Closes #2344. The track carried no landmarks — 76 years of blank rail. Decade marks now sit under it, derived from the live span. The issue's own framing was wrong and is corrected in a comment there. It said roughly four years per thumb-pixel; measured against the real range, 1950-2026 on a ~300px track is 0.25 years per pixel, so an 8px thumb movement covers about two years. Out by a factor of sixteen. The problem is orientation, not precision. There was no way to see where 1985 sits, so the interaction was drag, read the number, drag again — with twelve seconds on the clock, in a dim room, one-handed. A mark to aim at puts the first movement close and leaves the +-1/+-5 buttons doing what they were designed for. Derived rather than pinned. #2337 made the bounds move: applyYearRange() sets min/max from the playlist in play, so marks nailed to fixed percentages would drift the moment a playlist reaches past the default. The scale is rebuilt from the same span, in the same function, so the bounds and the marks cannot disagree. Three details worth the extra lines: A range thumb's centre travels from thumbWidth/2 to width - thumbWidth/2 and never reaches the edge, so marks are laid out inside that inset. One at a true 100% would sit past the highest year the slider can select. The step widens past eight marks rather than letting labels collide. The default span lands on eight decades, about 35px apart at 10px type. Labels are two digits with an apostrophe — language-neutral, so no translation is needed, and narrow enough that eight fit. A span crossing a century would render '00 twice, so the short form is used only while it stays unambiguous and four digits take over otherwise. 7 tests, four of which fail against the unfixed code. Bundle and CSS rebuilt, 18 artifacts match. 2058 unit tests green. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01LYnmkDxHC2drccP1XFpJN4

Commits

Commits on Aug 23, 2026

Give the year slider something to aim at