how else can I have a fullscreen overlay navigation on a phone from an accessible toggle button?

almost forgot to answer the question: because I don't know any better

One (unusual) approach I like because of the simplicity is to put all your navigation links in your footer, and the hamburger/menu button in the header is just an anchor link that scrolls down to your footer.

Unfortunately, accessible HTML solutions for well established UI patterns like menus and tooltips are still far too difficult to get right (anything that requires JavaScript usually).

Nice, and I agree - maybe… the desktop version gets a nav and on the phone it’s all one elder scroll. With section links if it gets too long. … but still need the entry point for lang versions

Actual answer: like this! https://codepen.io/Sfate/pen/kGbLzK

yep that works thank you - so to get the fullscreen overlay (since we only want it on the phones) a media query - maybe it should be the one gridcell navpage. But maybe the links should be listed for the robots ... if mobile is default/first there would be only one link - yeah maybe this is good.

You can do a lot with CSS these days: https://css-tricks.com/the-checkbox-hack/