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

:root {
  --bg: #ffffff;
  --bg-alt: #fafafa;
  --text: #111111;
  --text-secondary: #888888;
  --text-tertiary: #aaaaaa;
  --border: #e8e8e8;
  --border-light: #f0f0f0;
  --accent: #f4821f;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

[data-theme="dark"] {
  --bg: #0a0a0a;
  --bg-alt: #111111;
  --text: #f0f0f0;
  --text-secondary: #888888;
  --text-tertiary: #555555;
  --border: #222222;
  --border-light: #1a1a1a;
}

html {
  scroll-behavior: auto;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Pinned scroll sequence (Apple-style) */
.pin-section {
  position: relative;
}

.pin-track {
  height: 500vh;
}

.pin-sticky {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  border-top: 1px solid var(--border-light);
}

.pin-layout {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  align-items: center;
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2.5rem;
  width: 100%;
}

.pin-copy {
  max-width: 420px;
}

.pin-step {
  display: block;
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--text-tertiary);
  margin-bottom: 1.25rem;
}

.pin-title {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 1rem;
  color: var(--text);
  transition: opacity 0.35s, transform 0.35s;
}

.pin-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  transition: opacity 0.35s, transform 0.35s;
}

.pin-copy.is-transitioning .pin-title,
.pin-copy.is-transitioning .pin-desc {
  opacity: 0;
  transform: translateY(12px);
}

.pin-stage {
  position: relative;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.cell-svg {
  width: 100%;
  max-width: 580px;
  height: auto;
  max-height: 72vh;
  display: block;
}

[data-theme="dark"] .cell-svg #layer-cell rect:nth-child(1) {
  fill: #2a2824;
  stroke: #4a4844;
}

[data-theme="dark"] .cell-svg #layer-cell rect:nth-child(2) {
  fill: #1a2018;
  stroke: #3a5040;
}

[data-theme="dark"] .cell-svg #chlInnerGrad stop:first-child {
  stop-color: #2a4a28;
}

[data-theme="dark"] .cell-svg #chlInnerGrad stop:last-child {
  stop-color: #1a3a18;
}

[data-theme="dark"] .cell-svg #cell-label {
  fill: #666;
}

.pin-dots {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  padding-bottom: 2rem;
}

.pin-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--border);
  transition: background 0.3s, transform 0.3s;
}

.pin-dot.active {
  background: var(--text);
  transform: scale(1.3);
}

.pin-end-tag {
  padding: 1.25rem 2.5rem;
  border-top: 1px solid var(--border-light);
}

@media (max-width: 768px) {
  .pin-track {
    height: 450vh;
  }

  .pin-layout {
    grid-template-columns: 1fr;
    padding: 5rem 1.25rem 0;
    align-content: center;
  }

  .pin-copy {
    order: 2;
    text-align: center;
    max-width: none;
    padding-bottom: 1rem;
  }

  .pin-stage {
    order: 1;
    max-height: 45vh;
  }

  .pin-dots {
    padding-bottom: 1.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .pin-track {
    height: auto;
  }

  .pin-sticky {
    position: relative;
    height: auto;
    min-height: 100vh;
  }
}

/* Announcement bar */
.announcement-bar {
  background: #000;
  color: #fff;
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.55rem 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
}

.announcement-bar a {
  color: #fff;
  text-decoration: none;
  white-space: nowrap;
  opacity: 0.8;
  transition: opacity 0.2s;
}

.announcement-bar a:hover {
  opacity: 1;
}

/* Header */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 2.5rem;
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border-light);
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: -0.01em;
}

.logo-dots {
  flex-shrink: 0;
}

.main-nav {
  display: flex;
  gap: 2rem;
}

.main-nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 400;
  transition: color 0.2s;
}

.main-nav a:hover {
  color: var(--text);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-cta {
  display: inline-flex;
  align-items: center;
  background: #000;
  color: #fff;
  text-decoration: none;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  padding: 0.65rem 1.1rem;
  border: none;
  cursor: pointer;
  font-family: var(--font);
  transition: opacity 0.2s;
}

[data-theme="dark"] .btn-cta {
  background: #fff;
  color: #000;
}

.btn-cta:hover:not(:disabled) {
  opacity: 0.85;
}

.btn-cta:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.btn-cta.btn-sm {
  padding: 0.55rem 1rem;
}

.btn-secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-family: var(--font);
  font-size: 0.8rem;
  padding: 0.55rem 1rem;
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s;
}

