*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #121110;
  --surface: #1b1917;
  --surface2: #242119;
  --border: rgba(236,230,217,0.09);
  --border2: rgba(236,230,217,0.16);
  --text: #ece6d9;
  --muted: #98937f;
  --hint: #6d6857;
  --accent: #c2a05e;
  --accent-text: #191307;
  --key-bg: #f1ecdf;
  --key-black: #16161b;
  --font: -apple-system, 'SF Pro Display', system-ui, sans-serif;
  --serif: ui-serif, 'New York', Georgia, serif;
}

html[data-theme="light"] {
  --bg: #f5f1e6;
  --surface: #fffcf3;
  --surface2: #ece5d4;
  --border: rgba(38,34,24,0.10);
  --border2: rgba(38,34,24,0.18);
  --text: #262218;
  --muted: #6f6858;
  --hint: #a49b85;
  --accent: #8f7434;
  --accent-text: #fffcf3;
  --key-bg: #fbf8ef;
  --key-black: #2a2a30;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.6;
  min-height: 100vh;
  padding: 0 0 4rem;
  -webkit-text-size-adjust: 100%;
  transition: background 0.2s, color 0.2s;
}

button, input { font: inherit; }
button { cursor: pointer; -webkit-tap-highlight-color: transparent; }
button:focus-visible, input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}

.scale-notes, .prog-name, .prog-chords, .chord-box-deg, .chord-box-name, .chord-notes,
.degree-name, .degree-chord, .alt-sym, .alt-formula, .interval-box, .interval-step,
.vc-label, .cc-lab, .cc-mark, .neck-dot, .neck-string, .wkey, .bkey {
  font-variant-numeric: tabular-nums;
}
header h1, .scale-title, .allchords-head > span:first-child, .altref-head > span:first-child {
  font-family: var(--serif);
}

/* ── header ── */
header {
  padding: 2.5rem 1.5rem 2rem;
  border-bottom: 0.5px solid var(--border);
  max-width: 720px; margin: 0 auto;
  position: relative;
}
.header-eyebrow {
  font-family: var(--font); font-size: 11px; letter-spacing: 0.12em;
  color: var(--accent); text-transform: uppercase; margin-bottom: 0.5rem;
}
header h1 {
  font-size: clamp(26px, 6vw, 42px); font-weight: 600;
  letter-spacing: -0.02em; line-height: 1.15; color: var(--text);
}
header p { margin-top: 0.6rem; font-size: 14px; color: var(--muted); max-width: 480px; }
.header-actions {
  position: absolute; top: 2.5rem; right: 1.5rem; display: flex; gap: 8px;
}
.icon-btn {
  width: 40px; height: 40px; border-radius: 10px;
  border: 0.5px solid var(--border2); background: var(--surface);
  color: var(--text); font-size: 16px; line-height: 1;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.15s, border-color 0.15s;
}
.icon-btn:hover { border-color: var(--accent); }

/* ── segmented selectors (tonica / strumento) ── */
.seg-wrap { max-width: 720px; margin: 0 auto; padding: 1rem 1.5rem 0.25rem; }
.seg-label {
  font-family: var(--font); font-size: 10px; letter-spacing: 0.1em;
  color: var(--hint); text-transform: uppercase; margin-bottom: 8px;
}
.seg-scroll {
  display: flex; gap: 6px; overflow-x: auto;
  -webkit-overflow-scrolling: touch; padding-bottom: 4px; scrollbar-width: none;
}
.seg-scroll::-webkit-scrollbar { display: none; }
.seg-btn {
  font-family: var(--font); font-size: 12px; font-weight: 700;
  min-width: 40px; height: 40px; padding: 0 12px; border-radius: 10px;
  border: 0.5px solid var(--border2); background: var(--surface);
  color: var(--muted); flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.seg-btn:hover { color: var(--text); }
.seg-btn.on { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }

/* ── search ── */
.search-wrap { max-width: 720px; margin: 0 auto; padding: 0.75rem 1.5rem 0.25rem; }
.search-input {
  width: 100%; min-height: 42px; border-radius: 10px;
  border: 0.5px solid var(--border2); background: var(--surface);
  color: var(--text); font-size: 14px; padding: 9px 12px;
}
.search-input::placeholder { color: var(--hint); }

