x/website: provide portrait screen mode friendly style for mobile devices

[hyangah]

Browse https://tip.golang.org/cmd/go
from mobile devices, on portrait mode

Particularly the two column TOC is not ideal.

Does this issue reproduce with the latest release?

Yes.

What operating system and processor architecture are you using (go env)?

Chrome on android

[agnivade]

I had done some work (CL 129135) to generate the TOC at server side for the /search page. For the rest of the pages, AFAIR, the TOC is hard-coded to be 2 columns. Is this issue just about adjusting the no. of columns in TOC for mobile devices or are there other aspects to be tacked ?

@andybons @dmitshur - Is the TOC rendering logic going to be looked at in the new website revamp ?

[andybons]

@agnivade yes it’s likely we’ll look at it at some point.

[hyangah]

@agnivade I think switching to the single column mode when the width is not sufficient is sufficient for this bug.

I wished we could do something about the pre-formatted text width too but I guess I can live with it.

[seankhliao]

Seems no longer relevant now that it uses pkg.go.dev