.btn-secondary:hover:not(:disabled) {
  border-color: var(--text);
  color: var(--text);
}

.btn-secondary:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.theme-toggle {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0.4rem;
  display: flex;
  align-items: center;
  transition: color 0.2s;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--text);
}

/* Hero */
.hero {
  position: relative;
  padding: 3rem 2.5rem 0;
  min-height: calc(100vh - 120px);
  display: flex;
  flex-direction: column;
}

.hero-lines {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  color: var(--text);
  pointer-events: none;
  z-index: 0;
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 2rem;
  flex: 1;
  max-width: 1300px;
  margin: 0 auto;
  width: 100%;
  padding: 2rem 0 4rem;
}

.hero-badge {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.badge-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  background: var(--accent);
  color: #fff;
  border-radius: 4px;
  font-size: 0.7rem;
}

.badge-label {
  font-weight: 500;
  color: var(--text);
}

.hero h1 {
  font-size: clamp(3.5rem, 7vw, 5.5rem);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 2rem;
  color: var(--text);
}

.bracket {
  font-weight: 600;
}

.hero-body {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 480px;
  line-height: 1.7;
  font-weight: 400;
}

.underline {
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--text-tertiary);
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.wireframe-globe {
  width: 100%;
  max-width: 480px;
  color: var(--text);
}

.wireframe-globe .orbit {
  transform-origin: 250px 250px;
  animation: spin 30s linear infinite;
}

.wireframe-globe .orbit-2 {
  animation: spin 45s linear infinite reverse;
}

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

.hero-divider {
  border-top: 1px solid var(--border);
  margin-top: auto;
}

.section-tag {
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  padding: 1.25rem 2.5rem;
}

/* Sections */
.section {
  padding: 4rem 2.5rem 0;
  border-top: 1px solid var(--border-light);
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding-bottom: 4rem;
}

.section-title {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.section-lead {
  font-size: 0.95rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin-bottom: 3rem;
  line-height: 1.7;
}

/* Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}

.card {
  background: var(--bg);
  padding: 2rem 1.5rem;
  transition: background 0.2s;
}

.card:hover {
  background: var(--bg-alt);
}

.card-index {
  display: block;
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--text-tertiary);
  letter-spacing: 0.05em;
  margin-bottom: 1.25rem;
}

.card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.6rem;
  color: var(--text);
}

.card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Equation animation */
.equation-block {
  border: 1px solid var(--border);
  padding: 2.5rem 1.25rem 2rem;
  margin-bottom: 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.equation-flow {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: center;
  gap: 0.65rem 1rem;
  margin-bottom: 1.25rem;
  position: relative;
  z-index: 1;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  padding: 0.25rem 0;
}

.equation-flow::-webkit-scrollbar {
  display: none;
}

.eq-group {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem 0.65rem;
  flex-shrink: 0;
}

.eq-term {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  flex-shrink: 0;
  animation: eqBob 3s ease-in-out infinite;
}

.eq-co2 { animation-delay: 0s; }
.eq-h2o { animation-delay: 0.3s; }
.eq-light { animation-delay: 0.6s; }
.eq-glucose { animation-delay: 0.15s; }
.eq-o2 { animation-delay: 0.45s; }

@keyframes eqBob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

.eq-mini {
  width: 28px;
  height: auto;
  flex-shrink: 0;
}

.eq-formula {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  white-space: nowrap;
  line-height: 1;
}

.eq-formula sub {
  font-size: 0.65em;
  vertical-align: sub;
  font-weight: 600;
}

.eq-num {
  font-size: 1em;
  font-weight: 600;
  color: var(--text-secondary);
  margin-right: 0.1em;
}

.eq-light-label {
  font-style: italic;
  font-weight: 500;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.eq-op {
  font-size: 1.15rem;
  color: var(--text-tertiary);
  font-weight: 300;
  flex-shrink: 0;
  line-height: 1;
}

.eq-arrow {
  font-size: 1.5rem;
  color: var(--text);
  font-weight: 300;
  flex-shrink: 0;
  line-height: 1;
  padding: 0 0.15rem;
  animation: eqArrowPulse 2s ease-in-out infinite;
}

@keyframes eqArrowPulse {
  0%, 100% { opacity: 0.45; transform: translateX(0); }
  50% { opacity: 1; transform: translateX(3px); }
}

.eq-sun {
  animation: eqSunPulse 2s ease-in-out infinite;
}

@keyframes eqSunPulse {
  0%, 100% { filter: brightness(1); }
  50% { filter: brightness(1.25); }
}

