers, styles, and components so my team can tweak text or colors effortlessly later on.

Please share a quick outline of your approach, any similar dark-mode work you have done, and the turnaround time you would need.