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

/* ─── Root & Palette ─── */
:root {
  --bg-deep: #0a0a0f;
  --bg-card: rgba(18, 18, 26, 0.85);
  --gold: #d4a853;
  --gold-glow: rgba(212, 168, 83, 0.35);
  --gold-dim: #a07d3a;
  --ivory: #f0ece4;
  --text: #e8e4dc;
  --text-dim: rgba(232, 228, 220, 0.45);
  --border: rgba(255, 255, 255, 0.06);
}

/* ─── Body ─── */
body {
  font-family: 'DM Sans', sans-serif;
  background: var(--bg-deep);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: var(--text);
  overflow: hidden;
}

/* Ambient background */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 40%, rgba(212, 168, 83, 0.06), transparent),
    radial-gradient(ellipse 50% 80% at 20% 80%, rgba(90, 60, 20, 0.08), transparent),
    radial-gradient(ellipse 50% 50% at 80% 20%, rgba(40, 30, 60, 0.1), transparent);
  pointer-events: none;
  z-index: 0;
}

/* ─── Page Transitions ─── */
.page {
  position: fixed;
  inset: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: opacity 0.45s ease, transform 0.45s ease;
}

.page.hidden {
  opacity: 0;
  transform: scale(0.97);
  pointer-events: none;
}

.page.visible {
  opacity: 1;
  transform: scale(1);
  pointer-events: auto;
}

/* ══════════════════════════════════
   START PAGE
   ══════════════════════════════════ */

.start-page {
  z-index: 10;
  animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.start-card {
  text-align: center;
  padding: 56px 48px 44px;
  border-radius: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  backdrop-filter: blur(40px);
  -webkit-backdrop-filter: blur(40px);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.04) inset,
    0 40px 80px -20px rgba(0, 0, 0, 0.6),
    0 0 120px -40px var(--gold-glow);
  max-width: 420px;
  width: 90vw;
}

/* Mini piano icon */
.piano-icon {
  display: inline-flex;
  gap: 2px;
  margin-bottom: 32px;
  padding: 8px 12px 6px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
}

.piano-icon .key {
  display: block;
  border-radius: 0 0 3px 3px;
}

.piano-icon .key.w {
  width: 12px;
  height: 32px;
  background: var(--ivory);
  opacity: 0.8;
}

.piano-icon .key.b {
  width: 9px;
  height: 20px;
  background: #1a1a24;
  border: 1px solid rgba(255, 255, 255, 0.08);
  margin: 0 -4px;
  position: relative;
  z-index: 1;
}

.title {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 500;
  font-size: 2.4rem;
  letter-spacing: -0.02em;
  color: var(--ivory);
  margin-bottom: 12px;
}

.subtitle {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text-dim);
  margin-bottom: 36px;
  font-weight: 400;
}

/* Start button */
.start-btn {
  display: block;
  width: 100%;
  padding: 16px 32px;
  font-family: 'DM Sans', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--bg-deep);
  background: linear-gradient(135deg, var(--gold) 0%, #e8c06a 100%);
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 4px 20px -4px var(--gold-glow);
}

.start-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 30px -4px var(--gold-glow);
}

.start-btn:active {
  transform: translateY(0);
  box-shadow: 0 2px 12px -2px var(--gold-glow);
}

/* Test audio button */
.test-btn {
  display: inline-block;
  margin-top: 16px;
  padding: 8px 20px;
  font-family: 'DM Sans', sans-serif;
  font-size: 0.82rem;
  font-weight: 400;
  color: var(--text-dim);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.test-btn:hover {
  color: var(--text);
  border-color: rgba(255, 255, 255, 0.12);
}

/* ══════════════════════════════════
   MODE SELECTION PAGE
   ══════════════════════════════════ */

.mode-page {
  z-index: 10;
}

.mode-card {
  text-align: center;
  padding: 48px 40px 40px;
  border-radius: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  backdrop-filter: blur(40px);
  -webkit-backdrop-filter: blur(40px);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.04) inset,
    0 40px 80px -20px rgba(0, 0, 0, 0.6),
    0 0 120px -40px var(--gold-glow);
  max-width: 480px;
  width: 90vw;
}

.mode-title {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 500;
  font-size: 1.6rem;
  letter-spacing: -0.01em;
  color: var(--ivory);
  margin-bottom: 28px;
}

.mode-options {
  display: flex;
  gap: 14px;
}

.mode-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 28px 16px 24px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 16px;
  cursor: pointer;
  color: var(--text);
  transition: border-color 0.25s ease, background 0.25s ease, transform 0.2s ease;
  font-family: 'DM Sans', sans-serif;
}

.mode-btn:hover {
  border-color: var(--gold);
  background: rgba(212, 168, 83, 0.04);
  transform: translateY(-2px);
}

.mode-btn:active {
  transform: translateY(0);
}

.mode-icon {
  font-size: 2rem;
  opacity: 0.7;
}

.mode-label {
  font-size: 1rem;
  font-weight: 600;
  color: var(--ivory);
}

.mode-desc {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-weight: 400;
}

/* ─── Song Picker ─── */

.song-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 20px;
}

.song-btn {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 16px 20px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 12px;
  cursor: pointer;
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  text-align: left;
  transition: border-color 0.25s ease, background 0.25s ease;
}

.song-btn:hover {
  border-color: var(--gold);
  background: rgba(212, 168, 83, 0.04);
}

.song-title {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--ivory);
}

.song-meta {
  font-size: 0.78rem;
  color: var(--text-dim);
  white-space: nowrap;
  margin-left: 12px;
}

.back-link {
  display: inline-block;
  padding: 8px 16px;
  font-family: 'DM Sans', sans-serif;
  font-size: 0.82rem;
  font-weight: 400;
  color: var(--text-dim);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: color 0.2s ease;
}

.back-link:hover {
  color: var(--text);
}

/* Hidden utility */
.hidden {
  display: none !important;
}

/* Override for page transitions (use opacity, not display:none) */
.page.hidden {
  display: flex !important;
  opacity: 0;
  transform: scale(0.97);
  pointer-events: none;
}

/* ══════════════════════════════════
   PLAY PAGE
   ══════════════════════════════════ */

.play-page {
  z-index: 5;
  flex-direction: column;
}

.back-btn {
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 20;
  padding: 8px 16px;
  font-family: 'DM Sans', sans-serif;
  font-size: 0.82rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.5);
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 8px;
  cursor: pointer;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: color 0.2s ease, background 0.2s ease;
}

.back-btn:hover {
  color: rgba(255, 255, 255, 0.8);
  background: rgba(0, 0, 0, 0.5);
}

.video-wrap {
  position: relative;
  border-radius: 16px;
  overflow: hidden;
  box-shadow:
    0 20px 60px -15px rgba(0, 0, 0, 0.7),
    0 0 0 1px var(--border);
  max-width: 95vw;
  max-height: 80vh;
}

#video {
  display: block;
  transform: scaleX(-1);
  width: 100%;
  max-width: 960px;
}

#canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

/* Status text */
#status {
  margin-top: 16px;
  font-size: 0.85rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  transition: color 0.3s ease;
}

.status-hint {
  color: var(--text-dim);
}

.status-active {
  color: var(--gold-dim);
}

.status-error {
  color: #c45;
}