:root {
  /* neutrals — warm editorial paper */
  --bg: #f6f5f2;
  --panel: #ffffff;
  --panel-2: #f1f0ec;
  --line: #e7e6e2;
  --line-2: #dcdad4;
  --text: #16151a;
  --muted: #6b6a72;
  --muted-2: #9a988f;
  /* accent — black ink, used sparingly */
  --accent: #16151a;
  --accent-2: #2a2830;
  --accent-ink: #16151a;
  --accent-weak: #ecebe7;
  --accent-ring: rgba(20, 18, 26, .16);
  --grad: linear-gradient(135deg, #1c1b21 0%, #35333c 100%);
  --warn: #d8455d;
  /* depth — soft single shadow, no glows */
  --shadow-sm: 0 1px 2px rgba(20, 18, 30, .04);
  --shadow: 0 1px 1px rgba(20, 18, 30, .035), 0 10px 24px -16px rgba(20, 18, 30, .14);
  --shadow-lg: 0 20px 50px -24px rgba(20, 18, 30, .22);
  --r: 14px;
  --r-sm: 10px;
  /* editorial display face for headings; Geist stays the UI/body face */
  --font-display: 'Fraunces', 'Georgia', 'Times New Roman', serif;
}

* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  font-family: 'Geist', system-ui, -apple-system, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  letter-spacing: -0.011em;
}
.mono { font-family: 'Geist Mono', ui-monospace, monospace; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
button, input, select, textarea { font-family: inherit; }

.app { display: grid; grid-template-columns: 296px 1fr; min-height: 100vh; transition: grid-template-columns .26s ease; }
.app.nav-collapsed { grid-template-columns: 60px 1fr; }
.nav-backdrop { display: none; }

/* ---------------------------- Sidebar ---------------------------- */
.sidebar {
  background: rgba(255, 255, 255, .85);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-right: 1px solid var(--line);
  padding: 22px 16px 104px;
  display: flex; flex-direction: column; gap: 18px;
  position: sticky; top: 0; height: 100vh; overflow: hidden auto;
  min-width: 0;
}
.nav-close { display: none; }

/* sidebar collapse handle — lives on the sidebar itself (desktop rail toggle) */
.rail-toggle {
  position: absolute; top: 16px; right: 12px; z-index: 6;
  width: 32px; height: 32px; border-radius: 9px; cursor: pointer;
  border: 1px solid var(--line); background: var(--panel); color: var(--muted);
  font-size: 19px; line-height: 1; display: grid; place-items: center;
  transition: color .12s, border-color .12s;
}
.rail-toggle:hover { color: var(--accent-ink); border-color: var(--accent); }
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 46px; height: 46px; flex: 0 0 auto;
  display: grid; place-items: center;
}
.brand-logo { width: 100%; height: 100%; object-fit: contain; display: block; }
.brand-title { font-family: var(--font-display); font-weight: 600; font-size: 19px; letter-spacing: -.01em; }
.brand-sub { font-size: 11.5px; color: var(--muted); letter-spacing: .02em; }
.search-hint { font-size: 11px; text-transform: uppercase; letter-spacing: .14em; color: var(--muted-2); }

.nav { display: flex; flex-direction: column; gap: 8px; }
.section { display: flex; flex-direction: column; gap: 6px; }
.section-head {
  appearance: none; text-align: left;
  display: flex; align-items: center; gap: 11px; width: 100%;
  cursor: pointer; user-select: none; font-family: inherit; color: var(--text);
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 13px; padding: 9px 13px; box-shadow: var(--shadow-sm);
  transition: border-color .12s, box-shadow .12s;
}
.section-head:hover { border-color: var(--accent); }
.sec-ico { display: flex; align-items: center; color: var(--muted-2); }
.section-head:hover .sec-ico { color: var(--accent-ink); }
.sec-label { font-size: 14px; font-weight: 600; letter-spacing: -.01em; }
.sec-caret { color: var(--muted-2); font-size: 10px; margin-left: auto; transition: transform .2s; }
.section.open > .section-head .sec-caret { transform: rotate(180deg); }
.section-body { display: none; flex-direction: column; gap: 6px; padding: 4px 2px 8px; }
.section.open > .section-body { display: flex; }