/* ── filter bar ── */
.filter-wrap {
  position: -webkit-sticky; position: sticky; top: 0; z-index: 10;
  background: var(--bg); border-bottom: 0.5px solid var(--border);
  padding: 0.75rem 1.5rem;
}
.filter-inner {
  max-width: 720px; margin: 0 auto; display: flex; gap: 6px;
  flex-wrap: nowrap; overflow-x: auto; -webkit-overflow-scrolling: touch;
  padding-bottom: 2px; scrollbar-width: none;
}
.filter-inner::-webkit-scrollbar { display: none; }
.filter-btn {
  font-family: var(--font); font-size: 11px; letter-spacing: 0.04em;
  padding: 5px 14px; border-radius: 99px; border: 0.5px solid var(--border2);
  background: transparent; color: var(--muted); white-space: nowrap;
  flex-shrink: 0; transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.filter-btn:hover { color: var(--text); border-color: var(--border2); }
.filter-btn.on { background: var(--accent); color: var(--accent-text); border-color: var(--accent); font-weight: 700; }

/* ── scale list ── */
.scale-list {
  max-width: 720px; margin: 0 auto; padding: 1.25rem 1.5rem 0;
  display: flex; flex-direction: column; gap: 10px;
}
.scale-card {
  background: var(--surface); border: 0.5px solid var(--border);
  border-radius: 14px; overflow: hidden; transition: border-color 0.15s;
}
.scale-card:hover { border-color: var(--border2); }
.scale-card.open { border-color: var(--border2); }
.scale-summary {
  display: grid; grid-template-columns: 4px 1fr auto; gap: 0 14px;
  align-items: center; padding: 14px 16px 14px 0; width: 100%;
  border: 0; background: transparent; color: inherit; text-align: left;
  user-select: none; -webkit-user-select: none;
}
.scale-accent-bar { border-radius: 0 2px 2px 0; width: 4px; align-self: stretch; min-height: 48px; }
.scale-main { min-width: 0; }
.scale-title { font-size: 15px; font-weight: 600; color: var(--text); letter-spacing: -0.01em; }
.scale-notes { font-family: var(--font); font-size: 12px; color: var(--accent); margin-top: 3px; letter-spacing: 0.03em; }
.scale-mood { font-size: 13px; color: var(--muted); margin-top: 4px; }
.genre-row { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 8px; }
.pill {
  font-family: var(--font); font-size: 10px; padding: 2px 9px;
  border-radius: 99px; border: 0.5px solid; letter-spacing: 0.03em;
}
.chevron {
  color: var(--hint); font-size: 18px; transition: transform 0.2s;
  flex-shrink: 0; padding-right: 4px; font-weight: 400; line-height: 1;
}
.scale-card.open .chevron { transform: rotate(180deg); }

/* ── expanded detail ── */
.scale-detail { display: none; padding: 0 16px 16px 18px; border-top: 0.5px solid var(--border); }
.scale-card.open .scale-detail { display: block; }
.detail-section { margin-top: 14px; }
.detail-label {
  font-family: var(--font); font-size: 10px; letter-spacing: 0.1em;
  color: var(--hint); text-transform: uppercase; margin-bottom: 6px;
}
.prog-item { background: var(--surface2); border-radius: 8px; margin-bottom: 6px; overflow: hidden; }
.prog-row { display: flex; align-items: center; gap: 10px; width: 100%; border: 0; background: transparent; color: inherit; text-align: left; padding: 9px 12px; }
.prog-rowmain { flex: 1; min-width: 0; }
.prog-static { padding: 9px 12px 0; }
.prog-name { font-family: var(--font); font-size: 12px; color: var(--accent); display: block; }
.prog-chords { font-family: var(--font); font-size: 13px; color: var(--text); display: block; margin-top: 2px; }
.prog-row .chevron { font-size: 14px; flex-shrink: 0; padding-right: 0; }
.prog-row.open .chevron { transform: rotate(180deg); }
.prog-panel { display: none; flex-wrap: wrap; gap: 10px; padding: 2px 12px 10px; }
.prog-panel.open { display: flex; }
.prog-panel .chord-box { flex: 1 1 220px; }
.prog-foot { padding: 4px 12px 9px; }
.prog-mood { font-size: 11px; color: var(--muted); font-style: italic; }
.prog-ref { font-size: 11px; color: var(--accent); margin-top: 3px; line-height: 1.4; }
.chord-box { flex: 0 0 auto; background: var(--surface); border: 0.5px solid var(--border); border-radius: 8px; padding: 9px 11px; min-width: 0; }
.chord-box-deg { font-family: var(--font); font-size: 10px; color: var(--accent); }
.chord-box-name { font-family: var(--font); font-size: 14px; font-weight: 700; color: var(--text); margin: 1px 0 8px; }
.voicing-stage { min-width: 0; }
.voicing.hidden { display: none; }
.voicing-nav { display: flex; align-items: center; gap: 6px; margin-top: 8px; }
.voicing-nav.single { justify-content: center; }
.vc-prev, .vc-next { width: 44px; height: 34px; flex: 0 0 auto; border-radius: 6px; border: 0.5px solid var(--border2); background: var(--surface2); color: var(--text); font-size: 17px; line-height: 1; display: flex; align-items: center; justify-content: center; }
.vc-prev:hover, .vc-next:hover { border-color: var(--accent); }
.vc-label { flex: 1; text-align: center; font-family: var(--font); font-size: 11px; color: var(--muted); }
.allchords-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; width: 100%; border: 0; background: var(--surface2); color: inherit; padding: 11px 12px; border-radius: 8px; font-size: 13px; font-weight: 600; }
.allchords-head .chevron { padding-right: 0; }
.allchords.open .allchords-head .chevron { transform: rotate(180deg); }
.allchords-body { display: none; margin-top: 10px; }
.allchords.open .allchords-body { display: block; }
.interval-box {
  background: var(--surface2); border-radius: 8px; padding: 8px 12px;
  font-family: var(--font); font-size: 12px; color: var(--muted);
  display: flex; gap: 6px; flex-wrap: wrap; align-items: center;
}
.interval-step { background: rgba(127,127,127,0.14); border-radius: 4px; padding: 2px 7px; font-size: 11px; color: var(--text); }
.interval-legend { font-size: 10px; color: var(--hint); width: 100%; margin-top: 4px; }

