Feature Request: Revamp CSS

[qbjl]

Is your feature request related to a problem? No. The website is good but the styling makes it look too round-ish.

Describe the changes needed I'd like a revamp of the CSS as it can use some improvements as like a better navigation bar and/or dialog boxes (HTML6 tag styling), and better UI as like buttons and text areas

Additional context I can help revamp the CSS if needed. I really like this website and I want to contribute. Also, border-radius: calc(0.5rem / 2);