.equation-block.in-view .eq-glucose .eq-mini {
  animation: eqGlucoseGlow 2s ease-in-out infinite;
}

@keyframes eqGlucoseGlow {
  0%, 100% { filter: drop-shadow(0 0 0 transparent); }
  50% { filter: drop-shadow(0 0 6px rgba(245, 200, 66, 0.55)); }
}

.eq-particle-track {
  position: absolute;
  left: 5%;
  right: 5%;
  top: 50%;
  height: 4px;
  pointer-events: none;
  z-index: 0;
}

.eq-dot {
  position: absolute;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  top: 0;
  opacity: 0;
  animation: eqDotFlow 3.5s linear infinite;
}

.eq-dot-1 { background: #f5c842; animation-delay: 0s; }
.eq-dot-2 { background: #4a9fd4; animation-delay: 1.1s; }
.eq-dot-3 { background: #ff8866; animation-delay: 2.2s; }

@keyframes eqDotFlow {
  0% { left: 0; opacity: 0; }
  10% { opacity: 0.9; }
  90% { opacity: 0.9; }
  100% { left: 100%; opacity: 0; }
}

@media (max-width: 600px) {
  .equation-flow {
    justify-content: flex-start;
    padding: 0.25rem 0.5rem;
  }

  .eq-formula {
    font-size: 0.95rem;
  }

  .eq-mini {
    width: 22px;
  }
}

.equation-note {
  font-size: 0.85rem;
  color: var(--text-secondary);
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.6;
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.stat {
  text-align: left;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.stat strong {
  display: block;
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.35rem;
  color: var(--text);
}

.stat span {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Process */
.process-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-bottom: 3rem;
}

.process-card {
  background: var(--bg);
  padding: 2rem;
}

.process-header {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
}

.process-num {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-tertiary);
  letter-spacing: 0.05em;
}

.process-header h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.process-loc {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.process-card ul {
  list-style: none;
  margin-bottom: 1.5rem;
}

.process-card li {
  font-size: 0.85rem;
  color: var(--text-secondary);
  padding: 0.35rem 0;
  padding-left: 1rem;
  position: relative;
  line-height: 1.5;
}

.process-card li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--text-tertiary);
}

.process-flow {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-light);
  letter-spacing: 0.02em;
}

.diagram-block {
  text-align: center;
  padding: 2rem;
  border: 1px solid var(--border);
}

.diagram-block h3 {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  letter-spacing: 0.02em;
}

.chloroplast-svg {
  max-width: 520px;
  width: 100%;
  color: var(--text);
  font-family: var(--font);
}

.chloroplast-svg .chl-label {
  paint-order: stroke fill;
  stroke: var(--bg);
  stroke-width: 5px;
  stroke-linejoin: round;
  stroke-linecap: round;
}

.chl-labels {
  pointer-events: none;
}

.chl-diagram-wrap {
  position: relative;
  display: inline-block;
  max-width: 520px;
  width: 100%;
}

.chl-interactive .chl-part {
  cursor: pointer;
  transition: opacity 0.2s;
}

.chl-interactive .chl-part:hover {
  opacity: 0.85;
}

.chl-interactive .chl-part:hover ellipse,
.chl-interactive .chl-part:hover path,
.chl-interactive .chl-part:hover circle {
  filter: brightness(1.1);
}

.chl-tooltip {
  position: absolute;
  z-index: 10;
  background: var(--text);
  color: var(--bg);
  padding: 0.65rem 0.9rem;
  border-radius: 6px;
  font-size: 0.75rem;
  line-height: 1.45;
  max-width: 220px;
  pointer-events: none;
  box-shadow: 0 4px 20px rgba(0,0,0,0.15);
  transform: translate(-50%, -100%) translateY(-8px);
}

.chl-tooltip strong {
  display: block;
  font-size: 0.8rem;
  margin-bottom: 0.2rem;
}

/* Simulator scene */
.sim-scene {
  position: relative;
  width: 100%;
  max-width: 320px;
  margin: 0 auto;
}

.sim-svg {
  width: 100%;
  height: auto;
  border: 1px solid var(--border-light);
  border-radius: 8px;
  overflow: hidden;
  background: #d8ebf7;
}

