:root {
    --bg: #0a0a0f;
    --surface: #12121a;
    --surface2: #1a1a28;
    --text: #c8c8d4;
    --text-dim: #6a6a7a;
    --accent: #e04090;
    --accent2: #40c0e0;
    --accent3: #e0a040;
    --accent4: #60e060;
    --glow-pink: rgba(224, 64, 144, 0.4);
    --glow-blue: rgba(64, 192, 224, 0.3);
    --glow-amber: rgba(224, 160, 64, 0.3);
    --glow-green: rgba(96, 224, 96, 0.3);
  }

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

  body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    overflow-x: hidden;
  }

  /* Animated background */
  .bg-ambient {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    pointer-events: none; z-index: 0;
    background:
      radial-gradient(ellipse at 30% 20%, rgba(224,64,144,0.06) 0%, transparent 60%),
      radial-gradient(ellipse at 70% 60%, rgba(64,192,224,0.05) 0%, transparent 60%),
      radial-gradient(ellipse at 50% 80%, rgba(96,224,96,0.04) 0%, transparent 50%);
  }

  /* Main layout */
  .container {
    position: relative; z-index: 1;
    width: 100%; max-width: 700px;
    padding: 2rem 1.5rem;
    display: flex; flex-direction: column; align-items: center;
    gap: 2rem;
  }

  /* Header */
  header {
    text-align: center;
  }
  header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), var(--accent2), var(--accent3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
    text-shadow: none;
    filter: drop-shadow(0 0 20px var(--glow-pink));
  }
  header p {
    color: var(--text-dim);
    font-size: 0.95rem;
    margin-top: 0.3rem;
    letter-spacing: 0.05em;
  }

  /* Orb visualizer */
  .orb-container {
    position: relative;
    width: 180px; height: 180px;
    display: flex; align-items: center; justify-content: center;
  }
  .orb {
    width: 120px; height: 120px;
    border-radius: 50%;
    background: radial-gradient(circle at 35% 35%, var(--accent2), var(--accent) 60%, transparent 100%);
    box-shadow:
      0 0 60px var(--glow-pink),
      0 0 120px var(--glow-blue),
      inset 0 0 40px rgba(255,255,255,0.05);
    transition: transform 0.1s ease-out, box-shadow 0.3s ease;
    animation: orb-breathe 4s ease-in-out infinite;
  }
  .orb.playing {
    animation-duration: 2s;
    box-shadow:
      0 0 80px var(--glow-pink),
      0 0 160px var(--glow-blue),
      inset 0 0 60px rgba(255,255,255,0.08);
  }
  .orb-rings { position: absolute; }
  .orb-ring {
    position: absolute;
    border-radius: 50%;
    border: 1px solid rgba(255,255,255,0.08);
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    transition: all 0.3s ease;
  }

  @keyframes orb-breathe {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.12); }
  }

  /* Play button */
  .play-btn {
    width: 80px; height: 80px;
    border-radius: 50%;
    border: 2px solid rgba(255,255,255,0.15);
    background: var(--surface2);
    color: white;
    font-size: 2rem;
    cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    transition: all 0.3s ease;
    box-shadow: 0 0 30px rgba(0,0,0,0.3);
    position: absolute;
    z-index: 2;
  }
  .play-btn:hover {
    border-color: var(--accent);
    box-shadow: 0 0 40px var(--glow-pink);
  }
  .play-btn.playing {
    border-color: var(--accent2);
    box-shadow: 0 0 40px var(--glow-blue);
  }

  /* Controls panel */
  .controls {
    width: 100%;
    background: var(--surface);
    border-radius: 20px;
    padding: 2rem;
    border: 1px solid rgba(255,255,255,0.06);
    display: flex; flex-direction: column;
    gap: 1.5rem;
  }

