:root {
  --bg: #14161b;
  --panel: #1d2027;
  --border: #2d313b;
  --text: #e8e9ec;
  --muted: #8b909c;
  --accent: #6aa8ff;
  --good: #3ccf7a;
  --bad: #ff5d5d;
  --warn: #f5c451;
  /* Mastery levels: one blue hue, darker = less practised, lighter = mastered (validated ordinal ramp). */
  --lvl-1: #184f95;
  --lvl-2: #256abf;
  --lvl-3: #3987e5;
  --lvl-4: #86b6ef;
  /* Diagrams */
  --paper: #f7f5ef;
  --ink: #23252b;
  --wood: #3a2c22;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.4 system-ui, "Segoe UI", sans-serif;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  padding: 12px 24px;
  border-bottom: 1px solid var(--border);
}
header h1 { margin: 0; font-size: 20px; font-weight: 600; }
.header-controls { display: flex; align-items: center; flex-wrap: wrap; gap: 8px; }
.status { font-size: 13px; padding: 3px 10px; border-radius: 999px; background: var(--panel); }
.status.on { color: var(--good); }
.status.off { color: var(--bad); }

select, button, input[type=number], .chord-input, textarea {
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 10px;
  font: inherit;
}
button { cursor: pointer; }
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent); color: #0b0b0b; border-color: var(--accent); font-weight: 600; min-width: 90px; }
button.mini { padding: 3px 10px; font-size: 13px; }
button.active, button[aria-pressed="true"] { border-color: var(--accent); color: var(--accent); }
button:disabled { opacity: .45; cursor: default; }
[hidden] { display: none !important; }

.tabs { display: flex; gap: 4px; padding: 10px 24px 0; border-bottom: 1px solid var(--border); }
.tabs button { border: none; border-bottom: 2px solid transparent; border-radius: 0; background: none; padding: 8px 16px; color: var(--muted); }
.tabs button[aria-selected="true"] { color: var(--text); border-bottom-color: var(--accent); }

main { max-width: 1200px; margin: 0 auto; padding: 20px 24px; }

.panel { background: var(--panel); border: 1px solid var(--border); border-radius: 8px; padding: 14px 16px; }
.note { color: var(--muted); font-size: 13px; margin: 6px 0; }
.muted-text { color: var(--muted); }
.row { display: flex; align-items: center; flex-wrap: wrap; gap: 8px; }
h2 { margin: 0; font-size: 17px; font-weight: 600; }
h3 { margin: 0 0 6px; font-size: 15px; }
code { background: var(--bg); padding: 0 4px; border-radius: 4px; }

/* ---- Drill ---- */
.stage { display: flex; justify-content: center; align-items: center; gap: 48px; flex-wrap: wrap; min-height: 300px; }
.stage-main { text-align: center; min-width: 260px; }
.stage-side { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.chord-name { font-size: 96px; font-weight: 700; line-height: 1; transition: color .15s; }
.chord-name.good { color: var(--good); }
.chord-long { color: var(--muted); font-size: 18px; margin-top: 8px; min-height: 1.4em; }
.badge { display: inline-block; margin-top: 8px; padding: 2px 10px; border-radius: 999px; border: 1px solid var(--warn); color: var(--warn); font-size: 13px; font-weight: 600; }
.feedback { min-height: 1.6em; margin-top: 10px; font-size: 18px; font-weight: 600; }
.feedback.good { color: var(--good); }
.feedback.bad { color: var(--bad); }
.feedback.big { font-size: 26px; color: var(--accent); }
.actions { display: flex; justify-content: center; gap: 10px; margin: 10px 0 16px; }

