How to make my map look better on mobile

I want to host a basic domain that at least for now is nothing but a uMap, e.g. you browse www.coolmap.com and it will load https://umap.openstreetmap.fr/en/map/cool-map_524123 but keep the original domain in the address bar.

The problem with using an iframe is that it loads very slow on a mobile, and the interface controls appear really small and don’t get bigger if you zoom in. I’ve tried ProxyPass with Apache as well but that doesn’t seem to work. Does anyone know of any other solution?