.cat { border-radius: 12px; }
.cat-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 13px; cursor: pointer; user-select: none;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--r-sm); font-weight: 550; font-size: 14px;
  box-shadow: var(--shadow-sm);
  transition: border-color .15s, box-shadow .15s, transform .06s;
}
.cat-head:hover { border-color: var(--line-2); box-shadow: var(--shadow); }
.cat-head:active { transform: translateY(.5px); }
.cat-head .chev { color: var(--muted-2); transition: transform .2s; font-size: 10px; }
.cat.open .cat-head .chev { transform: rotate(90deg); }
.cat-body { display: none; padding: 8px 2px 4px; }
.cat.open > .cat-body { display: block; }

.subgroup-label { font-size: 11px; color: var(--muted-2); text-transform: uppercase; letter-spacing: .1em; margin: 10px 4px 6px; }
.keys { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; }
.key {
  appearance: none; border: 1px solid var(--line); background: var(--panel);
  color: var(--text); padding: 9px 0; border-radius: 9px; cursor: pointer;
  font-size: 13px; font-weight: 550; text-align: center;
  transition: all .12s;
}
.key:hover { border-color: var(--accent); color: var(--accent-ink); transform: translateY(-1px); }
.key.active { background: var(--grad); color: #fff; border-color: transparent; box-shadow: 0 8px 18px -6px var(--accent-ring); }
.tune-list { display: flex; flex-direction: column; gap: 6px; }
.key.tune { grid-column: auto; text-align: left; padding: 11px 13px; font-size: 13px; }

.sidebar-foot {
  margin-top: auto; font-size: 11px; line-height: 1.65; color: var(--muted-2);
  border-top: 1px solid var(--line); padding-top: 14px;
}

/* ---------------------------- Content ---------------------------- */
.content { padding: 30px 46px 160px; max-width: 1140px; }

/* fixed transport bar pinned to the bottom of the viewport (desktop + mobile) */
.transport-bar {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 60;
  display: flex; align-items: center; justify-content: center;
  gap: 16px; flex-wrap: wrap;
  padding: 12px clamp(14px, 4vw, 40px);
  background: rgba(246, 245, 242, .86);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  border-top: 1px solid var(--line);
  box-shadow: 0 -10px 30px -16px rgba(40, 30, 90, .28);
}
.metro {
  display: flex; align-items: center; gap: 16px;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 16px; padding: 10px 18px; box-shadow: var(--shadow);
}
/* bottom-bar: the primary play/stop button + what it targets */
.transport-main {
  display: flex; align-items: center; gap: 12px;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 16px; padding: 9px 16px 9px 9px; box-shadow: var(--shadow);
}
.transport-play {
  width: 46px; height: 46px; border-radius: 50%; cursor: pointer; border: none;
  font-size: 15px; color: #fff; background: var(--grad); display: grid; place-items: center;
  transition: transform .08s, box-shadow .14s;
  box-shadow: 0 8px 18px -6px var(--accent-ring), inset 0 1px 0 rgba(255, 255, 255, .3);
}
.transport-play:active { transform: scale(.93); }
.transport-play.pulse { box-shadow: 0 0 0 5px var(--accent-ring), 0 8px 18px -6px var(--accent-ring); }
.transport-play.playing { background: var(--warn); }
.transport-focus { display: flex; flex-direction: column; line-height: 1.15; min-width: 96px; max-width: 240px; }
.transport-cap { font-size: 9.5px; text-transform: uppercase; letter-spacing: .14em; color: var(--muted-2); font-weight: 600; }
.transport-focus-label { font-size: 14px; font-weight: 600; letter-spacing: -.01em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* metronome is now a secondary icon toggle (lights up when on) */
.metro-btn {
  width: 42px; height: 42px; border-radius: 50%; cursor: pointer;
  border: 1px solid var(--line); color: var(--muted); background: var(--panel);
  display: grid; place-items: center;
  transition: transform .08s, box-shadow .14s, background .14s, color .14s, border-color .14s;
}
.metro-btn svg { width: 21px; height: 21px; }
.metro-btn:hover { border-color: var(--accent); color: var(--accent-ink); }
.metro-btn:active { transform: scale(.93); }
.metro-btn.pulse { box-shadow: 0 0 0 5px var(--accent-ring); }
.metro-btn.on { background: var(--warn); color: #fff; border-color: transparent; box-shadow: var(--shadow-sm); }
.metro-readout { display: flex; flex-direction: column; gap: 5px; min-width: 200px; }
.metro-bpm { display: flex; align-items: baseline; gap: 6px; font-weight: 700; font-size: 23px; font-family: 'Geist Mono', monospace; }
.metro-unit { font-size: 11px; font-weight: 600; color: var(--muted); letter-spacing: .12em; font-family: 'Geist', sans-serif; }
.bpm-range { -webkit-appearance: none; appearance: none; width: 100%; height: 5px; border-radius: 5px; background: var(--line-2); outline: none; }
.bpm-range::-webkit-slider-thumb { -webkit-appearance: none; width: 17px; height: 17px; border-radius: 50%; background: var(--accent); cursor: pointer; border: 3px solid #fff; box-shadow: 0 1px 5px rgba(40, 30, 90, .3); }
.bpm-range::-moz-range-thumb { width: 17px; height: 17px; border-radius: 50%; background: var(--accent); cursor: pointer; border: 3px solid #fff; }
.beat-dots { display: flex; gap: 7px; }
.beat-dots span { width: 9px; height: 9px; border-radius: 50%; background: var(--line-2); transition: background .05s, transform .05s; }
.beat-dots span.on { background: var(--accent); transform: scale(1.35); }
.beat-dots span.on.accent { background: var(--warn); }

