Contributors to this thread:

My #ktistec tweaks repository (https://src.jayvii.de/pub/ktistec-tweaks/index.html) now also includes adjustments for small screens (for example, if you use ktistec on your smart-phone), such as pagination buttons that are easier to hit with your thumbs or an iconified navigation bar at the top, so it actually fits the screen. It's using the very nice feather icons!

Image description: Screenshot of the settings-page of my ktistec-instance viewed from a smartphone. The top navigation bar has icons rather than labels, such that it fits the small screen.

The navigation bar uses the default labels on wider screens. Only if they do not fit, it switches to the icons.

One obvious downside is, that the icons are added as ::after content and therefore do not inherit HTML attributes such as "title" or "alt". Not so great for #accessibility #a11y. If anyone has tips on that, I am all ears!