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

/* ── Theme variables ───────────────────────────────────────────────────────── */
:root {
  --bg: #f5f0e8;
  --surface: #fffdf8;
  --surface-raised: #ede5d8;
  --surface-deep: #f0e8dc;
  --border: #cdb89a;
  --text: #2a1608;
  --text-dim: #7a5538;
  --text-muted: #a87f5a;
  --label: #987050;
  --accent: #8b3a0f;
  --accent-rgb: 139,58,15;
  --accent-border: #b05525;
  --success-bg: #2a5a3a;
  --error-bg: #5a1a1a;
  --hint-bg: #fdf5e0;
  --hint-border: #b08820;
  --hint-text: #907010;
  --acc-dim: #c4a882;
  --acc-dim-border: #d4bc9a;
  --acc-active-bg: #fdecd8;
  --acc-active-text: #8b3a0f;
  --interactive-hover: rgba(0,0,0,0.06);
  --check-disabled-bg: #e8ddd0;
  --check-disabled-text: #b09878;
  --reset-color: #a87f5a;
  --octave-hover-border: #b09070;
  --octave-hover-text: #2a1608;
}
html[data-theme="dark"] {
  --bg: #180d06;
  --surface: #231408;
  --surface-raised: #2e1c0c;
  --surface-deep: #140a04;
  --border: #3e2810;
  --text: #e0ccb0;
  --text-dim: #9a7850;
  --text-muted: #664830;
  --label: #664830;
  --accent: #a84818;
  --accent-rgb: 168,72,24;
  --accent-border: #c86830;
  --success-bg: #2a5a3a;
  --error-bg: #5a1a1a;
  --hint-bg: #221408;
  --hint-border: #6a4a10;
  --hint-text: #c09030;
  --acc-dim: #5a3820;
  --acc-dim-border: #3e2810;
  --acc-active-bg: #3a1c08;
  --acc-active-text: #d4a060;
  --interactive-hover: rgba(255,200,150,0.08);
  --check-disabled-bg: #2e1c0c;
  --check-disabled-text: #5a3820;
  --reset-color: #664830;
  --octave-hover-border: #664830;
  --octave-hover-text: #e0ccb0;
}
@media (prefers-color-scheme: dark) {
  html[data-theme="auto"] {
    --bg: #180d06;
    --surface: #231408;
    --surface-raised: #2e1c0c;
    --surface-deep: #140a04;
    --border: #3e2810;
    --text: #e0ccb0;
    --text-dim: #9a7850;
    --text-muted: #664830;
    --label: #664830;
    --accent: #a84818;
    --accent-border: #c86830;
    --success-bg: #2a5a3a;
    --error-bg: #5a1a1a;
    --hint-bg: #221408;
    --hint-border: #6a4a10;
    --hint-text: #c09030;
    --acc-dim: #5a3820;
    --acc-dim-border: #3e2810;
    --acc-active-bg: #3a1c08;
    --acc-active-text: #d4a060;
    --interactive-hover: rgba(255,200,150,0.08);
    --check-disabled-bg: #2e1c0c;
    --check-disabled-text: #5a3820;
    --reset-color: #664830;
    --octave-hover-border: #664830;
    --octave-hover-text: #e0ccb0;
  }
}

body { background: var(--bg); color: var(--text); font-family: system-ui, sans-serif; min-height: 100vh; }
#app { max-width: 640px; margin: 0 auto; padding: 10px 16px; display: flex; flex-direction: column; min-height: 100vh; min-height: 100dvh; }

