/* ==========================================================================
   VALENCE — Modern Industrial Dark Aesthetic Design System
   ========================================================================== */

:root {
  --bg: #050b14;
  --bg-subtle: #08111f;
  --bg-card: rgba(12, 23, 41, 0.72);
  --bg-card-hover: rgba(18, 33, 58, 0.85);
  --border: rgba(255, 255, 255, 0.08);
  --border-highlight: rgba(56, 189, 248, 0.28);
  
  --text-main: #f1f6fc;
  --text-muted: #8fa5bc;
  --text-dim: #5c728a;
  
  /* Chemical / Quantum Accent Palette */
  --cyan: #22d3ee;
  --blue: #38bdf8;
  --indigo: #818cf8;
  --violet: #a78bfa;
  --amber: #f59e0b;
  --emerald: #10b981;
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 30px;
  
  --shell: min(1200px, calc(100vw - 48px));
  --font-sans: 'Plus Jakarta Sans', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  --transition: all 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  color-scheme: dark;
  background-color: var(--bg);
}

body {
  font-family: var(--font-sans);
  color: var(--text-main);
  background-color: var(--bg);
  background-image: 
    radial-gradient(ellipse at 15% 0%, rgba(34, 211, 238, 0.07), transparent 45%),
    radial-gradient(ellipse at 85% 15%, rgba(129, 140, 248, 0.08), transparent 50%),
    radial-gradient(circle at 50% 60%, rgba(56, 189, 248, 0.03), transparent 60%);
  background-attachment: fixed;
  line-height: 1.65;
  font-size: 15px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.shell {
  width: var(--shell);
  margin-left: auto;
  margin-right: auto;
}

/* Background Texture & Ambient Lights */
.noise {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
}

.ambient-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
}

.g1 {
  width: 500px;
  height: 500px;
  top: -150px;
  left: 5%;
  background: radial-gradient(circle, rgba(34, 211, 238, 0.22), transparent 70%);
}

.g2 {
  width: 600px;
  height: 600px;
  top: 30%;
  right: -200px;
  background: radial-gradient(circle, rgba(129, 140, 248, 0.16), transparent 70%);
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.nav {
  height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(5, 11, 20, 0.78);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: #fff;
}

.brand-text {
  font-weight: 800;
  letter-spacing: 0.18em;
  font-size: 15px;
  background: linear-gradient(90deg, #ffffff, #d2e4fc);
  -webkit-background-clip: text;
  color: transparent;
}

/* Chemical Molecule Logo Mark */
.mark {
  width: 32px;
  height: 32px;
  position: relative;
  display: inline-block;
}

.atom {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 14px rgba(34, 211, 238, 0.8);
  transition: transform 0.3s ease;
}

.a1 { left: 2px; top: 4px; }
.a2 { right: 2px; top: 5px; }
.a3 { left: 12px; bottom: 2px; }
.a4 { left: 14px; top: 9px; background: var(--indigo); box-shadow: 0 0 14px rgba(129, 140, 248, 0.8); }

.bond {
  position: absolute;
  height: 1.5px;
  background: rgba(255, 255, 255, 0.4);
  transform-origin: left center;
}

.b1 { width: 19px; left: 6px; top: 8px; transform: rotate(3deg); }
.b2 { width: 18px; left: 6px; top: 8px; transform: rotate(62deg); }
.b3 { width: 17px; left: 22px; top: 8px; transform: rotate(128deg); }

.brand:hover .atom {
  transform: scale(1.18);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
  padding: 6px 0;
}

.nav-links a:hover,
.nav-links a.active {
  color: #fff;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--cyan);
  transition: var(--transition);
  border-radius: 2px;
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* Language Switcher */
.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
}

.lang-btn {
  background: transparent;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  padding: 2px 5px;
  font-size: 12px;
  font-weight: 600;
  transition: var(--transition);
  border-radius: 4px;
}

