At a specific width, the left nav doesn't show, but body is narrow expecting nav to show

[mrjones-plip]

Description

Steps To Reproduce

1. go to demo hextra site in firefox
2. make your browser ~767pixels wide

Expected Behavior

• the main body should either be 100% width with no left navigation or
• main body should be ~60% width and have the left navigation show

Actual Behavior

main body is ~60% width and no left navigation shows

Screenshots

All three sites demonstrate the same behavior shown here:

Screencast.From.2025-04-24.21-09-12.mp4

Environment

• Hugo Version: what ever is on hextra demo site, meteor.js site and cht demo site - they all do it
• Browser/OS: latest Chromium and and latest firefox on latest Bluefin
• Theme Version: ?

Additional Context

I guess I very meticulously resize my windows?!?