.diagram { background: var(--paper); border-radius: 10px; padding: 8px 10px 2px; line-height: 0; }
.diagram:empty { display: none; }
.diagram-hidden { line-height: 1.4; color: #555; padding: 60px 30px; text-align: center; font-size: 15px; }
.diagram-hidden span { font-size: 12px; color: #888; }
button.link { background: none; border: none; color: var(--accent); padding: 2px 4px; font-size: 14px; text-decoration: underline; text-underline-offset: 3px; }
.positions-note { flex-basis: 100%; text-align: center; margin: 0 0 2px; }
.tab-view { background: var(--paper); border-radius: 10px; padding: 4px; line-height: 0; }
.compare { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin: 0 0 16px; }
.compare-card {
  display: flex; flex-direction: column; align-items: center; gap: 4px;
  background: var(--paper); color: #333; border: 3px solid transparent; border-radius: 10px; padding: 6px 6px 8px;
}
.compare-card:hover { border-color: var(--accent); }
.compare-card.current { border-color: var(--good); cursor: default; }
.compare-name { font-size: 12px; max-width: 150px; line-height: 1.25; }
.compare-none { color: #777; font-size: 13px; padding: 50px 14px; }

/* SVG diagram parts */
.chord-box .string, .chord-box .fret { stroke: var(--ink); stroke-width: 1.5; }
.chord-box .nut { stroke: var(--ink); }
.chord-box .dot { fill: var(--ink); }
.chord-box .dot.heard { fill: #1f9d55; }
.chord-box .finger { fill: #fff; font-weight: 700; font-family: system-ui, sans-serif; }
.chord-box .open { stroke: var(--ink); }
.chord-box .open.heard { stroke: #1f9d55; }
.chord-box .muted { stroke: #9a3b3b; }
.chord-box .pos, .chord-box .note-name { fill: #555; font-family: system-ui, sans-serif; }

/* ---- Fretboard ---- */
.board { margin-top: 4px; }
.fretboard-wrap svg { width: 100%; height: auto; display: block; }
.fretboard .neck { fill: var(--wood); }
.fretboard .fret { stroke: #b9b2a6; }
.fretboard .nut { stroke: #ece6d8; }
.fretboard .string { stroke: #d8d2c4; }
.fretboard .inlay { fill: #6b5747; }
.fretboard .fret-num, .fretboard .string-name { fill: var(--muted); font-family: system-ui, sans-serif; }
.fretboard .hit { fill: transparent; cursor: pointer; }
.fretboard .hit:hover { fill: rgba(255, 255, 255, .08); }
.fretboard .target { fill: var(--accent); stroke: #0b0b0b; stroke-width: 1; pointer-events: none; }
.fretboard .target.heard { fill: var(--good); }
.fretboard .finger { fill: #0b0b0b; font-weight: 700; pointer-events: none; font-family: system-ui, sans-serif; }
.fretboard .clicked { fill: #fff; stroke: #0b0b0b; stroke-width: 2; pointer-events: none; }
.fretboard .muted-mark { fill: var(--bad); pointer-events: none; }
.heard { color: var(--muted); font-size: 14px; margin: 6px 0 10px; }

.mic-panel { margin-bottom: 16px; }
.mic-row { display: flex; flex-wrap: wrap; align-items: flex-start; gap: 12px 28px; font-size: 14px; }
.mic-control { display: flex; flex-direction: column; gap: 4px; flex: 1 1 220px; max-width: 300px; }
.mic-control small { color: var(--muted); font-size: 12px; line-height: 1.35; }
.mic-control input[type=range] { width: 150px; vertical-align: middle; }
.mic-control span[id$="-val"] { color: var(--muted); font-size: 12px; }
.mic-show { display: inline-flex; align-items: center; gap: 6px; cursor: pointer; align-self: center; }
.meter { width: 150px; height: 8px; background: #101216; border-radius: 4px; overflow: hidden; margin: 6px 0 2px; }
#mic-level { height: 100%; width: 0; background: var(--good); transition: width .05s; }
#mic-canvas { display: block; width: 100%; height: 170px; margin-top: 10px; border-radius: 6px; }