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

.lang-btn.active {
  color: var(--cyan);
  font-weight: 700;
}

.lang-divider {
  color: rgba(255, 255, 255, 0.15);
}

.nav-cta {
  padding: 8px 18px;
  border: 1px solid rgba(56, 189, 248, 0.35);
  border-radius: 999px;
  color: #fff;
  background: rgba(56, 189, 248, 0.08);
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
  transition: var(--transition);
}

.nav-cta:hover {
  background: var(--blue);
  color: #04101e;
  box-shadow: 0 0 20px rgba(56, 189, 248, 0.4);
}

.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.mobile-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  transition: var(--transition);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
  min-height: calc(90vh - 76px);
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 40px;
  padding: 60px 0 60px;
  position: relative;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--cyan);
  text-transform: uppercase;
  margin-bottom: 20px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.hero h1 {
  font-size: clamp(40px, 5.5vw, 68px);
  line-height: 1.08;
  font-weight: 800;
  letter-spacing: -0.035em;
  margin-bottom: 22px;
}

.gradient-text {
  background: linear-gradient(135deg, #ffffff 10%, #7dd3fc 50%, #a78bfa 100%);
  -webkit-background-clip: text;
  color: transparent;
}

.lead {
  font-size: 18px;
  line-height: 1.7;
  color: var(--text-muted);
  max-width: 580px;
  margin-bottom: 34px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 38px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
}

.btn.primary {
  background: linear-gradient(135deg, var(--cyan), #38bdf8);
  color: #04101e;
  box-shadow: 0 8px 24px rgba(34, 211, 238, 0.25);
}

.btn.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(34, 211, 238, 0.38);
}

.btn.ghost {
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.04);
  color: #fff;
}

.btn.ghost:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 15px 30px;
  font-size: 15px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid var(--border);
  padding: 6px 12px;
  border-radius: 999px;
  font-weight: 500;
}

.tag .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

/* Molecule Stage Visual */
.molecule-stage {
  height: 500px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.orbital-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px dashed rgba(56, 189, 248, 0.2);
  transform-origin: center center;
}

.ring-outer {
  width: 440px;
  height: 440px;
  animation: spin 60s linear infinite;
}

.ring-mid {
  width: 320px;
  height: 320px;
  border-color: rgba(129, 140, 248, 0.25);
  animation: spinReverse 40s linear infinite;
}

.ring-inner {
  width: 200px;
  height: 200px;
  border-color: rgba(34, 211, 238, 0.35);
  animation: spin 24s linear infinite;
}

.core-nucleus {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #38bdf8, #0e3a60 70%, #06182c 100%);
  display: grid;
  place-items: center;
  position: relative;
  box-shadow: 0 0 60px rgba(56, 189, 248, 0.35);
  z-index: 5;
}

.core-letter {
  font-size: 46px;
  font-weight: 800;
  color: #ffffff;
  text-shadow: 0 2px 10px rgba(0,0,0,0.5);
}

.core-pulse {
  position: absolute;
  inset: -12px;
  border-radius: 50%;
  border: 1px solid rgba(56, 189, 248, 0.4);
  animation: pulseGlow 3s ease-in-out infinite;
}

/* Floating Interactive Nodes */
.node-cluster {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: rgba(11, 23, 40, 0.85);
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-md);
  backdrop-filter: blur(14px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
  z-index: 6;
  transition: transform 0.3s ease;
}

.node-cluster:hover {
  transform: scale(1.08);
}

.node-icon {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 13px;
}

.node-info b {
  display: block;
  font-size: 12px;
  letter-spacing: 0.05em;
  color: #fff;
}

.node-info small {
  font-size: 10px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.node-ion {
  left: 2%;
  top: 62%;
}
.node-ion .node-icon { background: rgba(56, 189, 248, 0.2); color: var(--blue); }

.node-catalyst {
  right: 4%;
  top: 18%;
}
.node-catalyst .node-icon { background: rgba(167, 139, 250, 0.2); color: var(--violet); }

.node-reactor {
  right: 2%;
  bottom: 12%;
}
.node-reactor .node-icon { background: rgba(245, 158, 11, 0.2); color: var(--amber); }