/* note-value + swing menu */
.feel { position: relative; }
.feel-btn {
  display: flex; align-items: center; gap: 7px; cursor: pointer;
  font-family: inherit; font-weight: 600; font-size: 13px; color: var(--text);
  background: var(--panel-2); border: 1px solid var(--line);
  border-radius: 11px; padding: 9px 13px; transition: all .12s;
}
.feel-btn:hover { border-color: var(--accent); color: var(--accent-ink); }
.feel-ico { color: var(--accent); font-size: 14px; }
.feel-caret { color: var(--muted-2); font-size: 10px; }
.feel-menu {
  position: absolute; bottom: calc(100% + 10px); right: 0; z-index: 70;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 14px; padding: 12px; box-shadow: var(--shadow-lg);
  width: 232px;
}
.feel-menu[hidden] { display: none; }
.feel-group-label { font-size: 10.5px; text-transform: uppercase; letter-spacing: .12em; color: var(--muted-2); font-weight: 600; margin: 4px 2px 7px; }
.feel-group-label:not(:first-child) { margin-top: 12px; }
.feel-row { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.feel-row button {
  appearance: none; border: 1px solid var(--line); cursor: pointer;
  font-family: inherit; font-weight: 550; font-size: 13px; color: var(--text);
  background: var(--panel); padding: 9px 8px; border-radius: 9px; transition: all .12s;
}
.feel-row button:hover:not(:disabled) { border-color: var(--accent); color: var(--accent-ink); }
.feel-row button.active { background: var(--grad); color: #fff; border-color: transparent; }
.feel-row button:disabled { opacity: .4; cursor: not-allowed; }