/* ---- Chord grid ---- */
.progress { margin-top: 8px; }
.progress-head { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 10px; }
.chord-grid { display: grid; gap: 2px; overflow-x: auto; font-size: 12px; margin-top: 8px; }
.col-head { text-align: center; color: var(--muted); }
.row-head { color: var(--muted); padding-right: 8px; white-space: nowrap; align-self: center; }
.cell {
  height: 38px; padding: 2px; border-radius: 4px; border: 2px solid transparent;
  display: flex; flex-direction: column; align-items: center; justify-content: center; line-height: 1.15;
  font-size: 12px; opacity: .55;
}
.cell .cell-time { font-size: 10px; font-variant-numeric: tabular-nums; }
.cell.selected { opacity: 1; border-color: var(--text); }
.cell.lvl-0 { background: transparent; border-style: dashed; border-color: var(--border); color: var(--text); }
.cell.lvl-0.selected { border-style: solid; border-color: var(--text); }
.lvl-1 { background: var(--lvl-1); color: #f0efec; }
.lvl-2 { background: var(--lvl-2); color: #f0efec; }
.lvl-3 { background: var(--lvl-3); color: #0b0b0b; }
.lvl-4 { background: var(--lvl-4); color: #0b0b0b; }
.cell.unplayable { opacity: .15; }
.legend { display: flex; flex-wrap: wrap; gap: 6px 16px; margin-top: 12px; font-size: 13px; }
.legend span { display: inline-flex; align-items: center; gap: 6px; }
.swatch { display: inline-block; width: 14px; height: 14px; border-radius: 4px; }
.swatch.lvl-0 { border: 1px dashed var(--border); }
.grid-tip {
  position: fixed; z-index: 10; max-width: 300px; background: #0d0e11; border: 1px solid var(--border);
  border-radius: 6px; padding: 8px 10px; font-size: 13px; white-space: pre-line; pointer-events: none;
}

.options { margin-top: 16px; }
.options-grid { display: flex; flex-wrap: wrap; gap: 10px 24px; align-items: center; margin-top: 8px; }
.options-grid input[type=number] { width: 64px; margin-left: 6px; }
.options-grid select { margin-left: 6px; }

/* ---- Play along ---- */
.play-top { display: grid; grid-template-columns: 3fr 2fr; gap: 16px; }
.play-setup label, .play-options label { display: block; margin: 4px 0 8px; }
.play-setup select { max-width: 100%; margin-left: 6px; }
.play-setup label.block { margin-top: 6px; }
.play-setup textarea { display: block; width: 100%; margin-top: 4px; font-family: ui-monospace, Consolas, monospace; resize: vertical; }
.transpose button { padding: 2px 10px; margin: 0 4px; }
.song-link { display: inline-block; font-size: 14px; color: var(--accent); margin: 0 0 6px; text-decoration: none; }
.song-link:hover { text-decoration: underline; }
.errors { color: var(--warn); font-size: 13px; min-height: 1.2em; margin: 4px 0; }
.play-options select { display: block; margin-top: 4px; max-width: 100%; }
.play-options input[type=range] { width: 150px; vertical-align: middle; }
.bars { display: flex; flex-wrap: wrap; gap: 4px; margin: 16px 0 8px; }
.bar {
  flex: 0 0 calc(25% - 3px); display: flex; gap: 10px; justify-content: space-around;
  border: 1px solid var(--border); border-radius: 6px; padding: 8px; font-size: 18px; font-weight: 600;
}
.bar.current { border-color: var(--accent); background: rgba(106, 168, 255, .1); }
.bar-chord.hit { color: var(--good); }
.bar-chord.late { color: var(--warn); }
.bar-chord.missed { color: var(--bad); text-decoration: line-through; }
.play-stage { display: flex; justify-content: center; align-items: flex-end; gap: 48px; margin-top: 12px; }
.play-stage .label { color: var(--muted); font-size: 13px; text-transform: uppercase; letter-spacing: .5px; margin-bottom: 4px; text-align: center; }
.play-stage .now, .play-stage .next { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.play-stage .chord-name { font-size: 72px; }
.next-name { font-size: 36px; font-weight: 700; color: var(--muted); }
.change-tip { max-width: 240px; min-height: 2.6em; font-size: 13px; color: var(--warn); text-align: center; line-height: 1.35; }
.beat-dots { display: flex; justify-content: center; align-items: center; gap: 10px; margin-top: 14px; min-height: 18px; }
.beat-dot { width: 14px; height: 14px; border-radius: 50%; background: var(--border); }
.beat-dot.one { outline: 1px solid var(--muted); }
.beat-dot.on { background: var(--accent); }
.count-in { color: var(--warn); font-weight: 600; margin-left: 8px; }
#play-feedback { text-align: center; }
.summary { margin-top: 12px; }
.summary-list { margin: 4px 0 0; padding-left: 18px; }
.changes { margin-top: 16px; }
.chord-input { width: 80px; text-align: center; }
.change-row { display: flex; align-items: center; gap: 14px; padding: 6px 0; border-bottom: 1px solid var(--border); }
.change-name { font-weight: 600; min-width: 110px; }
.change-time { font-variant-numeric: tabular-nums; min-width: 50px; }