.molecule-flux {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 4;
}

.flux-line {
  fill: none;
  stroke: rgba(56, 189, 248, 0.4);
  stroke-width: 2;
  stroke-dasharray: 6 10;
  animation: fluxFlow 12s linear infinite;
}

.line-2 { stroke: rgba(167, 139, 250, 0.4); animation-duration: 15s; }
.line-3 { stroke: rgba(245, 158, 11, 0.4); animation-duration: 10s; }

/* ==========================================================================
   Common Section Styles
   ========================================================================== */

.section {
  padding: 100px 0;
  position: relative;
}

.section-head {
  max-width: 800px;
  margin-bottom: 56px;
}

.section-head h2 {
  font-size: clamp(32px, 4vw, 48px);
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin: 12px 0 16px;
}

.subtitle {
  font-size: 17px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   Section 1: Reaction Chain Story
   ========================================================================== */

.reaction-chain {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr;
  align-items: stretch;
  gap: 16px;
}

.step {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
  transition: var(--transition);
}

.step:hover {
  background: var(--bg-card-hover);
  border-color: rgba(255, 255, 255, 0.16);
  transform: translateY(-4px);
}

.step-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.step-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
}

.step-badge {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-size: 20px;
  font-weight: 800;
}

.ion-badge { background: rgba(56, 189, 248, 0.12); color: var(--blue); border: 1px solid rgba(56, 189, 248, 0.3); }
.valence-badge { background: rgba(34, 211, 238, 0.12); color: var(--cyan); border: 1px solid rgba(34, 211, 238, 0.3); }
.catalyst-badge { background: rgba(167, 139, 250, 0.12); color: var(--violet); border: 1px solid rgba(167, 139, 250, 0.3); }
.reactor-badge { background: rgba(245, 158, 11, 0.12); color: var(--amber); border: 1px solid rgba(245, 158, 11, 0.3); }

.step h3 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 4px;
}

.step-tagline {
  font-size: 12px;
  color: var(--cyan);
  font-family: var(--font-mono);
  margin-bottom: 14px;
}

.step-desc {
  font-size: 13.5px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 24px;
  flex-grow: 1;
}

.step-footer-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

.step-footer-tags span {
  font-size: 11px;
  color: var(--text-dim);
  background: rgba(255, 255, 255, 0.03);
  padding: 4px 8px;
  border-radius: 6px;
}

.chain-arrow {
  display: grid;
  place-items: center;
  color: rgba(255, 255, 255, 0.18);
  width: 24px;
}

.chain-arrow svg {
  width: 24px;
  height: 24px;
}

/* ==========================================================================
   Section 2: Products Family
   ========================================================================== */

.product-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.product-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 38px 36px 32px;
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.product-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(255, 255, 255, 0.18);
  transform: translateY(-4px);
}

.product-card .card-glow {
  position: absolute;
  width: 300px;
  height: 300px;
  right: -100px;
  top: -100px;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
  opacity: 0.15;
}

.ion-card .card-glow { background: var(--blue); }
.valence-card .card-glow { background: var(--cyan); }
.catalyst-card .card-glow { background: var(--violet); }
.reactor-card .card-glow { background: var(--amber); }

.product-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.pill {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding: 5px 12px;
  border-radius: 999px;
}

.pill-blue { background: rgba(56, 189, 248, 0.15); color: var(--blue); }
.pill-cyan { background: rgba(34, 211, 238, 0.15); color: var(--cyan); }
.pill-violet { background: rgba(167, 139, 250, 0.15); color: var(--violet); }
.pill-amber { background: rgba(245, 158, 11, 0.15); color: var(--amber); }

.card-index {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-dim);
}

.product-card h3 {
  font-size: 38px;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 4px;
}

.product-card h4 {
  font-size: 16px;
  font-weight: 600;
  color: #cbd5e1;
  margin-bottom: 16px;
}

.product-card > p {
  color: var(--text-muted);
  font-size: 14.5px;
  line-height: 1.65;
  margin-bottom: 24px;
}

