@font-face {
  font-family: "Bravura";
  src: url("https://cdn.jsdelivr.net/npm/@vexflow-fonts/bravura/bravura.woff2") format("woff2");
  font-display: swap;
}

@font-face {
  font-family: "Academico";
  src: url("https://cdn.jsdelivr.net/npm/@vexflow-fonts/academico/academico.woff2") format("woff2");
  font-display: swap;
}

:root {
  --bg: #1a1a2e;
  --bg-alt: #14152b;
  --surface: #16213e;
  --surface-strong: #22345f;
  --surface-soft: rgba(255, 255, 255, 0.04);
  --text: #e0e0e0;
  --muted: #b8bfd4;
  --staff: #faf7f1;
  --accent: #4ecca3;
  --accent-strong: #36b58b;
  --danger: #e94560;
  --danger-strong: #ff6b81;
  --shadow: 0 24px 70px rgba(4, 8, 20, 0.4);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 999px;
  --button-size: 84px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  background:
    radial-gradient(circle at top, rgba(78, 204, 163, 0.16), transparent 30%),
    radial-gradient(circle at bottom right, rgba(233, 69, 96, 0.22), transparent 25%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-alt) 100%);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button,
input,
textarea,
select {
  font: inherit;
}

.app-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 32px 0 40px;
}

/* ── Shared top nav ───────────────────────────────────────── */
.app-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.app-nav-brand {
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--text);
  font-size: 0.95rem;
}

.app-nav-links {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  padding: 5px;
}

.app-nav-link {
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.86rem;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: background 140ms ease, color 140ms ease;
}

.app-nav-link:hover,
.app-nav-link:focus-visible {
  color: var(--text);
  background: rgba(255, 255, 255, 0.06);
  outline: none;
}

.app-nav-link.is-active {
  color: #101425;
  background: linear-gradient(180deg, var(--accent) 0%, var(--accent-strong) 100%);
}

@media (max-width: 760px) {
  .app-nav {
    flex-direction: column;
    align-items: stretch;
  }

  .app-nav-links {
    justify-content: center;
  }
}

.topbar {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: flex-start;
  margin-bottom: 28px;
}

.branding h1,
.answers-header h2,
.card-toolbar h2,
.reference-copy h3 {
  margin: 0;
}

.eyebrow,
.card-kicker,
.subtitle,
.keyboard-shortcut,
.reference-tip,
.score-label,
.staff-prompt {
  color: var(--muted);
}

.eyebrow,
.card-kicker {
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.72rem;
  margin: 0 0 8px;
}

.subtitle {
  margin: 10px 0 0;
  max-width: 44ch;
  line-height: 1.6;
}

.scoreboard {
  display: grid;
  grid-template-columns: repeat(2, minmax(110px, 1fr));
  gap: 12px;
  min-width: min(100%, 300px);
}

.score-item,
.answer-panel,
.quiz-card {
  background: rgba(22, 33, 62, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.score-item {
  border-radius: var(--radius-md);
  padding: 14px 16px;
}

.score-item strong {
  display: block;
  font-size: 1.2rem;
  margin-top: 6px;
}

.main-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(310px, 0.9fr);
  gap: 24px;
  align-items: start;
}

.quiz-card,
.answer-panel {
  border-radius: var(--radius-lg);
  padding: 24px;
}

.card-toolbar,
.answers-header,
.staff-status-row,
.feedback-row,
.reference-copy {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
}

.toolbar-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.toggle-button {
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: var(--surface-soft);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 12px 18px;
  cursor: pointer;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
}

.toggle-button:hover,
.toggle-button:focus-visible {
  transform: translateY(-1px);
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.28);
  outline: none;
}

.toggle-button.is-on {
  background: rgba(78, 204, 163, 0.14);
  border-color: rgba(78, 204, 163, 0.38);
}

/* ── Zoom control ─────────────────────────────────────────── */
.zoom-control {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
}

.zoom-label {
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-right: 4px;
}

.zoom-btn {
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: transparent;
  color: var(--muted);
  border-radius: 10px;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  transition: background 140ms ease, color 140ms ease, border-color 140ms ease, transform 120ms ease;
}

.zoom-btn:hover,
.zoom-btn:focus-visible {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
  outline: none;
}

.zoom-btn.is-active {
  background: rgba(78, 204, 163, 0.18);
  border-color: rgba(78, 204, 163, 0.5);
  color: #cffff0;
}

.staff-card {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(255, 255, 255, 0.02));
  border-radius: calc(var(--radius-lg) - 6px);
  padding: 18px;
  margin-top: 22px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.quiz-card.is-correct .staff-card {
  border-color: rgba(78, 204, 163, 0.5);
  box-shadow: 0 0 0 1px rgba(78, 204, 163, 0.22), 0 20px 40px rgba(78, 204, 163, 0.1);
}

