The narrow editorial scrollbar that's been on ferrlabs.com is now consistent across every FerrLabs site:

• @ferrlabs/styles base layer enriched with scrollbar-width: thin + scrollbar-color for Firefox/Edge (the existing ::-webkit-scrollbar-* rules only worked in Chromium / Safari).
• ::-webkit-scrollbar-thumb:hover darkens the thumb on hover for affordance.
• Inlined on FerrFlow / FerrTrack / FerrGrowth sites that don't import @ferrlabs/styles — same look without forcing the dep.
• Dark variant on FerrGames site with the cartes physiques palette colors.

Visual: 10px wide track, slate thumb at 28% opacity, 45% on hover.