/* instrument dropdown (sits at the top of the sidebar) */
.inst-select { position: relative; }
.inst-btn {
  display: flex; align-items: center; gap: 11px; cursor: pointer; width: 100%;
  font-family: inherit; color: var(--text);
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 13px; padding: 9px 13px; box-shadow: var(--shadow-sm);
  transition: border-color .12s, box-shadow .12s;
}
.inst-btn:hover { border-color: var(--accent); }
.inst-ico { display: flex; align-items: center; }
.inst-ico .inst-emoji { font-size: 20px; line-height: 1; }
.inst-img { width: 28px; height: 28px; object-fit: contain; display: block; flex: 0 0 auto; }
.inst-emoji { line-height: 1; }
.inst-text { display: flex; flex-direction: column; align-items: flex-start; line-height: 1.15; }
.inst-cap { font-size: 9.5px; text-transform: uppercase; letter-spacing: .14em; color: var(--muted-2); font-weight: 600; }
.inst-label { font-size: 14px; font-weight: 600; letter-spacing: -.01em; }
.inst-caret { color: var(--muted-2); font-size: 10px; margin-left: auto; }
.inst-menu {
  position: absolute; top: calc(100% + 8px); left: 0; right: 0; z-index: 70;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 14px; padding: 10px; box-shadow: var(--shadow-lg);
  max-height: 56vh; overflow-y: auto;
  display: grid; grid-template-columns: 1fr; gap: 4px;
}
.inst-menu[hidden] { display: none; }
.inst-group-label {
  grid-column: 1 / -1; font-size: 10px; text-transform: uppercase; letter-spacing: .12em;
  color: var(--muted-2); font-weight: 600; margin: 8px 2px 2px;
}
.inst-group-label:first-child { margin-top: 2px; }
.inst-menu button {
  appearance: none; border: 1px solid var(--line); cursor: pointer;
  font-family: inherit; font-weight: 550; font-size: 13px; color: var(--text);
  background: var(--panel); padding: 7px 11px; border-radius: 10px; transition: all .12s;
  display: flex; align-items: center; gap: 10px; text-align: left;
}
.inst-opt-label { flex: 1; min-width: 0; }
.inst-menu button:hover { border-color: var(--accent); color: var(--accent-ink); }
.inst-menu button.active { background: var(--grad); color: #fff; border-color: transparent; }

/* "Next scale" stepper in the transport bar */
.skip-control {
  display: flex; align-items: center; gap: 6px;
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 16px; padding: 6px; box-shadow: var(--shadow);
}
.skip-btn {
  appearance: none; cursor: pointer; font-family: inherit; font-weight: 600; font-size: 13px;
  color: var(--text); background: var(--panel-2); border: 1px solid var(--line);
  height: 40px; padding: 0 12px; border-radius: 11px; transition: all .12s; white-space: nowrap;
}
.skip-btn:hover { border-color: var(--accent); color: var(--accent-ink); transform: translateY(-1px); }
.skip-btn.skip-next { background: var(--grad); color: #fff; border-color: transparent; padding: 0 16px; }
.skip-btn.skip-next:hover { box-shadow: 0 8px 18px -6px var(--accent-ring); color: #fff; }

/* one-bar count-in overlay (4·3·2·1) */
.count-in {
  position: fixed; left: 50%; top: 44%; transform: translate(-50%, -50%);
  z-index: 90; pointer-events: none; opacity: 0;
  font-family: 'Geist Mono', monospace; font-weight: 700; font-size: clamp(96px, 22vw, 200px);
  line-height: 1; color: #fff; text-shadow: 0 12px 40px var(--accent-ring);
  -webkit-text-stroke: 2px var(--accent);
}
.count-in.show { animation: countpop .58s ease-out forwards; }
@keyframes countpop {
  0%   { opacity: 0; transform: translate(-50%, -50%) scale(.55); }
  22%  { opacity: 1; transform: translate(-50%, -50%) scale(1.05); }
  70%  { opacity: 1; transform: translate(-50%, -50%) scale(1); }
  100% { opacity: 0; transform: translate(-50%, -50%) scale(.92); }
}

