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

:root {
  --bg: #1a1a2e;
  --surface: #16213e;
  --accent: #0f3460;
  --text: #e0e0e0;
  --text-dim: #8888aa;
  --primary: #e94560;
  --primary-hover: #ff6b81;
  --clock-brightness: 0.6;
  --clock-color: 255, 255, 255;
  --radius: 8px;
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
}

/* ===== Tab bar ===== */
#tab-bar {
  display: flex;
  background: var(--surface);
  border-bottom: 2px solid var(--accent);
  position: sticky;
  top: 0;
  z-index: 10;
  padding-top: env(safe-area-inset-top, 0px);
}

.tab {
  flex: 1;
  padding: 12px 0;
  border: none;
  background: transparent;
  color: var(--text-dim);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.2s, border-bottom 0.2s;
  border-bottom: 3px solid transparent;
}
.tab:hover { color: var(--text); }
.tab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

/* ===== Panels ===== */
.panel {
  display: none;
  padding: 24px 20px;
  max-width: 900px;
  margin: 0 auto;
}
.panel.active { display: block; }

.panel h2 {
  margin-bottom: 20px;
  font-size: 1.4rem;
}

/* ===== Controls ===== */
.control-group {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.control-group label {
  min-width: 80px;
  font-size: 0.9rem;
  color: var(--text-dim);
}

select, input[type="range"] {
  accent-color: var(--primary);
}

select {
  background: var(--accent);
  color: var(--text);
  border: 1px solid #334;
  border-radius: var(--radius);
  padding: 6px 10px;
  font-size: 0.9rem;
}

input[type="range"] {
  width: 180px;
  cursor: pointer;
}

input[type="range"]:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.status-message {
  min-height: 1.25rem;
  margin: -6px 0 10px;
  color: var(--primary-hover);
  font-size: 0.85rem;
}

/* ===== Buttons ===== */
.btn-primary {
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 10px 24px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}
.btn-primary:hover { background: var(--primary-hover); }

.btn-sm {
  background: var(--accent);
  color: var(--text-dim);
  border: 1px solid #334;
  border-radius: var(--radius);
  padding: 6px 14px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-sm.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* ===== Viz ===== */
.viz-toggle {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

#viz-canvas,
#noise-canvas {
  width: 100%;
  max-width: 800px;
  height: 200px;
  background: #0d0d1a;
  border-radius: var(--radius);
  margin-bottom: 16px;
}

/* ===== Sine sliders grid ===== */
#sine-sliders {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 10px;
}

.sine-row {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 8px 12px;
  font-size: 0.82rem;
}
.sine-row .label { min-width: 28px; color: var(--text-dim); font-weight: 600; }
.sine-row input[type="range"] { width: 100px; }
.sine-row .value { min-width: 55px; text-align: right; color: var(--text-dim); font-variant-numeric: tabular-nums; }

/* ===== Clock overlay ===== */
#clock-overlay {
  position: fixed;
  inset: 0;
  background: #000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 100;
  cursor: pointer;
}
#clock-overlay.hidden { display: none; }

#clock-display {
  font-family: 'SF Mono', 'Cascadia Code', 'Fira Code', monospace;
  font-size: clamp(4rem, 18vw, 14rem);
  font-weight: 200;
  color: rgba(var(--clock-color), var(--clock-brightness));
  letter-spacing: 0.05em;
  user-select: none;
}

#clock-exit-hint {
  margin-top: 20px;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.15);
  text-transform: uppercase;
  letter-spacing: 0.15em;
}

.clock-settings {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 400px;
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .panel { padding: 16px 12px; }
  #sine-sliders { grid-template-columns: 1fr; }
  .sine-row input[type="range"] { width: 70px; }
}