/* ---- Tuner ---- */
.tuner { max-width: 640px; margin: 20px auto; text-align: center; }
.tuner-target { color: var(--muted); font-size: 18px; min-height: 1.4em; }
.tuner-note { font-size: 96px; font-weight: 700; line-height: 1.1; }
.tuner-note.in-tune { color: var(--good); }
.tuner-meter { position: relative; height: 64px; margin: 18px 0 8px; border-bottom: 2px solid var(--border); }
.tuner-zone { position: absolute; left: 45%; width: 10%; top: 0; bottom: 0; background: rgba(60, 207, 122, .15); border-radius: 4px; }
.tuner-ticks { position: absolute; left: 0; right: 0; bottom: -22px; display: flex; justify-content: space-between; color: var(--muted); font-size: 12px; }
.tuner-needle { position: absolute; left: 50%; top: 0; bottom: 0; width: 4px; margin-left: -2px; background: var(--warn); border-radius: 2px; transition: left .12s; }
.tuner-needle.in-tune { background: var(--good); }
.tuner-needle.idle { opacity: .2; }
.tuner-cents { margin-top: 30px; font-size: 18px; min-height: 1.4em; }
.tuner-strings { display: flex; justify-content: center; gap: 6px; margin: 16px 0; flex-wrap: wrap; }
.tuner-strings .near { border-color: var(--good); color: var(--good); }

.tip { color: var(--muted); font-size: 13px; margin-top: 20px; }
.storage-note { color: var(--muted); font-size: 12px; margin: 6px 0 0; opacity: .8; }
kbd { background: var(--panel); border: 1px solid var(--border); border-radius: 4px; padding: 0 5px; font-size: 12px; }

@media (max-width: 800px) {
  main { padding: 16px; }
  .play-top { grid-template-columns: 1fr; }
  .chord-name { font-size: 64px; }
  .bar { flex-basis: calc(50% - 2px); }
  .stage { gap: 20px; }
}

.calib-status { color: var(--warn) !important; }
.calib-status:empty { display: none; }
#mic-calibrate { align-self: flex-start; margin-top: 2px; }

/* Let the play-along panels shrink to a phone's width (grid items otherwise keep their widest
   content's width, such as a long option in the mode menu). */
.play-top > * { min-width: 0; }
.play-setup select, .play-options select { width: 100%; max-width: 100%; margin-left: 0; }
.play-setup textarea { max-width: 100%; }

/* ---- Your chords ---- */
.sel-summary { margin: 6px 0 4px; font-size: 14px; line-height: 1.5; }
.set-group { margin-top: 14px; }
.set-group h3, .grid-head h3 { font-size: 14px; margin: 0; color: var(--text); }
.set-group .note { margin: 2px 0 8px; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip { display: inline-flex; align-items: center; gap: 6px; border-radius: 999px; padding: 4px 12px; font-size: 13px; }
.chip-mark { width: 1em; text-align: center; color: var(--muted); }
.chip-count { font-size: 11px; color: var(--muted); background: var(--bg); border-radius: 999px; padding: 0 6px; }
.chip.on { border-color: var(--accent); color: var(--accent); background: rgba(106, 168, 255, .12); }
.chip.on .chip-mark { color: var(--accent); }
.chip.partial { border-color: var(--accent); border-style: dashed; }
#sel-prog { max-width: 100%; }
.grid-head { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.grid-head label { font-size: 13px; color: var(--muted); display: inline-flex; gap: 6px; align-items: center; cursor: pointer; }