🎯 Sync Lab — time each song line against its video, save picks, submit for review

The four panels — 🎼 Timing sources (left): where times come FROM — ready-made timed lyrics fetched from lrclib.net (community "LRC" karaoke files: plain text with a [mm:ss.xx] stamp per line), the 📌 live site sync, or your ✏️ raw edit. ⏱ Timing board (bottom right): the editable truth, one row per song-page line; everything you save comes from here. 👀 Lyrics preview (top right) + video overlay: a read-only mirror of the board — click to seek, never to edit. 💾 Saved picks (bottom left): your per-song exports.
What loads when you pick a song — priority: your saved pick (from 💾, this browser) → the site's live sync (📌 card) → empty. The state pill next to the song tells you which.
The timing board is the source of truth. Every edit (⏱/R stamp, typed time, ←→ nudge, ± shift) instantly re-drives the lyrics preview and the video overlay. Exception: once you hand-edit the ✏️ raw text, that text takes over and the board stops rewriting it.
Source times off by a constant? (e.g. the video has an intro the album lacks) Prefill from the source, hit ▦ select all, and shift once — that's the global offset. Shifting moves ONLY blue-selected rows, never anything implicit: ▦ select all selects everything, ⇓ select to end selects green line→end (for drift from some point on), click + shift-click bounds a middle-only span. − shift earlier / + shift later decide the direction, the box is just the amount, and ⟲ undoes the last shift or refill.
📣 fan-chant lines are stampable too — chant-guide videos contain the chants, so give them times and they'll highlight on the song page.
↳ overlay shouts — a chant sung over a line (Make Me Happy's name-calls) shows as an indented sub-row under its line with its own ⏱: the line's time is when the line starts, the sub-row's is the exact moment the shout lands. ↑↓ walk onto it like any row, R stamps it (R on a line that has one hands the green line straight to its shout), ←→ nudge it, and it shows on the video overlay + lyrics preview at its moment. Optional — untimed, the site just lights it with its line.
Saving: 💾 Save pick puts this song's board into the export box (kept in this browser). Unsaved board edits are lost if you reload or switch songs. The site itself only updates after your 📮 submitted export is reviewed and shipped.
Candidates: duplicates are collapsed (≈N hidden); same-lyrics candidates preview the lines where their timings differ most; ⛔ in the song list = no video on the page yet, paste one to audition.
Is my work safe when I click another source? Rows you stamped or typed are KEPT — a source click only refills untouched rows. Two exceptions ask for confirmation first: the 📌 site-sync card (resets the whole board) and switching sources after hand-editing the raw text (discards that text). ↻ refill replaces stamps by design — that's what ⟲ undo is for.
The green line is the board's ONE active row: every key acts on it. It follows the song as it plays (so R stamps the row you're hearing) and goes wherever you point it with ↑↓ or a click. It holds still in three cases: while you're typing a time, while rows are blue-selected for a shift, and right after a stamp (so rapid R,R,R never gets pulled backward).
Keys: R stamp the green line — it then ADVANCES to the next row (rapid R,R,R times a whole playthrough); the stamped row flashes bright, and ↑ jumps back to it and replays. space replay the green line · ↑↓ move it (a timed row replays as you land on it) · ←→ nudge its time ∓0.1s · ZX scrub video ∓2s.