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

:root {
  --bg: #0a0a0a;
  --surface: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.1);
  --text: #e8e8e8;
  --text-dim: #888;
  --accent: #fff;
  --correct: #4ade80;
  --close: #fbbf24;
  --wrong: #f87171;
  --radius: 8px;
  --transition: 0.3s ease;
}

html, body {
  height: 100%;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
}

/* ── Backdrop ────────────────────────────────────── */
#backdrop {
  position: fixed;
  inset: -40px;
  z-index: 0;
  background-size: cover;
  background-position: center;
  filter: blur(50px) brightness(0.35) saturate(1.3);
  transition: background-image 0.8s ease, filter 0.6s ease;
  transform: scale(1.15);
}

#backdrop.revealed {
  filter: blur(20px) brightness(0.45) saturate(1.3);
}

/* ── Screens ─────────────────────────────────────── */
.screen {
  position: fixed;
  inset: 0;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
  overflow-y: auto;
}

.screen.active {
  opacity: 1;
  pointer-events: auto;
}

.container {
  width: 100%;
  max-width: 520px;
  padding: 2rem 1.5rem;
  text-align: center;
}

/* ── Start Screen ────────────────────────────────── */
#screen-start h1 {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0.75rem;
}

.subtitle {
  font-size: 1.05rem;
  color: var(--text-dim);
  margin-bottom: 0.4rem;
}

.instructions {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 2rem;
}

/* ── Buttons ─────────────────────────────────────── */
.btn-primary {
  display: inline-block;
  padding: 0.85rem 2.5rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--bg);
  background: var(--accent);
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: opacity var(--transition), transform var(--transition);
  width: 100%;
  max-width: 280px;
}

.btn-primary:hover {
  opacity: 0.85;
  transform: translateY(-1px);
}

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

.btn-secondary {
  display: inline-block;
  padding: 0.85rem 2.5rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
  width: 100%;
  max-width: 280px;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-1px);
}

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

.btn-text-link {
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 0.8rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: color var(--transition);
  padding: 0 0.5rem;
}

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

.mode-selection {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  align-items: center;
  width: 100%;
}

.meta-label {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-top: 1.5rem;
  margin-bottom: 0.6rem;
}

.difficulty-selection {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 1.75rem;
  width: 100%;
  max-width: 320px;
  margin-left: auto;
  margin-right: auto;
}

.btn-diff {
  flex: 1;
  padding: 0.55rem 0.25rem;
  font-size: 0.85rem;
  font-weight: 600;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-dim);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.btn-diff:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text);
}

.btn-diff.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg);
}

.btn-icon {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition);
}

.btn-icon:hover {
  background: rgba(255, 255, 255, 0.12);
}

.btn-icon-small {
  background: none;
  border: none;
  color: var(--text-dim);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition), color var(--transition);
}

.btn-icon-small:hover {
  background: var(--surface);
  color: var(--text);
}

.btn-icon-small .icon {
  width: 18px;
  height: 18px;
}

.icon {
  width: 18px;
  height: 18px;
  display: block;
}

/* ── Game Header ─────────────────────────────────── */
.game-header {
  position: relative;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

#round-counter {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

.meta {
  font-size: 0.8rem;
  color: var(--text-dim);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ── Track Info ──────────────────────────────────── */
#track-info {
  margin-bottom: 1.5rem;
}

.track-artists {
  font-size: 0.9rem;
  color: var(--text-dim);
  margin-bottom: 0.35rem;
}

.track-title {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

/* ── Audio Controls ──────────────────────────────── */
#audio-controls {
  margin-bottom: 1.75rem;
}

#audio-progress-bar {
  width: 100%;
  height: 4px;
  background: var(--surface);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 0.75rem;
  cursor: pointer;
}

#audio-progress-fill {
  height: 100%;
  width: 0%;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.15s linear;
}

.audio-buttons {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
}

/* ── Year Grid ───────────────────────────────────── */
#year-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-bottom: 1.5rem;
}

#year-grid button {
  min-width: 70px;
  flex: 0 1 calc(25% - 6px);
  max-width: 100px;
}

#year-grid button {
  padding: 0.6rem 0;
  font-size: 0.9rem;
  font-weight: 600;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition), color var(--transition), transform 0.15s ease;
}

#year-grid button:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-1px);
}

#year-grid button:disabled {
  cursor: default;
  opacity: 0.4;
}

#year-grid button.correct {
  background: var(--correct);
  border-color: var(--correct);
  color: var(--bg);
  opacity: 1;
}

#year-grid button.wrong {
  background: var(--wrong);
  border-color: var(--wrong);
  color: var(--bg);
  opacity: 1;
}

#year-grid button.close {
  background: var(--close);
  border-color: var(--close);
  color: var(--bg);
  opacity: 1;
}

/* ── Feedback ────────────────────────────────────── */
#feedback {
  margin-top: 1rem;
}

#feedback-text {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

#feedback-score {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 1.25rem;
}