.topbar { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; flex-wrap: wrap; margin-bottom: 26px; padding-top: 6px; }
.topbar-left { display: flex; align-items: flex-start; gap: 14px; min-width: 0; }
.nav-toggle {
  flex: none; appearance: none; cursor: pointer; margin-top: 2px;
  width: 42px; height: 42px; border-radius: 12px;
  border: 1px solid var(--line); background: var(--panel); color: var(--text);
  font-size: 18px; line-height: 1; display: grid; place-items: center;
  box-shadow: var(--shadow-sm); transition: border-color .12s, color .12s, transform .08s;
}
.nav-toggle:hover { border-color: var(--accent); color: var(--accent-ink); }
.nav-toggle:active { transform: translateY(1px); }
.scale-title { font-family: var(--font-display); font-size: 44px; font-weight: 500; letter-spacing: -.015em; line-height: 1.02; }
.scale-meta { color: var(--muted); font-size: 14px; margin-top: 10px; }
.scale-meta .pill { display: inline-flex; align-items: center; background: transparent; color: var(--muted); border: 1px solid var(--line-2); padding: 3px 11px; border-radius: 999px; font-size: 11.5px; font-weight: 600; letter-spacing: .01em; margin-right: 8px; }

.toggles { display: flex; gap: 9px; flex-wrap: wrap; max-width: 640px; justify-content: flex-end; }
.toggle {
  appearance: none; cursor: pointer; font-family: inherit; font-weight: 550;
  font-size: 12.5px; color: var(--text); background: var(--panel);
  border: 1px solid var(--line); padding: 9px 14px; border-radius: 999px;
  box-shadow: var(--shadow-sm); transition: all .14s;
}
.toggle:hover { border-color: var(--accent); color: var(--accent-ink); transform: translateY(-1px); }
.toggle.on { background: var(--grad); color: #fff; border-color: transparent; box-shadow: 0 8px 18px -6px var(--accent-ring); }

.notes-line { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 22px; }
.note-chip { font-weight: 600; font-size: 14px; color: var(--text); background: var(--panel); border: 1px solid var(--line); padding: 7px 13px; border-radius: 9px; box-shadow: var(--shadow-sm); }
.note-chip:first-child { border-color: transparent; color: #fff; background: var(--grad); }

.sheet-stack { display: flex; flex-direction: column; gap: 18px; }
#variantSheets { display: flex; flex-direction: column; gap: 18px; }
.sheet { background: var(--panel); border: 1px solid var(--line); border-radius: var(--r); padding: 16px 18px 12px; box-shadow: var(--shadow); transition: border-color .14s, box-shadow .14s; }
.sheet.hidden { display: none; }
.sheet.focused { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-ring), var(--shadow); }
.focus-card { cursor: pointer; }
.focus-card:hover:not(.focused) { border-color: var(--line-2); box-shadow: var(--shadow), 0 0 0 1px var(--line-2); }
.sheet-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; gap: 12px; cursor: pointer; user-select: none; }
.sheet-label { font-size: 12px; text-transform: uppercase; letter-spacing: .11em; color: var(--muted); font-weight: 600; }
.sheet-head::after {
  content: 'Tap to focus'; font-size: 10px; font-weight: 600; letter-spacing: .04em;
  text-transform: none; color: var(--muted-2); white-space: nowrap; transition: color .14s;
}
.sheet-head:hover::after { color: var(--accent-ink); }
.sheet.focused .sheet-head::after { content: '▶ in focus'; color: var(--accent); }
.sheet.playing .sheet-head::after { content: '♫ playing'; color: var(--accent); }
.play {
  appearance: none; cursor: pointer; font-family: inherit; font-weight: 600;
  font-size: 13px; color: var(--accent-ink); background: var(--accent-weak);
  border: 1px solid var(--line-2); padding: 9px 18px; border-radius: 999px;
  white-space: nowrap; transition: all .12s;
}
.play:hover { background: #e7e9ff; transform: translateY(-1px); }
.play.playing { background: var(--grad); color: #fff; border-color: transparent; box-shadow: 0 8px 18px -6px var(--accent-ring); }

.paper { background: #ffffff; border: 1px solid var(--line); border-radius: 12px; padding: 8px 4px; overflow-x: auto; }
.paper svg { display: block; }

