Hey — pushed something small and now it's down? This is almost always a build output problem, not a code problem. Something that was getting copied into _site/ isn't anymore.
Don't debug with the site down. Get back up first:
git revert HEAD --no-edit git push
3–5 minutes and you're back. Now you can look at what actually broke without pressure.
This is almost always caused by a change to the build script or config that excluded a file from the deploy output. After the rollback:
git show HEAD~1
Look for anything touching build_site.sh, promote.txt, or the deploy workflow YAML. That's where 90% of push-breaks come from.
Once you've found the issue, run the build locally before pushing the fix:
bash build_site.sh ls -la _site/ | head -20
If it looks wrong locally, it'll be wrong in CI. Confirm the files you expect are actually there before pushing.