/* ══════════════════════════════════════════════
   Frozen Substrate Section Styles
   ══════════════════════════════════════════════ */

.substrate-section {
  position: relative;
  z-index: 10;
  background: var(--bg);
  padding: 80px 24px 100px;
  max-width: 100vw;
  overflow: hidden;
}
.substrate-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.substrate-header {
  text-align: center;
  margin-bottom: 32px;
}

/* Flow diagram */
.flow-diagram {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 24px;
  opacity: 0;
  transform: translateY(15px);
}
.flow-diagram.visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.6s ease 0.1s, transform 0.6s ease 0.1s;
}
.flow-node {
  font-size: 0.65rem;
  font-weight: 400;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 4px 10px;
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 4px;
  color: rgba(255,255,255,0.55);
  white-space: nowrap;
}
.flow-node.fl-active {
  border-color: rgba(255,107,53,0.4);
  color: var(--accent);
}
.flow-arrow {
  color: rgba(255,255,255,0.22);
  font-size: 0.7rem;
}

/* L0 input box */
.sub-l0-row {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 20px;
}
.sub-l0-box {
  position: relative;
  flex: 0 0 auto;
  background: rgba(0,0,0,0.35);
  border: 1px solid rgba(255,107,53,0.2);
  border-radius: 10px;
  padding: 10px;
}
#sub-l0-canvas {
  display: block;
  border-radius: 4px;
  cursor: crosshair;
  image-rendering: pixelated;
}
.sub-l0-label {
  text-align: center;
  margin-top: 6px;
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
}
.sub-l0-hint {
  position: absolute;
  inset: 10px;
  bottom: auto;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  border-radius: 4px;
  aspect-ratio: 1;
}
.sub-l0-hint span {
  font-size: 0.65rem;
  font-weight: 300;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: rgba(255,107,53,0.5);
  text-shadow: 0 0 12px rgba(255,107,53,0.2);
  transition: opacity 0.6s ease;
}
.sub-l0-hint.hidden span { opacity: 0; }
.sub-l0-arrow {
  flex: 0 0 auto;
  font-size: 1.4rem;
  color: rgba(255,107,53,0.25);
}

/* 3D depth visualization */
.sub-3d-wrap {
  flex: 1;
  min-width: 0;
  position: relative;
  aspect-ratio: 16 / 9;
  background: rgba(0,0,0,0.3);
  border: 1px solid rgba(255,255,255,0.04);
  border-radius: 12px;
  overflow: hidden;
}
.sub-3d-wrap canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* Depth meter */
.sub-depth-meter { margin: 16px 0; padding: 0 16px; }
.sub-depth-meter .bar-bg {
  height: 4px;
  background: rgba(255,255,255,0.04);
  border-radius: 2px;
  overflow: hidden;
}
.sub-depth-meter .bar-fill {
  height: 100%;
  border-radius: 2px;
  transition: width 0.3s;
  background: linear-gradient(90deg, var(--accent), rgba(255,255,255,0.2));
}
.sub-depth-meter .meter-label {
  display: flex;
  justify-content: space-between;
  margin-top: 4px;
}
.sub-depth-meter .meter-label span {
  font-size: 0.55rem;
  color: rgba(255,255,255,0.25);
  letter-spacing: 0.1em;
}

/* Stats */
.sub-stats {
  display: flex;
  gap: 24px;
  justify-content: center;
  margin: 16px 0;
}
.sub-stat { text-align: center; }
.sub-stat .val {
  font-size: 1.2rem;
  font-weight: 300;
  font-variant-numeric: tabular-nums;
  color: rgba(255,255,255,0.55);
}
.sub-stat.s-depth .val { color: var(--accent); }
.sub-stat.s-coherence .val { color: rgba(255,160,100,0.75); }
.sub-stat.s-fps .val { color: rgba(255,255,255,0.38); }
.sub-stat .stat-label {
  font-size: 0.55rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.25);
}

/* Controls */
.sub-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  margin: 16px 0;
}
.sub-controls .hint {
  font-size: 0.7rem;
  color: rgba(255,255,255,0.3);
}
.sub-controls .hint b {
  color: rgba(255,255,255,0.45);
  font-weight: 400;
}
.sub-btn {
  background: transparent;
  color: rgba(255,255,255,0.38);
  border: 1px solid rgba(255,255,255,0.10);
  padding: 5px 14px;
  border-radius: 4px;
  font-size: 0.7rem;
  font-family: 'Inter', system-ui, sans-serif;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: all 0.2s;
}
.sub-btn:hover {
  border-color: rgba(255,255,255,0.18);
  color: rgba(255,255,255,0.6);
}
.sub-btn.active {
  border-color: rgba(255,107,53,0.35);
  color: var(--accent);
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .substrate-section { padding: 60px 16px 80px; }
}
@media (max-width: 600px) {
  .sub-l0-row { flex-direction: column; gap: 10px; }
  .sub-3d-wrap { aspect-ratio: 4 / 3; }
  .sub-stats { flex-wrap: wrap; gap: 16px; }
  .flow-diagram { gap: 4px; }
  .flow-node { font-size: 0.55rem; padding: 3px 6px; }
  .sub-controls { flex-direction: column; align-items: flex-start; }
}