/* ---------------------------- Lead sheet ---------------------------- */
.leadsheet-wrap { overflow-x: auto; }
.leadsheet { display: flex; flex-direction: column; gap: 12px; min-width: 520px; }
.ls-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.ls-bar { display: flex; align-items: stretch; gap: 6px; border: 1px solid var(--line-2); border-radius: 14px; background: var(--panel-2); min-height: 76px; padding: 6px; }
.chord-cell { flex: 1; display: grid; place-items: center; font-weight: 700; font-size: 25px; letter-spacing: -.02em; color: var(--text); border-radius: 10px; transition: all .12s; padding: 4px; }
.chord-cell.half { font-size: 18px; }
.chord-cell.now { background: var(--grad); color: #fff; box-shadow: 0 8px 18px -6px var(--accent-ring); transform: translateY(-1px); }

/* ---------------------------- Randomizer ---------------------------- */
.rand-body { display: flex; flex-direction: column; gap: 18px; }
.rand-controls { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.rand-ctl-label { font-size: 12px; text-transform: uppercase; letter-spacing: .11em; color: var(--muted); font-weight: 600; }
.bars-select { display: inline-flex; gap: 4px; background: var(--panel-2); border: 1px solid var(--line); border-radius: 12px; padding: 5px; }
.bars-select button {
  appearance: none; border: none; cursor: pointer; font-family: 'Geist Mono', monospace;
  font-weight: 600; font-size: 14px; color: var(--text); background: transparent;
  width: 38px; height: 36px; border-radius: 9px; transition: all .12s;
}
.bars-select button:hover { background: var(--panel); }
.bars-select button.active { background: var(--grad); color: #fff; }

.rand-stage {
  display: grid; grid-template-columns: 1fr auto; gap: 18px; align-items: stretch;
  background: linear-gradient(135deg, #faf9ff, #f3f1fb);
  border: 1px solid var(--line); border-radius: var(--r); padding: 26px 28px;
}
.rand-cap { font-size: 11px; text-transform: uppercase; letter-spacing: .14em; color: var(--muted-2); font-weight: 600; margin-bottom: 8px; }
.rand-now {
  font-family: 'Geist Mono', monospace; font-weight: 700; letter-spacing: -.03em;
  font-size: clamp(48px, 9vw, 84px); line-height: 1;
  background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent;
}
.rand-now.flash { animation: pop .35s cubic-bezier(.2, .9, .3, 1); }
@keyframes pop { 0% { transform: scale(.86); opacity: .3; } 100% { transform: scale(1); opacity: 1; } }
.rand-scale { margin-top: 12px; font-size: 14px; color: var(--muted); font-weight: 500; }
.rand-next-wrap { display: flex; flex-direction: column; justify-content: center; border-left: 1px dashed var(--line-2); padding-left: 22px; min-width: 130px; }
.rand-next { font-family: 'Geist Mono', monospace; font-weight: 600; font-size: 30px; color: var(--text); letter-spacing: -.02em; }
.rand-progress { height: 8px; border-radius: 8px; background: var(--line-2); overflow: hidden; --p: 0%; }
.rand-progress::after { content: ''; display: block; height: 100%; width: var(--p); background: var(--grad); border-radius: 8px; transition: width .06s linear; }