/* relations */
.rel-note { background: var(--surface2); border-radius: 8px; padding: 8px 12px; font-size: 12px; color: var(--muted); margin-bottom: 6px; }
.rel-note b { color: var(--text); font-weight: 600; }
.rel-modes { display: flex; flex-wrap: wrap; gap: 5px; margin-bottom: 6px; }
.rel-mode {
  font-family: var(--font); font-size: 10px; padding: 3px 8px; border-radius: 99px;
  border: 0.5px solid var(--border2); color: var(--muted);
}
.rel-mode.on { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }

/* diatonic chords */
.degree-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 10px; }
.degree-card { background: var(--surface2); border-radius: 8px; padding: 10px; min-width: 0; }
.degree-name { font-family: var(--font); font-size: 11px; color: var(--accent); }
.degree-chord { font-family: var(--font); font-size: 14px; color: var(--text); margin-top: 2px; overflow-wrap: anywhere; }
.chord-notes { font-family: var(--font); font-size: 11px; color: var(--muted); margin-top: 4px; }

/* instrument blocks */
.inst-piano { margin: 8px 0 4px; }
.inst-card { background: rgba(0,0,0,0.16); border: 0.5px solid var(--border); border-radius: 8px; padding: 9px 12px 11px; margin-top: 8px; min-width: 0; }
html[data-theme="light"] .inst-card { background: rgba(0,0,0,0.04); }
.inst-title { font-family: var(--font); font-size: 10px; color: var(--hint); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 8px; }

/* keyboard */
.kbd { width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch; overscroll-behavior-x: contain; padding-bottom: 2px; }
.kbd-inner { position: relative; display: flex; height: 92px; min-width: 250px; }
.wkey, .bkey {
  display: flex; align-items: flex-end; justify-content: center;
  font-family: var(--font); font-weight: 700; box-sizing: border-box;
  -webkit-user-select: none; user-select: none; overflow: hidden;
}
.wkey {
  flex: 1 0 0; min-width: 0; height: 100%; background: var(--key-bg);
  border: 1px solid rgba(0,0,0,0.32); border-radius: 0 0 5px 5px;
  color: #15151a; font-size: 9px; padding-bottom: 6px; position: relative; z-index: 1;
}
.bkey {
  position: absolute; top: 0; height: 60%; background: var(--key-black);
  border: 1px solid #000; border-top: 0; border-radius: 0 0 4px 4px;
  color: #cfcdc7; font-size: 8px; padding-bottom: 5px; z-index: 2;
}
.wkey.on { box-shadow: inset 0 -14px 0 var(--accent); color: var(--accent-text); }
.wkey.root { background: var(--accent); color: var(--accent-text); box-shadow: none; }
.bkey.on { box-shadow: inset 0 -12px 0 var(--accent); color: var(--accent-text); }
.bkey.root { background: var(--accent); color: var(--accent-text); box-shadow: none; }
.wkey span, .bkey span { position: relative; pointer-events: none; }