.feature-list {
  list-style: none;
  margin-bottom: 30px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.feature-list li {
  font-size: 13.5px;
  color: #94a3b8;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.feature-list li::before {
  content: '▸';
  color: var(--cyan);
  font-size: 14px;
  line-height: 1.4;
}

/* Product Visuals */
.card-visual {
  margin-top: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: rgba(4, 9, 18, 0.6);
  padding: 16px 20px;
  overflow: hidden;
}

/* Visual 1: Bars */
.visual-bars {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.bar-chart {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  height: 70px;
}

.bar {
  width: 24px;
  background: linear-gradient(180deg, var(--blue), rgba(56, 189, 248, 0.15));
  border-radius: 4px 4px 1px 1px;
  display: flex;
  justify-content: center;
  align-items: flex-end;
  position: relative;
  animation: barPulse 3.5s ease-in-out infinite alternate;
}

.bar small {
  position: absolute;
  bottom: -20px;
  font-size: 9px;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

.b1 { height: 42px; animation-delay: 0.1s; }
.b2 { height: 62px; animation-delay: 0.4s; }
.b3 { height: 35px; animation-delay: 0.7s; }
.b4 { height: 55px; animation-delay: 0.2s; }
.b5 { height: 48px; animation-delay: 0.5s; }

.visual-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--blue);
  background: rgba(56, 189, 248, 0.1);
  padding: 6px 12px;
  border-radius: 999px;
}

/* Visual 2: Network */
.visual-network {
  position: relative;
  height: 90px;
}

.net-node {
  position: absolute;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(34, 211, 238, 0.15);
  border: 1px solid rgba(34, 211, 238, 0.4);
  font-size: 10px;
  color: var(--cyan);
  font-family: var(--font-mono);
  z-index: 2;
}

.n-core { left: 40%; top: 32%; background: var(--cyan); color: #04101e; font-weight: 700; }
.n1 { left: 8%; top: 32%; }
.n2 { left: 24%; top: 8%; }
.n3 { right: 8%; top: 32%; }
.n4 { right: 24%; bottom: 8%; }

.net-lines {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  stroke: rgba(34, 211, 238, 0.3);
  stroke-width: 1.5;
  stroke-dasharray: 3 3;
}

/* Visual 3: Terminal */
.visual-terminal {
  font-family: var(--font-mono);
  font-size: 11.5px;
}

.terminal-header {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border);
}

.t-dot { width: 8px; height: 8px; border-radius: 50%; }
.t-dot.red { background: #ef4444; }
.t-dot.yellow { background: #f59e0b; }
.t-dot.green { background: #10b981; }

.t-title {
  color: var(--text-dim);
  font-size: 10px;
  margin-left: 6px;
}

.t-prompt {
  display: block;
  color: var(--violet);
  margin-bottom: 4px;
}

.t-status {
  display: block;
  color: var(--emerald);
}

/* Visual 4: Waveform */
.visual-waveform {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.wave-status {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
}

.wave-tag {
  color: var(--amber);
  display: flex;
  align-items: center;
  gap: 6px;
}

.pulse-indicator {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
  animation: blink 1.2s ease-in-out infinite;
}

.wave-metric {
  color: var(--emerald);
  font-weight: 700;
}

.wave-svg {
  width: 100%;
  height: 40px;
  stroke: var(--amber);
  stroke-width: 2;
  fill: none;
}

/* ==========================================================================
   Section 3: Scenarios Grid
   ========================================================================== */

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.scenario-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  transition: var(--transition);
}

.scenario-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(255, 255, 255, 0.16);
  transform: translateY(-4px);
}

.scenario-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.scenario-idx {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
}

.scenario-icon {
  font-size: 24px;
}

.scenario-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
  color: #f8fafc;
}

.scenario-card p {
  font-size: 13.5px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   Section 4: Architecture Closed Loop
   ========================================================================== */

.architecture-box {
  background: linear-gradient(135deg, rgba(14, 26, 46, 0.8), rgba(8, 16, 29, 0.9));
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-xl);
  padding: 56px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: 48px;
  position: relative;
  overflow: hidden;
}