/* ---------------------------- Improv builder ---------------------------- */
.builder-body { display: flex; flex-direction: column; gap: 22px; }
.builder-pick { display: flex; flex-direction: column; gap: 16px; }
.builder-field { display: flex; flex-direction: column; gap: 8px; }
.builder-field .rand-cap em { font-style: normal; color: var(--muted); text-transform: none; letter-spacing: 0; }
.builder-roots, .builder-quals { display: flex; flex-wrap: wrap; gap: 6px; }
.builder-roots button, .builder-quals button {
  appearance: none; cursor: pointer; font-family: 'Geist Mono', monospace;
  font-weight: 600; font-size: 14px; color: var(--text);
  background: var(--panel-2); border: 1px solid var(--line);
  min-width: 44px; height: 38px; padding: 0 12px; border-radius: 10px; transition: all .12s;
}
.builder-roots button:hover, .builder-quals button:hover { background: var(--panel); transform: translateY(-1px); }
.builder-roots button.active, .builder-quals button.active { background: var(--grad); color: #fff; border-color: transparent; }
.builder-actions { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.builder-add {
  appearance: none; cursor: pointer; font-family: inherit;
  font-weight: 650; font-size: 14px; color: #fff; background: var(--grad);
  border: none; padding: 11px 20px; border-radius: 12px; transition: all .12s;
  box-shadow: 0 8px 18px -6px var(--accent-ring);
}
.builder-add:hover { transform: translateY(-1px); }
.builder-preview {
  appearance: none; cursor: pointer; font-family: inherit; font-weight: 600; font-size: 14px;
  color: var(--accent-ink); background: var(--panel-2); border: 1px solid var(--line);
  padding: 11px 18px; border-radius: 12px; transition: all .12s;
}
.builder-preview:hover { border-color: var(--accent); transform: translateY(-1px); }
.builder-preview:active { transform: translateY(0) scale(.97); }

.builder-seq-cap { display: flex; align-items: center; justify-content: space-between; }
.builder-clear {
  appearance: none; cursor: pointer; font-family: inherit; font-weight: 600; font-size: 11px;
  letter-spacing: .04em; text-transform: uppercase; color: var(--muted);
  background: transparent; border: 1px solid var(--line); padding: 5px 11px; border-radius: 8px; transition: all .12s;
}
.builder-clear:hover { color: var(--text); background: var(--panel-2); }
.builder-seq { display: flex; flex-wrap: wrap; gap: 10px; }
.builder-empty { color: var(--muted); font-size: 14px; padding: 18px 4px; }
.chord-cell.builder-chip {
  flex: 0 0 auto; display: flex; flex-direction: column; align-items: center; gap: 4px;
  min-width: 96px; padding: 12px 14px 10px; border: 1px solid var(--line-2);
  background: var(--panel-2); border-radius: 14px; cursor: pointer;
  transition: border-color .12s, transform .08s, box-shadow .12s;
}
.builder-chip:hover:not(.now) { border-color: var(--accent); }
.builder-chip:active { transform: scale(.97); }
.builder-chip.lit:not(.now) { border-color: var(--accent); box-shadow: 0 6px 16px -8px var(--accent-ring); animation: chiplit .35s ease-out; }
@keyframes chiplit { 0% { transform: scale(1.04); } 100% { transform: scale(1); } }
.builder-chip .bc-sym { font-size: 24px; font-weight: 700; letter-spacing: -.02em; }
.builder-chip .bc-dur { font-size: 11px; font-weight: 600; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; }
.builder-chip.now .bc-dur { color: rgba(255, 255, 255, .85); }
.builder-chip .bc-ctl { display: flex; gap: 4px; margin-top: 4px; }
.builder-chip .bc-btn {
  appearance: none; cursor: pointer; font-family: 'Geist Mono', monospace; font-size: 12px; line-height: 1;
  color: var(--muted); background: var(--panel); border: 1px solid var(--line);
  width: 24px; height: 22px; border-radius: 7px; transition: all .12s;
}
.builder-chip .bc-btn:hover:not(:disabled) { color: var(--text); transform: translateY(-1px); }
.builder-chip .bc-btn:disabled { opacity: .35; cursor: default; }
.builder-chip .bc-rm { color: var(--accent-ink); }
.builder-chip.now .bc-btn { background: rgba(255, 255, 255, .2); border-color: transparent; color: #fff; }

