:root {
  --bg: #111;
  --panel: #17171a;
  --line: #2a2a30;
  --ink: #e8e8ea;
  --dim: #8b8b95;
  --accent: #7aa2f7;
  --good: #22c55e;
  --bad: #ef4444;
  --warn: #eab308;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  min-height: 100vh;
}

/* ── shell ─────────────────────────────────────────────── */
.bar {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 10px 18px;
  border-bottom: 1px solid var(--line);
  background: var(--panel);
  position: sticky;
  top: 0;
  z-index: 2;
}

.brand {
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: lowercase;
  color: var(--accent);
}

.tabs { display: flex; gap: 6px; flex: 1; }
.tabs[hidden] { display: none; }      /* one view: no tab bar (main.js) */

.tabs button {
  background: none;
  border: 1px solid transparent;
  border-radius: 6px;
  color: var(--dim);
  padding: 5px 12px;
  font: inherit;
  font-size: 14px;
  cursor: pointer;
}
.tabs button:hover { color: var(--ink); }
.tabs button.active { color: var(--ink); border-color: var(--line); background: #1e1e23; }

.chip {
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--dim);
  white-space: nowrap;
  max-width: 40vw;
  overflow: hidden;
  text-overflow: ellipsis;
}
.chip.on { color: var(--good); border-color: #1d4a2e; }
.chip.off { color: var(--dim); }

main { padding: 22px 18px 40px; max-width: 1100px; margin: 0 auto; }

/* ── trainer ───────────────────────────────────────────── */
.row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }

select, .btn {
  background: #1e1e23;
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 7px 14px;
  font: inherit;
  font-size: 14px;
  cursor: pointer;
}
.btn:hover:not(:disabled) { border-color: var(--accent); }
.btn:disabled { opacity: 0.4; cursor: default; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #10131c; font-weight: 600; }

.card {
  position: relative;
  overflow: hidden;
  margin: 20px 0;
  padding: 26px 22px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
}
/* the trainer's "Show keys" switch, beside Start / Skip / Stop */
.t-toggle { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; color: var(--dim);
  cursor: pointer; user-select: none; }
.t-toggle input { margin: 0; accent-color: var(--accent); }
.t-toggle[hidden] { display: none; }
/* how far through the session: a thin bar on the card's bottom edge, no numbers */
.t-progress { position: absolute; left: 0; bottom: 0; height: 2px; width: 0; background: var(--accent);
  opacity: .75; transition: width 160ms linear; }

.chord {
  font-size: 64px;
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.02em;
}
.chord.idle { color: var(--dim); font-size: 34px; font-weight: 400; }
/* Sight-reading prompts: the same slot holds engraved notes instead of a name. */
.chord.staff { font-size: 0; line-height: 0; }
.chord.staff svg { display: block; max-width: 100%; height: auto; }

.prompt-line { color: var(--dim); margin-top: 8px; font-size: 15px; }


.verdict { margin-top: 16px; font-size: 15px; min-height: 22px; font-variant-numeric: tabular-nums; }
.verdict.ok { color: var(--good); }
.verdict.no { color: var(--bad); }

/* per-card grade breakdown (trainer `passed` events) */
.grade { margin-top: 10px; font-size: 14px; min-height: 20px; color: var(--dim);
         font-variant-numeric: tabular-nums; }
.grade .ease { font-weight: 600; padding: 1px 8px; border-radius: 999px;
               border: 1px solid var(--line); }
.grade .t-good { color: var(--good); }
.grade .t-warn { color: var(--warn); }
.grade .t-bad { color: var(--bad); }

.piano-wrap { width: 100%; overflow-x: auto; }
svg.piano { width: 100%; min-width: 640px; display: block; }
svg.piano rect { transition: fill 90ms linear; }
svg.piano text { fill: #9a9aa4; font-size: 7px; user-select: none; }
/* ⌨ musical typing: the computer key on each piano key it plays (keyboard.js) */
svg.piano text.kb-letter { fill: #202027; font-size: 13px; font-weight: 600; }
svg.piano text.kb-letter.on-black { fill: #f4f4f6; font-size: 10px; }

.summary { font-size: 15px; line-height: 1.7; }
.summary h3 { margin: 0 0 8px; font-size: 14px; text-transform: uppercase; letter-spacing: 0.1em; color: var(--dim); }

/* header sound controls */
.sound { display: inline-flex; gap: .4rem; align-items: center; margin-left: auto; margin-right: .6rem; font-size: .85rem; }
#srs-sel { max-width: 150px; }
.sound select, .sound button { background: #111; color: inherit; border: 1px solid #333; border-radius: 4px; padding: .15rem .4rem; font: inherit; }
.sound button:hover { border-color: #666; }
.sound button.on { border-color: var(--good); color: var(--good); }