/* ── Header ────────────────────────────────────────────────────────────────── */
header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; flex-wrap: wrap; gap: 8px; }
#mode-menu { position: relative; }
#mode-current {
  background: var(--accent); border: 1px solid var(--accent-border); color: #fff;
  padding: 5px 12px; border-radius: 4px; cursor: pointer; font-size: 12px;
}
#mode-dropdown {
  display: none; position: absolute; top: calc(100% + 4px); left: 0;
  background: var(--surface); border: 1px solid var(--border); border-radius: 4px;
  z-index: 100; min-width: 160px; overflow: hidden;
}
#mode-menu.open #mode-dropdown { display: block; }
#mode-dropdown button {
  display: block; width: 100%; text-align: left;
  background: none; border: none; border-bottom: 1px solid var(--border);
  color: var(--text-dim); padding: 8px 12px; cursor: pointer; font-size: 12px;
}
#mode-dropdown button:last-child { border-bottom: none; }
#mode-dropdown button:hover { background: var(--surface-raised); color: var(--text); }
#mode-dropdown button.active { color: var(--accent); font-weight: 600; }
#session-stats { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--text-dim); }
#stats-display {
  cursor: pointer; border-radius: 4px; padding: 3px 8px;
  border: 1px solid var(--border); background: var(--surface);
}
#stats-display:hover { background: var(--surface-raised); border-color: var(--text-muted); color: var(--text); }
#stats-modal-footer {
  margin-top: 16px; padding-top: 12px; border-top: 1px solid var(--border);
  display: flex; justify-content: flex-end;
}
#reset-session {
  background: none; border: 1px solid var(--border); color: var(--reset-color);
  padding: 4px 12px; border-radius: 4px; cursor: pointer; font-size: 12px;
}
#reset-session:hover { border-color: var(--text-muted); color: var(--text-dim); }

/* ── Main layout ───────────────────────────────────────────────────────────── */
main { display: flex; flex-direction: column; align-items: center; gap: 14px; flex: 1; }
.section-label { font-size: 10px; text-transform: uppercase; letter-spacing: 1px; color: var(--label); margin-bottom: 4px; text-align: center; }
#staff-section, #fingerboard-section { width: 100%; display: flex; flex-direction: column; align-items: center; }

/* ── Staff ─────────────────────────────────────────────────────────────────── */
#staff-row { display: flex; align-items: center; gap: 6px; }
#staff-container { touch-action: none; }
#staff-container svg text,
#fingerboard-container svg text { user-select: none; }
#staff-accidental { display: flex; flex-direction: column; gap: 4px; }
#keysig-menu { position: relative; }
#keysig-current {
  background: var(--surface); border: 1px solid var(--border); color: var(--text-dim);
  padding: 4px 6px; border-radius: 4px; cursor: pointer; font-size: 11px; white-space: nowrap;
}
#keysig-current:hover { background: var(--surface-raised); }
#keysig-current:disabled { opacity: 0.6; cursor: default; }
#keysig-current:disabled:hover { background: var(--surface); }
#keysig-dropdown {
  display: none; position: absolute; top: calc(100% + 4px); left: 0;
  background: var(--surface); border: 1px solid var(--border); border-radius: 4px;
  z-index: 100; min-width: max-content; overflow: hidden;
}
#keysig-menu.open #keysig-dropdown { display: block; }
#keysig-dropdown button {
  display: block; width: 100%; text-align: center;
  background: none; border: none; border-bottom: 1px solid var(--border);
  padding: 6px 8px; cursor: pointer; font-size: 12px; color: var(--text-dim);
}
#keysig-dropdown button:last-child { border-bottom: none; }
#keysig-dropdown button:hover { background: var(--interactive-hover); }
#keysig-dropdown button.active { color: var(--accent); font-weight: 600; }
.acc-btn {
  width: 26px; height: 26px; border-radius: 4px; border: 1px solid var(--acc-dim-border);
  background: var(--surface-deep); color: var(--acc-dim); font-size: 16px; font-family: serif;
  cursor: default; pointer-events: none; line-height: 1;
  display: flex; align-items: center; justify-content: center;
}
.acc-btn.active { background: var(--acc-active-bg); border-color: var(--accent-border); color: var(--acc-active-text); }
.acc-btn.enabled { cursor: pointer; pointer-events: all; }
.acc-btn.enabled:hover { border-color: var(--accent-border); }

