/* ─── BrainWave - Dark Theme ─────────────────────────── */
:root {
  --bg: #0a0a0f;
  --surface: #12121a;
  --surface2: #1a1a28;
  --border: #2a2a3a;
  --text: #e0e0f0;
  --text-dim: #8888aa;
  --accent: #6c5ce7;
  --accent-glow: rgba(108, 92, 231, 0.3);
  --radius: 12px;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
}

#app {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 20px 40px;
}

/* ─── Header ─────────────────────────────────────────── */
header {
  text-align: center;
  margin-bottom: 24px;
}

header h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, var(--accent), #a29bfe, #fd79a8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  color: var(--text-dim);
  font-size: 0.85rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-top: 2px;
}

/* ─── Visualizer ─────────────────────────────────────── */
#visualizer-container {
  position: relative;
  width: 100%;
  height: 160px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 20px;
}

#visualizer {
  width: 100%;
  height: 100%;
  display: block;
}

#status-overlay {
  position: absolute;
  top: 12px;
  left: 16px;
  display: flex;
  gap: 16px;
  align-items: center;
  pointer-events: none;
}

#status-text {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  text-shadow: 0 0 12px var(--accent-glow);
}

#freq-display {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: 'SF Mono', 'Fira Code', monospace;
}

/* ─── Master Controls ────────────────────────────────── */
#master-controls {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 16px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.btn-primary {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 2px solid var(--accent);
  background: transparent;
  color: var(--accent);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
  flex-shrink: 0;
}

.btn-primary:hover {
  background: var(--accent);
  color: var(--bg);
  box-shadow: 0 0 24px var(--accent-glow);
}

.btn-primary.playing {
  background: var(--accent);
  color: var(--bg);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 8px var(--accent-glow); }
  50% { box-shadow: 0 0 28px var(--accent-glow); }
}

.volume-control, #timer-section {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 160px;
}

.volume-control label, #timer-section label {
  font-size: 0.8rem;
  color: var(--text-dim);
  white-space: nowrap;
}

#volume-value, .sound-value, .wave-value {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: 'SF Mono', 'Fira Code', monospace;
  min-width: 40px;
}

#timer-select {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 8px;
  font-size: 0.8rem;
  cursor: pointer;
}

#timer-display {
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 0.85rem;
  color: var(--accent);
  min-width: 50px;
}

/* ─── Range Inputs ───────────────────────────────────── */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--surface2);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 8px var(--accent-glow);
  cursor: pointer;
}

input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 8px var(--accent-glow);
  cursor: pointer;
}

/* ─── Tabs ───────────────────────────────────────────── */
#tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0;
}

.tab {
  flex: 1;
  padding: 10px 8px;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 0.85rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
  font-weight: 500;
}

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

.tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeIn 0.25s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ─── Mode Cards ─────────────────────────────────────── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 12px;
}

.mode-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
  color: var(--text);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.mode-card:hover {
  border-color: var(--accent);
  background: var(--surface2);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.mode-card.selected {
  border-color: var(--accent);
  background: var(--surface2);
  box-shadow: 0 0 20px var(--accent-glow), inset 0 0 20px rgba(108, 92, 231, 0.05);
}

.mode-icon {
  font-size: 1.8rem;
  line-height: 1;
  margin-bottom: 4px;
}

.mode-card h3 {
  font-size: 1rem;
  font-weight: 600;
}

.mode-card p {
  font-size: 0.78rem;
  color: var(--text-dim);
  line-height: 1.4;
}

.mode-tag {
  display: inline-block;
  margin-top: 4px;
  font-size: 0.68rem;
  padding: 3px 8px;
  background: var(--accent-glow);
  color: var(--accent);
  border-radius: 20px;
  width: fit-content;
  font-family: 'SF Mono', 'Fira Code', monospace;
}

/* ─── Brainwave Controls ─────────────────────────────── */
.brainwave-controls {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 24px;
}

.wave-band {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  transition: border-color 0.2s;
}

.wave-band.active-band {
  border-color: var(--accent);
  box-shadow: 0 0 12px var(--accent-glow);
}

.wave-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}

.wave-name {
  font-weight: 600;
  font-size: 0.95rem;
}

.wave-range {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: 'SF Mono', 'Fira Code', monospace;
}

.wave-desc {
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-left: auto;
}

.wave-band .wave-slider {
  margin-bottom: 6px;
}

/* ─── Tone Type Selector ─────────────────────────────── */
.tone-type-selector {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.tone-type-selector > label {
  font-size: 0.85rem;
  color: var(--text-dim);
  display: block;
  margin-bottom: 10px;
}

.radio-group {
  display: flex;
  gap: 24px;
  margin-bottom: 16px;
}

.radio-group label {
  font-size: 0.85rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
}

input[type="radio"] {
  accent-color: var(--accent);
}

.carrier-freq {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.carrier-freq label {
  font-size: 0.8rem;
  color: var(--text-dim);
}

#carrier-value {
  color: var(--accent);
  font-family: 'SF Mono', 'Fira Code', monospace;
}

/* ─── Sound Layers ───────────────────────────────────── */

/* ─── Music Controls ─────────────────────────────────── */
.music-controls {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.music-style-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 10px;
}

.music-style-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
  color: var(--text);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.music-style-btn:hover {
  border-color: var(--accent);
  background: var(--surface2);
  transform: translateY(-1px);
}

.music-style-btn.selected {
  border-color: var(--accent);
  background: var(--surface2);
  box-shadow: 0 0 16px var(--accent-glow);
}

.ms-icon {
  font-size: 1.4rem;
  line-height: 1;
  margin-bottom: 2px;
}

.ms-label {
  font-size: 0.85rem;
  font-weight: 600;
}

.ms-desc {
  font-size: 0.7rem;
  color: var(--text-dim);
  line-height: 1.3;
}

.music-volume-control {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.music-volume-control label {
  font-size: 0.85rem;
  font-weight: 500;
  min-width: 100px;
}

#music-volume {
  flex: 1;
}

#music-volume-value {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: 'SF Mono', 'Fira Code', monospace;
  min-width: 40px;
}

/* ─── Sound Layers (continued) ───────────────────────── */
.sound-layers {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.sound-layer {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.sound-name {
  font-size: 0.85rem;
  font-weight: 500;
  min-width: 110px;
}

.sound-slider {
  flex: 1;
}

/* ─── Custom Tab ─────────────────────────────────────── */
.custom-info {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 16px;
}

#custom-summary {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

#custom-summary p {
  font-size: 0.85rem;
  margin-bottom: 6px;
  color: var(--text-dim);
}

#custom-summary strong {
  color: var(--text);
}

/* ─── Footer ─────────────────────────────────────────── */
footer {
  margin-top: 32px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  text-align: center;
}

footer p {
  font-size: 0.72rem;
  color: var(--text-dim);
}

/* ─── Responsive ─────────────────────────────────────── */
@media (max-width: 600px) {
  #app {
    padding: 16px 12px 32px;
  }

  header h1 {
    font-size: 1.5rem;
  }

  #master-controls {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .btn-primary {
    align-self: center;
  }

  .volume-control, #timer-section {
    justify-content: center;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .wave-header {
    flex-direction: column;
    gap: 2px;
  }

  .wave-desc {
    margin-left: 0;
  }

  .sound-layer {
    flex-wrap: wrap;
  }

  .sound-name {
    min-width: 100%;
  }

  .music-style-grid {
    grid-template-columns: 1fr 1fr;
  }

  .music-volume-control {
    flex-wrap: wrap;
  }

  .music-volume-control label {
    min-width: 100%;
  }
}