This looks lovely, well done! Regarding the cut off, why not use:

min-width: 1199px; overflow-x: scroll;

on the <body> element, and change the 100vw on the 'css-obv7rs' element to 100%? (And you may need some more tinkering, but you get the general idea.)

You can still put a mobile popup there ("this has been designed for a desktop"), but mobile users can pan around if they wish - degraded experience, but can use if they're desperate.