The scale was on no grid: radii 6/10px and type 12.48/13.6/15.2/16.8/21.6px. That is what fractional rem buys you — sub-pixel text rendering, and no two components agreeing on a size. --r1/--r2 6/10px -> 8/12px --f0..--f4 12.48/13.6/15.2/16.8/21.6 -> 12/14/16/18/22 Read off bluesky-social/social-app's alf tokens (src/alf/tokens.ts at ef171e289, the last public copy before they moved to the @bsky.app/alf package): their radii are 2/4/8/12/16 and type 10/12/14/16/18/20/22/26/32/40. Ours is now a subset that lands on theirs. Kept in rem so a reader who raises their browser font size still gets it. Body text is now 16px at BOTH widths, which is bsky's `md` exactly. The mobile step-up to --f3 is removed: it was added when the base was 15.2px and read small on a phone, so with a correct 16px base it would have overshot to 18px — larger than any mainstream client sets body text. Its sibling padding reduction, which is what actually bought the space, stays. Measured (computed-style fingerprint): 105 properties moved, all downstream of font-size — 37 font-size, 35 line-height, 30 text-box width/height, 2 radius, 1 margin. No colour moved. No overflow at 360/390/768/1280. Phase 1b of the visual-parity order. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>