[snkiz]

If there's no flexi space add a flexi margin, like the mini window.

Fixes #98 uses the method described there. I have not seen these three pr's work together. The testing suggests they should work together like the prototype with the changes.

[Firnschnee]

Merged, thanks! One follow-up in a8ce1a6: the rule never applied as written. Firefox keeps a fixed <toolbarspring id="vertical-spacer"> in every nav bar (ESR 153 and 160 alike), and FoxOne hides it through the old .titlebar-spacer { display: none } rule. Hidden or not, it still matched :has(> toolbarspring), so the margin always dropped out. That one's on me, it was my selector from the issue.

The fix only counts springs the user placed: :has(> toolbarspring:not(#vertical-spacer)). Tested on 160 with vertical tabs: 96px without a spring, none with one. Both margin rules now point at each other, so the shared value moves together.

Side note: that hidden spacer is Firefox's own grab area for vertical tabs, so FoxOne hiding it is why #98 came up in the first place. I kept our margin on the right instead of bringing the spacer back, since it would sit left of the URL bar.