  .control-group {
    display: flex; flex-direction: column;
    gap: 0.5rem;
  }

  .control-label {
    display: flex; justify-content: space-between;
    align-items: center;
  }
  .control-label span:first-child {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
  }
  .control-val {
    font-size: 0.85rem;
    color: var(--text-dim);
    font-variant-numeric: tabular-nums;
    font-family: 'SF Mono', 'JetBrains Mono', monospace;
    min-width: 32px; text-align: right;
  }

  /* Custom slider */
  input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--surface2);
    outline: none;
    cursor: pointer;
  }
  input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px; height: 24px;
    border-radius: 50%;
    background: var(--surface);
    border: 2px solid var(--accent);
    cursor: pointer;
    box-shadow: 0 0 12px var(--glow-pink);
    transition: all 0.2s ease;
  }
  input[type="range"]::-webkit-slider-thumb:hover {
    box-shadow: 0 0 24px var(--glow-pink);
  }
  /* Firefox */
  input[type="range"]::-moz-range-track {
    height: 8px;
    border-radius: 4px;
    background: var(--surface2);
  }
  input[type="range"]::-moz-range-thumb {
    width: 20px; height: 20px;
    border-radius: 50%;
    background: var(--surface);
    border: 2px solid var(--accent);
    cursor: pointer;
    box-shadow: 0 0 12px var(--glow-pink);
  }

  /* Color-coded tracks */
  #tempo::-webkit-slider-thumb { border-color: var(--accent2); box-shadow: 0 0 12px var(--glow-blue); }
  #warmth::-webkit-slider-thumb { border-color: var(--accent3); box-shadow: 0 0 12px var(--glow-amber); }
  #bassBoost::-webkit-slider-thumb { border-color: #ff6b6b; box-shadow: 0 0 12px rgba(255,107,107,0.4); }
  #beats::-webkit-slider-thumb { border-color: var(--accent); box-shadow: 0 0 12px var(--glow-pink); }
  #melody::-webkit-slider-thumb { border-color: var(--accent4); box-shadow: 0 0 12px var(--glow-green); }
  #variety::-webkit-slider-thumb { border-color: #b070f0; box-shadow: 0 0 12px rgba(176,112,240,0.4); }
  #mixItUp::-webkit-slider-thumb { border-color: #50d0d0; box-shadow: 0 0 12px rgba(80,208,208,0.4); }
  #shiftNow:hover { border-color: #b070f0; box-shadow: 0 0 12px rgba(176,112,240,0.4); }

  /* Genre selector — 3x3 grid */
  .genres-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
    width: 100%;
    max-width: 500px;
  }
  .genre-btn {
    background: var(--surface);
    color: var(--text);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 12px;
    padding: 0.65rem 0.4rem;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s ease;
    letter-spacing: 0.03em;
    text-align: center;
    white-space: nowrap;
  }
  .genre-btn:hover {
    border-color: var(--accent2);
    box-shadow: 0 0 16px var(--glow-blue);
  }
  .genre-btn.active {
    background: linear-gradient(135deg, rgba(224,64,144,0.25), rgba(64,192,224,0.25));
    border-color: var(--accent);
    box-shadow: 0 0 20px var(--glow-pink);
    color: #fff;
  }

  /* Tick marks */
  .tick-marks {
    display: flex; justify-content: space-between;
    padding: 0 4px;
    font-size: 0.65rem;
    color: var(--text-dim);
    margin-top: -0.3rem;
  }

  /* Variant whose labels are placed at exact track positions (see sleep timer).
     Offsets in the inline left: calc() account for the 24px thumb inset. */
  .tick-marks-pos {
    display: block;
    position: relative;
    height: 1em;
    padding: 0;
    margin-top: 0.35rem; /* clear the 24px thumb, which now sits over a label */
  }
  .tick-marks-pos span {
    position: absolute;
    transform: translateX(-50%);
    white-space: nowrap;
  }

