TabSet in Firefox 12.0/13.0 has overlapping tabs on 1st load

[Blama]

Hi Isomorphic,

if you open a showcase sample with #-link for the 1st time (or in a private window) in Firefox (Win10 FF 85.0.1), the TabSet has issues where the tabs are too near to each other.
Hovering the tabs fixes it. See here in 13.0d and here in 12.0p (each in current nightly) or this video:



My gut feeling says this might be related to fonts(?). As you can see, your "Privacy Policy and Cookies"-popup changes the font while the page loads.
I did not see this in Chromium based browsers just now, but remember that this behaviour has always been like this. And as I used Chromium as my normal browser for a long time, this might also happen there. But as I said, I could not reproduce just now.

Best regards
Blama

[Isomorphic]

We're not reproducing the issue on our end - perhaps it's dependent on the timing of your server interaction? If you set window.isc_useCSSFontAPI = false before the framework is loaded as documented here does it fix the issue? That switches the technique used to detect whether font loading is complete.