Refine the public UI for a cleaner, more professional and scannable
landing experience without leaving the classic Habbo style:
- SurfaceCard: softer layered shadow, gradient accent hairline on the top
edge and a bolder header title across all public cards.
- Home: gradient hotel-name in the hero headline, shine effect on the
primary CTA, hairline on the top bar.
- Login/register: consistent avatar tiles with rounded corners, subtle
borders and a gentle hover lift; uniform username sizing.
- Add reusable theme-aware .card-hairline and .gradient-text utilities.