I'm looking for some help improving the CSS for https://ramdass-search.net/

First and foremost it should be mobile-friendly, and I'm not skilled enough in CSS to make it happen in a short amount of time.

The site should remain JS-free, so I don't want to use bootstrap or some other off-the-shelf framework.

No compensation, I'm providing the site free of charge, your contribution should be considered a donation to the people using the site.