/* ── Fingerboard ───────────────────────────────────────────────────────────── */
#fingerboard-row { display: grid; grid-template-columns: 1fr auto 1fr; align-items: start; width: 100%; }
#position-col { display: flex; flex-direction: column; align-items: center; gap: 4px; padding-top: 16px; }
#position-col .pos-label { font-size: 10px; text-transform: uppercase; letter-spacing: 1px; color: var(--label); }
#keysig-group { display: flex; flex-direction: column; align-items: center; gap: 4px; margin-bottom: 8px; }
#position-menu { position: relative; }
#position-current {
  background: var(--surface); border: 1px solid var(--border); color: var(--text-dim);
  padding: 4px 6px; border-radius: 4px; cursor: pointer; font-size: 11px; white-space: nowrap;
}
#position-current:hover { background: var(--surface-raised); }
#position-dropdown {
  display: none; position: absolute; top: calc(100% + 4px); left: 0;
  background: var(--surface); border: 1px solid var(--border); border-radius: 4px;
  z-index: 100; min-width: 52px; overflow: hidden;
}
#position-menu.open #position-dropdown { display: block; }
#position-dropdown button {
  display: block; width: 100%; text-align: center;
  background: none; border: none; border-bottom: 1px solid var(--border);
  padding: 6px 8px; cursor: pointer; font-size: 12px; color: var(--text-dim);
}
#position-dropdown button:last-child { border-bottom: none; }
#position-dropdown button:hover { background: var(--interactive-hover); }
#position-dropdown button.active { color: var(--accent); font-weight: 600; }

/* ── Controls ──────────────────────────────────────────────────────────────── */
#controls { width: 100%; display: flex; flex-direction: column; align-items: center; gap: 8px; }
#note-picker { display: grid; grid-template-columns: repeat(7, 1fr); gap: 4px; width: 100%; max-width: 380px; }
#note-picker button {
  background: var(--surface); border: 1px solid var(--border); color: var(--text-dim);
  padding: 6px 4px; border-radius: 4px; cursor: pointer; font-size: 13px;
  text-align: center; width: 100%;
}
#note-picker button.acc { background: var(--surface-deep); font-size: 12px; padding: 4px; }
#note-picker button.active { background: var(--accent); border-color: var(--accent-border); color: #fff; }
#note-picker button.acc.active { background: var(--accent); }
#note-picker button.keysig { border-color: var(--accent-border); color: var(--accent); }
#note-picker button:disabled { opacity: 0.3; cursor: default; }
#note-picker button.active:disabled { opacity: 1; }
#quiz-controls { display: flex; gap: 10px; }
#check-btn, #next-btn {
  padding: 8px 24px; border-radius: 4px; cursor: pointer; font-size: 14px; border: none;
}
#check-btn { background: var(--accent); color: #fff; }
#check-btn:disabled { background: var(--check-disabled-bg); color: var(--check-disabled-text); cursor: default; }
#next-btn { background: var(--success-bg); color: #fff; }
#feedback { font-size: 14px; min-height: 20px; text-align: center; }
.feedback-correct { color: #4caf50; }
.feedback-wrong { color: #f44336; }
#study-octave-control {
  display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--text-dim);
}
#study-octave-control button {
  background: var(--surface); border: 1px solid var(--border); color: var(--text-dim);
  width: 28px; height: 28px; border-radius: 4px; cursor: pointer; font-size: 16px; line-height: 1;
}
#study-octave-control button:hover:not(:disabled) { border-color: var(--octave-hover-border); color: var(--octave-hover-text); }
#study-octave-control button:disabled { opacity: 0.3; cursor: default; }

/* ── SVG interactive states ────────────────────────────────────────────────── */
.staff-step { cursor: pointer; }
.staff-step:hover { fill: var(--interactive-hover) !important; }
.fb-slot { cursor: pointer; }
.fb-slot:hover { fill: var(--interactive-hover) !important; }