.quiz-card.is-wrong .staff-card {
  border-color: rgba(233, 69, 96, 0.5);
  box-shadow: 0 0 0 1px rgba(233, 69, 96, 0.18), 0 20px 40px rgba(233, 69, 96, 0.1);
}

.feedback-badge {
  min-width: 70px;
  text-align: center;
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--muted);
  transition: background 180ms ease, color 180ms ease, transform 180ms ease;
}

.feedback-badge.is-correct {
  background: rgba(78, 204, 163, 0.18);
  color: #cffff0;
}

.feedback-badge.is-wrong {
  background: rgba(233, 69, 96, 0.18);
  color: #ffd6dc;
}

.notation-stage {
  width: 100%;
  background: linear-gradient(180deg, #fffdf9 0%, var(--staff) 100%);
  border-radius: 22px;
  margin-top: 12px;
  padding: 12px 0 16px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  overflow: auto;
}

.notation-stage svg {
  display: block;
}

.reference-notation svg {
  max-width: 100%;
  height: auto;
}

.loading-copy {
  color: #49516a;
}

.hint-text,
.feedback-text {
  margin: 14px 0 0;
}

.hint-text {
  color: #29314b;
  font-weight: 700;
}

.is-hidden {
  display: none !important;
}

.feedback-row {
  margin-top: 8px;
  align-items: flex-end;
}

.feedback-text {
  min-height: 24px;
  font-weight: 600;
}

.quiz-card.is-correct .feedback-text {
  color: #9df1d5;
}

.quiz-card.is-wrong .feedback-text {
  color: #ffb7c2;
}

.streak-meter {
  min-width: 150px;
}

.streak-meter-track {
  height: 11px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 8px;
}

.streak-meter-fill {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent) 0%, #7af5cd 100%);
  transition: width 220ms ease;
}

.streak-meter-label {
  font-size: 0.9rem;
  color: var(--muted);
}

.reference-panel {
  margin-top: 18px;
  padding: 18px;
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.reference-copy {
  align-items: flex-start;
  flex-wrap: wrap;
}

.reference-copy p,
.reference-copy h3 {
  margin: 0;
}

.reference-notation {
  margin-top: 14px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(250, 247, 241, 0.96));
  border-radius: 18px;
  padding: 12px;
  overflow: hidden;
}

.reference-label-groups {
  margin-top: 12px;
  display: grid;
  gap: 8px;
}

.reference-label-row {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 8px;
}

.reference-label-row span {
  text-align: center;
  padding: 8px 6px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.05);
  color: var(--muted);
  font-size: 0.9rem;
}

.answer-buttons {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(var(--button-size), 100%), 1fr));
  gap: 14px;
  margin-top: 22px;
}

.note-button {
  min-height: var(--button-size);
  border: none;
  border-radius: 24px;
  background: linear-gradient(180deg, #243a6f 0%, #1c2d55 100%);
  color: white;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.16), 0 14px 30px rgba(0, 0, 0, 0.2);
  transition: transform 140ms ease, box-shadow 140ms ease, background 140ms ease, opacity 140ms ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.note-button:hover,
.note-button:focus-visible {
  transform: translateY(-2px);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.18), 0 16px 34px rgba(0, 0, 0, 0.25);
  outline: none;
}

.note-button:disabled {
  cursor: not-allowed;
  opacity: 0.88;
}

.note-button.is-correct {
  background: linear-gradient(180deg, var(--accent) 0%, var(--accent-strong) 100%);
}

.note-button.is-wrong {
  background: linear-gradient(180deg, var(--danger-strong) 0%, var(--danger) 100%);
}

.note-letter {
  font-size: 1.5rem;
  font-weight: 800;
}

.note-shortcut {
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.72);
}

.keyboard-shortcut {
  margin: 0;
  text-align: right;
}

@media (max-width: 980px) {
  .main-layout {
    grid-template-columns: 1fr;
  }

  .scoreboard {
    min-width: 0;
  }
}

@media (max-width: 760px) {
  .app-shell {
    width: min(100% - 20px, 1180px);
    padding-top: 20px;
  }

  .topbar,
  .card-toolbar,
  .answers-header,
  .feedback-row,
  .staff-status-row {
    flex-direction: column;
    align-items: stretch;
  }

  .scoreboard {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    width: 100%;
  }

  .toolbar-actions {
    width: 100%;
  }

  .zoom-control {
    width: 100%;
    justify-content: center;
  }

  .toggle-button {
    flex: 1 1 auto;
  }

  .notation-stage {
    min-height: 210px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
}