.arch-content h2 {
  font-size: clamp(30px, 3.5vw, 42px);
  line-height: 1.15;
  font-weight: 800;
  margin: 12px 0 18px;
}

.arch-lead {
  font-size: 15.5px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 36px;
}

.arch-bullets {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.bullet-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.bullet-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan);
  background: rgba(34, 211, 238, 0.1);
  padding: 4px 8px;
  border-radius: 6px;
}

.bullet-item b {
  display: block;
  font-size: 15px;
  color: #fff;
  margin-bottom: 4px;
}

.bullet-item p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* Architecture Visual Loop */
.arch-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.closed-loop-wrapper {
  width: 340px;
  height: 340px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.loop-track {
  position: absolute;
  inset: 20px;
  border-radius: 50%;
  border: 2px dashed rgba(34, 211, 238, 0.3);
  box-shadow: 0 0 60px rgba(34, 211, 238, 0.08) inset;
  animation: spin 35s linear infinite;
}

.loop-node {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-family: var(--font-mono);
  color: #cbd5e1;
  background: rgba(11, 23, 40, 0.9);
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
}

.loop-node .n-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

.ln-1 { top: 0; left: 50%; transform: translateX(-50%); }
.ln-2 { top: 25%; right: -5%; }
.ln-3 { bottom: 12%; right: 4%; }
.ln-4 { bottom: 12%; left: 4%; }
.ln-5 { top: 25%; left: -5%; }

.loop-center {
  text-align: center;
  z-index: 2;
}

.loop-center b {
  font-size: 24px;
  font-weight: 800;
  letter-spacing: 0.1em;
  display: block;
  background: linear-gradient(90deg, #fff, var(--cyan));
  -webkit-background-clip: text;
  color: transparent;
}

.loop-center small {
  font-size: 11px;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* ==========================================================================
   Section 5: Closing CTA
   ========================================================================== */

.closing {
  text-align: center;
  padding: 120px 0 140px;
}

.closing-content {
  max-width: 760px;
  margin: 0 auto;
}

.closing h2 {
  font-size: clamp(36px, 4.5vw, 56px);
  font-weight: 800;
  letter-spacing: -0.035em;
  margin: 14px 0 18px;
}

.closing p {
  font-size: 18px;
  color: var(--text-muted);
  margin-bottom: 40px;
}

.closing-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.footer {
  border-top: 1px solid var(--border);
  padding: 60px 0 40px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
}

.brand-col .f-brand b {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: 0.15em;
  color: #fff;
}

.f-desc {
  font-size: 13px;
  color: var(--text-dim);
  max-width: 320px;
  margin-top: 12px;
}

.f-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.f-title {
  font-size: 12px;
  font-weight: 700;
  font-family: var(--font-mono);
  color: #cbd5e1;
  margin-bottom: 6px;
  letter-spacing: 0.05em;
}

.f-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 13px;
  transition: var(--transition);
}

.f-links a:hover {
  color: var(--cyan);
}

.footer-bottom {
  grid-column: 1 / -1;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  display: flex;
  justify-content: space-between;
  color: var(--text-dim);
  font-size: 12px;
  font-family: var(--font-mono);
}

/* ==========================================================================
   Animations & Reveals
   ========================================================================== */

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.75s cubic-bezier(0.16, 1, 0.3, 1), transform 0.75s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes spinReverse {
  from { transform: rotate(360deg); }
  to { transform: rotate(0deg); }
}

@keyframes fluxFlow {
  to { stroke-dashoffset: -200; }
}

@keyframes pulseGlow {
  0%, 100% { transform: scale(1); opacity: 0.4; }
  50% { transform: scale(1.15); opacity: 0.8; }
}

@keyframes barPulse {
  0% { transform: scaleY(0.75); }
  100% { transform: scaleY(1.05); }
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */

@media (max-width: 1024px) {
  .hero {
    grid-template-columns: 1fr;
    padding-top: 40px;
  }
  