/* ── Stats modal ────────────────────────────────────────────────────────────── */
#stats-modal { position: fixed; inset: 0; z-index: 200; }
#stats-modal-backdrop { position: absolute; inset: 0; background: rgba(0,0,0,0.4); }
#stats-modal-card {
  position: absolute; top: 16px; left: 50%; transform: translateX(-50%);
  background: var(--surface); border: 1px solid var(--border); border-radius: 8px;
  padding: 16px; width: min(420px, calc(100% - 32px));
  max-height: calc(100vh - 32px); overflow-y: auto;
}
#stats-modal-header {
  display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px;
}
#stats-modal-title { font-size: 14px; font-weight: 600; color: var(--text); }
#stats-modal-close {
  background: none; border: none; cursor: pointer; color: var(--text-dim);
  font-size: 14px; padding: 2px 6px; border-radius: 3px;
}
#stats-modal-close:hover { background: var(--surface-raised); color: var(--text); }
#stats-modal-content h3 {
  font-size: 10px; text-transform: uppercase; letter-spacing: 1px; color: var(--label);
  margin: 14px 0 6px;
}
#stats-modal-content h3:first-child { margin-top: 0; }
.stats-tbl { width: 100%; border-collapse: collapse; font-size: 12px; }
.stats-tbl th {
  color: var(--text-muted); font-weight: normal; text-align: left;
  padding: 3px 8px 4px 0; border-bottom: 1px solid var(--border);
}
.stats-tbl th:not(:first-child), .stats-tbl td:not(:first-child) { text-align: right; }
.stats-tbl td { color: var(--text-dim); padding: 5px 8px 5px 0; border-bottom: 1px solid var(--surface-raised); }
.stats-tbl tr:last-child td { border-bottom: none; }
.stats-empty { font-size: 12px; color: var(--text-muted); font-style: italic; }

.stats-key-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; margin-bottom: 10px; }
.stats-key-tile {
  border-radius: 5px; padding: 7px 4px; text-align: center; cursor: pointer;
  display: flex; flex-direction: column; gap: 2px; border: 1.5px solid transparent;
  transition: filter 0.1s;
}
.stats-key-tile--empty { border: 1.5px dashed var(--border); }
.stats-key-tile--light { color: var(--text); }
.stats-key-tile--dark  { color: #fff; }
.stats-key-tile--selected { box-shadow: 0 0 0 2px var(--accent); }
.stats-key-tile:hover { filter: brightness(1.08); }
.stats-key-name { font-size: 11px; font-weight: 600; }
.stats-key-sub  { font-size: 9px; }
.stats-key-tile--dark  .stats-key-sub { color: rgba(255,255,255,0.8); }
.stats-key-tile--light .stats-key-sub { color: var(--text-dim); }
.stats-key-tile--empty .stats-key-sub { color: var(--text-muted); }

#stats-key-detail {
  background: var(--surface-deep); border: 1px solid var(--border); border-radius: 6px;
  padding: 12px; margin-bottom: 14px;
}
.stats-key-detail-header {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: 10px; font-size: 12px; color: var(--text);
}
.stats-detail-section-label {
  font-size: 10px; text-transform: uppercase; letter-spacing: 1px; color: var(--label);
  margin: 10px 0 5px;
}
.stats-detail-row {
  display: flex; align-items: center; gap: 6px; margin-bottom: 5px;
  font-size: 12px; color: var(--text-dim);
}
.stats-detail-row span:first-child { min-width: 80px; }
.stats-mode-list { margin-bottom: 4px; }
.stats-mode-row {
  display: flex; align-items: center; gap: 6px; margin-bottom: 6px;
  font-size: 12px; color: var(--text-dim);
}
.stats-mode-row span:first-child { min-width: 80px; }
.stats-mode-score { min-width: 80px; text-align: right; font-size: 11px; color: var(--text-muted); flex-shrink: 0; }
.stats-bar-track { flex: 1; height: 5px; background: var(--surface-raised); border-radius: 3px; overflow: hidden; min-width: 40px; }
.stats-bar-fill  { height: 100%; background: var(--accent); opacity: 0.7; border-radius: 3px; }