  .sleep-section {
    width: 100%;
    max-width: 500px;
    background: var(--surface);
    border: 1px solid rgba(255,255,255,0.06);
    border-radius: 16px;
    padding: 1.5rem;
    margin-top: 1rem;
  }
  
  .sleep-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    font-weight: 500;
  }
  
  .sleep-countdown {
    text-align: center;
    margin-top: 1rem;
    font-size: 0.9rem;
    color: var(--accent);
    min-height: 1.2em;
  }
  
  .sleep-options {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(255,255,255,0.08);
  }

  /* Footer */
  footer {
    color: var(--text-dim);
    font-size: 0.75rem;
    text-align: center;
    opacity: 0.6;
  }

  /* Sleep timer and TTS controls */
  .sleep-timer, .volume-controls, .tts-phrase {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
    max-width: 480px;
    padding: 0.75rem 1rem;
    background: var(--surface);
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.08);
  }
  
  .sleep-timer label, .volume-controls label, .tts-phrase label {
    color: var(--text-dim);
    font-size: 0.85rem;
    font-weight: 500;
    min-width: 90px;
  }
  
  .sleep-timer select, .volume-controls select, .tts-phrase input {
    flex: 1;
    background: var(--surface2);
    color: var(--text);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 6px;
    padding: 0.4rem 0.6rem;
    font-size: 0.9rem;
    font-family: inherit;
  }
  
  .sleep-timer select:focus, .volume-controls select:focus, .tts-phrase input:focus {
    outline: none;
    border-color: var(--accent2);
    box-shadow: 0 0 8px var(--glow-blue);
  }
  
  #sleepCountdown {
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 600;
  }
  
  .tts-phrase input::placeholder {
    color: var(--text-dim);
    opacity: 0.6;
  }

  /* Visualizer */
  .viz-container {
    position: relative;
    width: 100%;
    max-width: 600px;
    height: 200px;
    margin: 1rem 0;
    border-radius: 16px;
    overflow: hidden;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
  }

  /* MilkDrop (Butterchurn) WebGL canvas */
  #mdCanvas {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    display: block;
    transition: opacity 3s ease;
  }
  /* fades to black after playback stops (pause or sleep timer) */
  #mdCanvas.md-asleep {
    opacity: 0;
  }

  .viz-controls {
    position: absolute;
    bottom: 1rem;
    right: 1rem;
    display: flex;
    gap: 0.5rem;
    transition: opacity 0.4s ease;
  }

  .viz-mode-btn, .viz-fs-btn {
    background: rgba(18, 18, 26, 0.85);
    color: var(--text);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 8px;
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s ease;
    backdrop-filter: blur(6px);
  }

  .viz-fs-btn {
    padding: 0.5rem 0.75rem;
    font-size: 1rem;
  }

  .viz-mode-btn:hover, .viz-fs-btn:hover {
    background: rgba(18, 18, 26, 0.95);
    border-color: var(--accent2);
    box-shadow: 0 0 16px var(--glow-blue);
  }

  .viz-mode-btn:active, .viz-fs-btn:active {
    transform: scale(0.96);
  }

  /* Fullscreen mode */
  .viz-container:fullscreen {
    display: block;
    width: 100vw;
    height: 100vh;
    border-radius: 0;
    border: none;
    background: #0a0a0f;
  }
  .viz-container:fullscreen .viz-controls {
    opacity: 1;
  }
  .viz-container.viz-controls-hidden .viz-controls {
    opacity: 0;
    pointer-events: none;
  }
  /* keyboard users tabbing into the controls must see them */
  .viz-container.viz-controls-hidden .viz-controls:focus-within {
    opacity: 1;
    pointer-events: auto;
  }