.hidden {
  display: none !important;
}

/* ── Results Screen ──────────────────────────────── */
.results-header {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  margin-bottom: 0.5rem;
  width: 100%;
}

.results-header .btn-icon-small {
  position: absolute;
  left: 0;
}

.results-title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.results-actions {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  align-items: center;
  width: 100%;
}

.final-score {
  font-size: 2.8rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  letter-spacing: -0.04em;
}

#results-list {
  text-align: left;
  margin-bottom: 2rem;
  max-height: 45vh;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,0.15) transparent;
}

.result-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 0.75rem;
  border-bottom: 1px solid var(--border);
}

.result-item:last-child {
  border-bottom: none;
}

.result-album {
  width: 40px;
  height: 40px;
  border-radius: 4px;
  object-fit: cover;
  flex-shrink: 0;
}

.result-details {
  flex: 1;
  min-width: 0;
}

.result-name {
  font-size: 0.85rem;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.result-artist {
  font-size: 0.75rem;
  color: var(--text-dim);
}

.result-badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  flex-shrink: 0;
}

.result-badge.exact {
  background: var(--correct);
  color: var(--bg);
}

.result-badge.near {
  background: var(--close);
  color: var(--bg);
}

.result-badge.far {
  background: var(--wrong);
  color: var(--bg);
}

/* ── Responsive ──────────────────────────────────── */
@media (max-width: 480px) {
  #screen-start h1 {
    font-size: 1.6rem;
  }

  .track-title {
    font-size: 1.3rem;
  }

  #year-grid {
    gap: 6px;
  }

  #year-grid button {
    min-width: 60px;
    padding: 0.5rem 0;
    font-size: 0.8rem;
  }

  .container {
    padding: 1.5rem 1rem;
  }
}

/* ── Scrollbar (Webkit) ──────────────────────────── */
#results-list::-webkit-scrollbar {
  width: 4px;
}

#results-list::-webkit-scrollbar-track {
  background: transparent;
}

#results-list::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 2px;
}

/* ── Mode Divider ────────────────────────────────── */
.mode-divider {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin: 1.5rem 0;
  color: var(--text-dim);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.mode-divider::before,
.mode-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.btn-song-mode {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: #fff;
  border: none;
}

.btn-song-mode:hover {
  opacity: 0.9;
}

.song-mode-desc {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 0.4rem;
}

/* ── Song Guess Game Screen ─────────────────────── */
#screen-song-game .container {
  max-width: 560px;
}

.song-progress-bar {
  width: 100%;
  height: 4px;
  background: var(--surface);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 0.75rem;
  cursor: pointer;
}

.song-progress-fill {
  height: 100%;
  width: 0%;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.15s linear;
}

/* ── Song Search ─────────────────────────────────── */
#song-search-area {
  position: relative;
  margin-bottom: 1.5rem;
}

.search-input-wrap {
  position: relative;
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  color: var(--text-dim);
  pointer-events: none;
}

#song-search-input {
  width: 100%;
  padding: 0.85rem 1rem 0.85rem 2.75rem;
  font-size: 1rem;
  font-family: inherit;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  outline: none;
  transition: border-color var(--transition), background var(--transition);
}

#song-search-input::placeholder {
  color: var(--text-dim);
}

#song-search-input:focus {
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.08);
}

#song-search-input:disabled {
  opacity: 0.4;
  cursor: default;
}

#song-search-results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  max-height: 320px;
  overflow-y: auto;
  background: rgba(20, 20, 20, 0.97);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius) var(--radius);
  z-index: 10;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,0.15) transparent;
}

#song-search-results::-webkit-scrollbar {
  width: 4px;
}

#song-search-results::-webkit-scrollbar-track {
  background: transparent;
}

#song-search-results::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 2px;
}

.search-result-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0.85rem;
  cursor: pointer;
  transition: background var(--transition);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.search-result-item:last-child {
  border-bottom: none;
}

.search-result-item:hover {
  background: rgba(255, 255, 255, 0.08);
}

.search-result-album {
  width: 36px;
  height: 36px;
  border-radius: 4px;
  object-fit: cover;
  flex-shrink: 0;
}

.search-result-info {
  flex: 1;
  min-width: 0;
  text-align: left;
}

.search-result-name {
  font-size: 0.85rem;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.search-result-artist {
  font-size: 0.75rem;
  color: var(--text-dim);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.search-no-results {
  padding: 1rem;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.85rem;
}

/* ── Song Feedback ───────────────────────────────── */
#song-feedback {
  margin-top: 1rem;
}

.song-reveal-track {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}

.song-reveal-artist {
  font-size: 0.95rem;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
}

#song-feedback-text {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

#song-feedback-score {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 1.25rem;
}

/* ── Song mode audio controls ────────────────────── */
#song-audio-controls {
  margin-bottom: 1.75rem;
}

/* ── Responsive additions ────────────────────────── */
@media (max-width: 480px) {
  #song-search-results {
    max-height: 250px;
  }

  .song-reveal-track {
    font-size: 1.15rem;
  }
}