/* ── Bottom bar ────────────────────────────────────────────────────────────── */
#bottom-bar {
  margin-top: auto; padding: 8px 0; border-top: 1px solid var(--border);
  display: flex; justify-content: space-between; align-items: center;
}
#theme-menu, #lang-menu { position: relative; display: inline-block; }
#theme-current, #lang-current {
  background: var(--surface); border: 1px solid var(--border); color: var(--text-dim);
  padding: 4px 12px; border-radius: 4px; cursor: pointer; font-size: 12px;
}
#theme-menu.open #theme-current,
#lang-menu.open #lang-current { border-color: var(--accent-border); color: var(--accent); }
#theme-dropdown, #lang-dropdown {
  display: none; position: absolute; bottom: calc(100% + 4px);
  background: var(--surface); border: 1px solid var(--border); border-radius: 4px;
  z-index: 100; min-width: 100px; overflow: hidden;
}
#theme-dropdown { left: 0; }
#lang-dropdown { right: 0; }
#theme-menu.open #theme-dropdown,
#lang-menu.open #lang-dropdown { display: block; }
#theme-dropdown button, #lang-dropdown button {
  display: block; width: 100%; text-align: left;
  background: none; border: none; border-bottom: 1px solid var(--border);
  color: var(--text-dim); padding: 8px 12px; cursor: pointer; font-size: 12px;
}
#theme-dropdown button:last-child, #lang-dropdown button:last-child { border-bottom: none; }
#theme-dropdown button:hover, #lang-dropdown button:hover { background: var(--surface-raised); color: var(--text); }
#theme-dropdown button.active, #lang-dropdown button.active { color: var(--accent); font-weight: 600; }

/* ── Tour ──────────────────────────────────────────────────────────────────── */
#tour-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  pointer-events: none;
  display: none;
}
#tour-overlay.active { display: block; pointer-events: all; background: rgba(0,0,0,0.55); }
#tour-overlay.active.has-highlight { background: transparent; }

.tour-highlight {
  position: relative !important;
  z-index: 1001 !important;
  box-shadow: 0 0 0 3px var(--text), 0 0 0 9999px rgba(0,0,0,0.55) !important;
  border-radius: 6px;
}

#tour-tooltip {
  position: fixed;
  z-index: 1002;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  max-width: 320px;
  width: max-content;
  box-shadow: 0 4px 16px rgba(0,0,0,0.25);
  display: none;
  pointer-events: all;
}
#tour-tooltip.active { display: block; }

#tour-tooltip-text {
  font-size: 0.92rem;
  line-height: 1.5;
  color: var(--text);
  margin-bottom: 12px;
}

#tour-tooltip-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

#tour-tooltip-step {
  font-size: 0.8rem;
  color: var(--text-muted);
  flex-shrink: 0;
}

#tour-tooltip-buttons {
  display: flex;
  gap: 6px;
}

#tour-tooltip-buttons button {
  font-size: 0.82rem;
  padding: 4px 10px;
  border-radius: 4px;
  border: 1px solid var(--border);
  background: var(--surface-raised);
  color: var(--text);
  cursor: pointer;
}

#tour-tooltip-buttons button:hover { background: var(--interactive-hover); }

#tour-btn-next, #tour-btn-finish {
  background: var(--accent) !important;
  color: var(--bg) !important;
  border-color: var(--accent-border) !important;
}

#tour-help-btn {
  font-size: 0.85rem;
  padding: 2px 8px;
  border-radius: 4px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  margin-left: 8px;
}
#tour-help-btn:hover { background: var(--interactive-hover); }