/* ---- exercise builder ---- */
.ex-deg-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.chord-cell.ex-note-chip { min-width: 64px; padding: 9px 10px 8px; }
.ex-note-chip .bc-sym { font-size: 19px; }
.chord-cell.ex-step-chip { align-items: flex-start; min-width: 150px; text-align: left; }
.ex-step-chip .bc-sym { font-size: 16px; }
.ex-step-chip .bc-dur { text-transform: none; letter-spacing: .02em; }
.ex-phase-cap { font-size: 11px; font-weight: 700; letter-spacing: .08em; color: var(--accent-ink); text-transform: uppercase; }
.chord-cell.ex-step-chip.sel { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-ring); }
.ex-editor { display: flex; flex-direction: column; gap: 16px; border-top: 1px dashed var(--line-2); margin-top: 16px; padding-top: 16px; }
.ex-editor[hidden] { display: none; }
.ex-staff { display: flex; flex-direction: column; gap: 16px; margin-top: 18px; }
.ex-step-block { display: flex; flex-direction: column; gap: 6px; }
.ex-step-label { font-size: 12px; font-weight: 700; letter-spacing: .02em; color: var(--muted); }
.ex-step-block .paper { margin: 0; }

/* desktop: collapse the sidebar to a slim rail, toggled by its own handle */
@media (min-width: 881px) {
  .nav-toggle { display: none; }                 /* topbar hamburger is mobile-only */
  .app.nav-collapsed > .sidebar { padding: 0; overflow: hidden; }
  .app.nav-collapsed .brand,
  .app.nav-collapsed .inst-select,
  .app.nav-collapsed .search-hint,
  .app.nav-collapsed #nav,
  .app.nav-collapsed .sidebar-foot { display: none; }
  .app.nav-collapsed .rail-toggle { left: 0; right: 0; margin-inline: auto; }
}

@media (max-width: 880px) {
  /* single column; the sidebar becomes an off-canvas drawer over the content */
  .app, .app.nav-collapsed { grid-template-columns: 1fr; transition: none; }
  .rail-toggle { display: none; }                /* mobile uses the topbar hamburger + ✕ */
  .sidebar {
    position: fixed; top: 0; left: 0; height: 100vh; width: min(86vw, 320px);
    z-index: 80; padding-bottom: 24px;
    transform: translateX(0); transition: transform .28s ease;
    box-shadow: 0 0 50px -10px rgba(40, 30, 90, .35);
  }
  .app.nav-collapsed > .sidebar { transform: translateX(-100%); border-right-color: var(--line); }
  .nav-backdrop {
    display: block; position: fixed; inset: 0; z-index: 70; background: rgba(20, 16, 40, .42);
    opacity: 0; pointer-events: none; transition: opacity .28s ease;
  }
  .app:not(.nav-collapsed) ~ .nav-backdrop { opacity: 1; pointer-events: auto; }
  .nav-close {
    display: grid; place-items: center; margin-left: auto; flex: none; cursor: pointer;
    width: 34px; height: 34px; border-radius: 9px; font-size: 14px;
    border: 1px solid var(--line); background: var(--panel); color: var(--muted);
  }
  .nav-close:hover { color: var(--text); border-color: var(--accent); }
  .content { padding: 18px 18px 160px; }
  .scale-title { font-size: 28px; }
  .toggles { justify-content: flex-start; }
  .sheet { padding: 14px 12px 10px; }
  .paper { overflow-x: hidden; }
  .leadsheet { min-width: 0; }
  .ls-row { grid-template-columns: repeat(2, 1fr); gap: 8px; }
  .ls-bar { min-height: 62px; padding: 5px; }
  .chord-cell { font-size: 19px; }
  .chord-cell.half { font-size: 14px; }
  .rand-stage { grid-template-columns: 1fr; }
  .rand-next-wrap { border-left: none; border-top: 1px dashed var(--line-2); padding-left: 0; padding-top: 16px; }
}

/* keep the transport bar usable on phones: compact metro card, full-width rows */
@media (max-width: 560px) {
  .transport-bar { gap: 10px; padding: 10px 12px; }
  .transport-main { flex: 1 1 100%; }
  .transport-focus { flex: 1; max-width: none; }
  .metro { gap: 11px; padding: 9px 13px; flex: 1 1 100%; justify-content: space-between; }
  .metro-readout { min-width: 0; flex: 1; }
  .beat-dots { display: none; }            /* save width; the metro button still pulses the beat */
  .skip-control { flex: 1 1 100%; justify-content: center; }
}