  .molecule-stage {
    height: 420px;
    margin-top: 20px;
  }

  .reaction-chain {
    grid-template-columns: 1fr 1fr;
  }
  
  .chain-arrow {
    display: none;
  }

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

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

  .architecture-box {
    grid-template-columns: 1fr;
    padding: 40px 30px;
  }

  .arch-visual {
    margin-top: 30px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 76px;
    left: 0;
    right: 0;
    background: rgba(5, 11, 20, 0.96);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 24px;
    border-bottom: 1px solid var(--border);
    gap: 20px;
  }

  .nav-links.open {
    display: flex;
  }

  .mobile-toggle {
    display: flex;
  }

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

  .reaction-chain {
    grid-template-columns: 1fr;
  }

  .footer {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 10px;
  }

  .closing-actions {
    flex-direction: column;
    width: 100%;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }
}

/* ===== 2026-08-21 header cleanup ===== */

/* 顶部导航不再使用黑色条状背景 */
.nav {
  background: transparent !important;
  backdrop-filter: none !important;
  -webkit-backdrop-filter: none !important;
  border-bottom: none !important;
  box-shadow: none !important;
}

/* 去掉中英文切换和联系我们 */
.lang-switch,
.nav-cta {
  display: none !important;
}

/* 顶部保持干净 */
.nav-actions {
  gap: 0 !important;
}


/* =========================================================
   VALENCE production hotfix
   ========================================================= */

/* 顶部不要黑色横条 */
.nav {
  background: transparent !important;
  background-color: transparent !important;
  backdrop-filter: none !important;
  -webkit-backdrop-filter: none !important;
  border-bottom: none !important;
  box-shadow: none !important;
}

/* 顶部导航保持正常字号，不放大 */
.nav-links a {
  font-size: 14px !important;
  font-weight: 500 !important;
  line-height: 1.4 !important;
  letter-spacing: 0 !important;
}

/* 不显示语言切换和联系我们 */
.lang-switch,
.nav-cta {
  display: none !important;
}

/* 防止之前 JS / IntersectionObserver 导致中间内容全部透明 */
.reveal,
.reveal.visible {
  opacity: 1 !important;
  visibility: visible !important;
  transform: none !important;
}

/* 所有主要 section 明确恢复显示 */
.story,
.products,
.scenarios,
.architecture,
.closing,
.reaction-chain,
.product-grid,
.scenario-grid,
.architecture-card {
  opacity: 1 !important;
  visibility: visible !important;
}

/* 顶部 action 区不再占多余空间 */
.nav-actions {
  gap: 0 !important;
}


/* 顶部导航不固定，随页面滚动 */
.nav {
  position: relative !important;
  top: auto !important;
  z-index: auto !important;
}

/* Logo 与顶部标题都不固定 */
.brand,
.nav-links,
.nav-actions {
  position: static !important;
}


/* 闭环说明文字与下方 01 卡片之间增加间距 */
.architecture-card .arch-copy,
.architecture .section-head,
.architecture-copy {
  margin-bottom: 48px !important;
}

/* 如果 01 是第一张能力卡，则再保证首卡顶部留白 */
.architecture-card .feature-list,
.architecture-card .architecture-features,
.architecture-card .arch-features {
  margin-top: 32px !important;
}


/* 默认：顶部不固定 */
.nav {
  position: relative !important;
  top: auto !important;
}

/* 点击顶部导航跳转后：临时固定 */
.nav.nav-pinned {
  position: fixed !important;
  top: 0 !important;
  left: 50% !important;
  transform: translateX(-50%) !important;
  width: var(--shell) !important;
  z-index: 1000 !important;

  background: rgba(5, 11, 20, 0.72) !important;
  backdrop-filter: blur(16px) !important;
  -webkit-backdrop-filter: blur(16px) !important;
  border-bottom: 1px solid rgba(255,255,255,.06) !important;
}

/* 固定状态下避免内容被顶栏遮住 */
body.nav-is-pinned main {
  padding-top: 76px;
}