/* chord chart (fretboard diagram) */
.cc { display: inline-block; padding: 0 12px; }
.cc-row { position: relative; height: 14px; }
.cc-marks { margin-bottom: 4px; }
.cc-labels { margin-top: 6px; }
.cc-mark, .cc-lab {
  position: absolute; transform: translateX(-50%); font-family: var(--font);
  font-size: 10px; line-height: 14px; white-space: nowrap;
}
.cc-mark { color: var(--text); }
.cc-mark.muted { color: var(--hint); }
.cc-lab { color: var(--accent); }
.cc-grid { position: relative; }
.cc-string { position: absolute; top: 0; bottom: 0; width: 1px; background: var(--border2); transform: translateX(-0.5px); }
.cc-fret { position: absolute; left: 0; right: 0; height: 1px; background: var(--border2); }
.cc-fret.nut { height: 3px; border-radius: 1px; background: var(--text); }
.cc-dot { position: absolute; width: 15px; height: 15px; border-radius: 50%; background: var(--accent); transform: translate(-50%, -50%); z-index: 1; }
.cc-dot.root { background: var(--bg); box-shadow: 0 0 0 2px var(--accent); }
.cc-pos { position: absolute; left: -4px; transform: translate(-100%, -50%); font-family: var(--font); font-size: 9px; color: var(--muted); }
.cc-empty { color: var(--hint); font-size: 11px; padding: 6px 0; }

/* scale on the neck */
.neck-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; overscroll-behavior-x: contain; padding-bottom: 4px; }
.neck { display: inline-block; }
.neck-row { display: flex; align-items: stretch; }
.neck-string { flex: 0 0 24px; width: 24px; font: 700 10px var(--font); color: var(--muted); display: flex; align-items: center; justify-content: center; }
.neck-cell {
  flex: 0 0 30px; width: 30px; height: 30px; position: relative;
  border-right: 1px solid var(--border); border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
}
.neck-cell.open { border-right: 3px solid var(--text); }
.neck-row:first-child .neck-cell { border-top: 1px solid var(--border); }
.neck-dot {
  width: 24px; height: 24px; border-radius: 50%; background: var(--surface);
  border: 1px solid var(--border2); color: var(--text);
  font: 700 9px var(--font); display: flex; align-items: center; justify-content: center;
}
.neck-dot.root { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }
.neck-nums .neck-cell { border: 0; height: 18px; color: var(--hint); font: 10px var(--font); }

/* alterations reference */
.altref { max-width: 720px; margin: 1.25rem auto 0; padding: 0 1.5rem; }
.altref-card { background: var(--surface); border: 0.5px solid var(--border); border-radius: 14px; overflow: hidden; }
.altref-head {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  width: 100%; border: 0; background: transparent; color: inherit;
  padding: 16px; text-align: left; font-size: 15px; font-weight: 600;
}
.altref-head .chevron { padding-right: 0; }
.altref-card.open .chevron { transform: rotate(180deg); }
.altref-body { display: none; padding: 0 16px 8px; }
.altref-card.open .altref-body { display: block; }
.alt-item { display: grid; grid-template-columns: auto 1fr; gap: 4px 12px; padding: 10px 0; border-top: 0.5px solid var(--border); }
.alt-sym { font-family: var(--font); font-size: 12px; font-weight: 700; color: var(--accent); align-self: center; min-width: 56px; }
.alt-name { font-size: 13px; color: var(--text); }
.alt-formula { font-family: var(--font); font-size: 12px; color: var(--text); grid-column: 2; }
.alt-how { font-size: 12px; color: var(--muted); grid-column: 2; }

.no-results { color: var(--muted); border: 0.5px solid var(--border); border-radius: 10px; padding: 18px; text-align: center; }

/* toast */
#toast {
  position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%) translateY(20px);
  background: var(--accent); color: var(--accent-text); font-size: 13px; font-weight: 600;
  padding: 10px 18px; border-radius: 99px; opacity: 0; pointer-events: none;
  transition: opacity 0.2s, transform 0.2s; z-index: 50;
}
#toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}
@media (max-width: 480px) {
  header { padding: 1.75rem 1rem 1.5rem; }
  .header-actions { top: 1.75rem; right: 1rem; }
  .seg-wrap { padding: 0.75rem 1rem 0.25rem; }
  .search-wrap { padding: 0.6rem 1rem 0.2rem; }
  .filter-wrap { padding: 0.6rem 1rem; }
  .scale-list { padding: 1rem 1rem 0; }
  .altref { padding: 0 1rem; }
}