  /* Genre info overlay in fullscreen */
  .viz-genre-info {
    position: absolute;
    top: 1.5rem;
    left: 1.5rem;
    color: rgba(200, 200, 212, 0.6);
    font-size: 0.8rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
  }
  .viz-container:fullscreen .viz-genre-info {
    opacity: 1;
  }
  /* WebGL-failure notice must be readable outside fullscreen too — the
     double-class selector outranks the idle-hide rule below */
  .viz-container.viz-failed .viz-genre-info,
  .viz-container.viz-failed.viz-controls-hidden .viz-genre-info {
    opacity: 1;
  }
  .viz-container.viz-controls-hidden .viz-genre-info {
    opacity: 0;
  }

  /* ── Advanced panel ── */
  .adv-section {
    width: 100%;
    max-width: 500px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
  }

  .adv-toggle {
    background: var(--surface);
    color: var(--text-dim);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 12px;
    padding: 0.65rem 1.4rem;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    cursor: pointer;
    transition: all 0.25s ease;
  }
  .adv-toggle:hover {
    color: var(--text);
    border-color: var(--accent2);
    box-shadow: 0 0 16px var(--glow-blue);
  }
  .adv-toggle.open {
    color: #fff;
    border-color: var(--accent);
    box-shadow: 0 0 20px var(--glow-pink);
  }
  .adv-caret { display: inline-block; transition: transform 0.25s ease; }
  .adv-toggle.open .adv-caret { transform: rotate(180deg); }

  .adv-panel {
    width: 100%;
    background: var(--surface);
    border: 1px solid rgba(255,255,255,0.06);
    border-radius: 20px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
    animation: adv-fade-in 0.3s ease;
  }
  .adv-panel[hidden] { display: none; }

  @keyframes adv-fade-in {
    from { opacity: 0; transform: translateY(-6px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .adv-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }
  .adv-group h3 {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--text-dim);
    border-bottom: 1px solid rgba(255,255,255,0.06);
    padding-bottom: 0.5rem;
  }
  .adv-group .control-label span:first-child {
    font-size: 0.8rem;
  }

  .adv-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
  }
  .adv-row label {
    color: var(--text-dim);
    font-size: 0.85rem;
    font-weight: 500;
    min-width: 110px;
  }
  .adv-row select {
    flex: 1;
    background: var(--surface2);
    color: var(--text);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 6px;
    padding: 0.4rem 0.6rem;
    font-size: 0.9rem;
    font-family: inherit;
  }
  .adv-row select:focus {
    outline: none;
    border-color: var(--accent2);
    box-shadow: 0 0 8px var(--glow-blue);
  }

  .adv-hint {
    font-size: 0.75rem;
    color: var(--text-dim);
    opacity: 0.8;
  }

  .adv-check {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.85rem;
    color: var(--text);
    cursor: pointer;
  }
  .adv-check input[type="checkbox"] {
    width: 18px; height: 18px;
    accent-color: var(--accent);
    cursor: pointer;
  }

  .adv-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
  }
  .adv-btn {
    background: var(--surface2);
    color: var(--text);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 10px;
    padding: 0.55rem 1.2rem;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s ease;
  }
  .adv-btn:hover {
    border-color: var(--accent);
    box-shadow: 0 0 16px var(--glow-pink);
  }
  .adv-btn.recording {
    color: #fff;
    border-color: #ff4b4b;
    box-shadow: 0 0 16px rgba(255,75,75,0.5);
    animation: rec-pulse 1.2s ease-in-out infinite;
  }
  @keyframes rec-pulse {
    0%, 100% { box-shadow: 0 0 10px rgba(255,75,75,0.35); }
    50% { box-shadow: 0 0 22px rgba(255,75,75,0.65); }
  }
  .adv-btn-dim { color: var(--text-dim); }

  /* Responsive */
  @media (max-width: 500px) {
    .container { padding: 1.5rem 1rem; }
    header h1 { font-size: 1.8rem; }
    .controls { padding: 1.5rem; }
    .viz-container { height: 150px; }
    .adv-row { flex-direction: column; align-items: stretch; gap: 0.35rem; }
    .adv-row label { min-width: 0; }
  }