Dear @Lucas-G
Looking into Viewport Units would likely be very helpful 🌝
You can calculate dimensions based on your browsers screen size = VH & VW ( Viewport Heights & Viewport Width ).
https://www.w3schools.com/cssref/css_units.asp
Also this should help when needing to apply this CSS to Lay Theme Elements:
https://laytheme.com/documentation.html#custom-css-styling
Hope this helps and have a wonderful day Lucas 🌝
Sincerely
Richard