#sim-rain line {
  animation: rainFall 0.7s linear infinite;
}

#sim-rain line:nth-child(2) { animation-delay: 0.15s; }
#sim-rain line:nth-child(3) { animation-delay: 0.3s; }
#sim-rain line:nth-child(4) { animation-delay: 0.08s; }
#sim-rain line:nth-child(5) { animation-delay: 0.22s; }
#sim-rain line:nth-child(6) { animation-delay: 0.38s; }
#sim-rain line:nth-child(7) { animation-delay: 0.12s; }
#sim-rain line:nth-child(8) { animation-delay: 0.28s; }

.sim-sun {
  transition: r 0.4s, opacity 0.4s;
}

#sim-sun-rays line {
  transform-origin: 0 0;
  animation: sunRaySpin 8s linear infinite;
}

@keyframes sunRaySpin {
  to { transform: rotate(360deg); }
}

.sim-badge {
  position: absolute;
  top: 0.75rem;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.35rem 0.75rem;
  border-radius: 20px;
  white-space: nowrap;
}

.sim-badge.dead {
  background: #8B4513;
  color: #fff;
}

.sim-badge.prosper {
  background: #3d7a37;
  color: #fff;
  animation: badgePulse 1.5s ease-in-out infinite;
}

@keyframes badgePulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(61,122,55,0.4); }
  50% { box-shadow: 0 0 0 8px rgba(61,122,55,0); }
}

@keyframes rainFall {
  0% { transform: translateY(0); opacity: 0.8; }
  100% { transform: translateY(180px); opacity: 0; }
}

/* Quiz */
.quiz-wrap {
  max-width: 640px;
}

.simulator {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-bottom: 3rem;
}

.sim-controls,
.sim-output {
  background: var(--bg);
  padding: 2rem;
}

.sim-controls label {
  display: block;
  margin-bottom: 1.5rem;
}

.sim-controls label span {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 0.6rem;
  letter-spacing: 0.01em;
}

.sim-controls input[type="range"] {
  width: 100%;
  accent-color: var(--text);
  cursor: pointer;
  height: 2px;
}

.sim-output {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
}

.sim-visual {
  color: var(--text);
  transition: transform 0.4s, opacity 0.4s;
}

.sim-visual svg path {
  transition: stroke-opacity 0.4s;
}

.sim-meter {
  width: 100%;
  text-align: center;
}

.meter-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.meter-bar {
  height: 2px;
  background: var(--border);
  margin: 0.75rem 0;
  overflow: hidden;
}

.meter-fill {
  height: 100%;
  background: var(--text);
  width: 72%;
  transition: width 0.4s;
}

.meter-value {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text);
}

.sim-status {
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-align: center;
  line-height: 1.5;
}

.factor-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.factor-card h4 {
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--text);
}

.factor-card p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* Quiz */
.quiz {
  border: 1px solid var(--border);
  padding: 2.5rem;
}

.quiz-question {
  display: none;
}

.quiz-question.active {
  display: block;
}

.q-text {
  font-size: 1rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
  color: var(--text);
  line-height: 1.5;
}

.q-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.q-option {
  padding: 0.85rem 1.25rem;
  border: 1px solid var(--border);
  background: var(--bg);
  font-family: var(--font);
  font-size: 0.85rem;
  cursor: pointer;
  text-align: left;
  color: var(--text);
  transition: border-color 0.2s, background 0.2s;
}

.q-option:hover:not(:disabled) {
  border-color: var(--text);
}

.q-option.correct {
  border-color: var(--text);
  background: var(--bg-alt);
  font-weight: 500;
}

.q-option.wrong {
  border-color: #cc4444;
  color: #cc4444;
}

.q-option:disabled {
  cursor: default;
}

.quiz-feedback {
  margin-top: 1rem;
  padding: 0.75rem 0;
  font-size: 0.85rem;
  color: var(--text-secondary);
  border-top: 1px solid var(--border-light);
}

.quiz-feedback[hidden] {
  display: none !important;
}

.quiz-feedback.quiz-complete {
  margin-top: 0;
  padding: 1.25rem 0 0;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
  border-top: 1px solid var(--border);
}

.quiz-results {
  text-align: center;
  padding: 1.5rem 0 0.5rem;
  border-top: 1px solid var(--border);
}

.quiz-results[hidden] {
  display: none !important;
}

#quiz-questions[hidden] {
  display: none !important;
}

.quiz-results p {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 1rem;
  line-height: 1.6;
}

.quiz-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.quiz-progress {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  letter-spacing: 0.05em;
}

/* Footer */
.footer {
  border-top: 1px solid var(--border);
  padding: 3rem 2.5rem;
  margin-top: 2rem;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.logo-footer {
  font-size: 0.85rem;
}

.footer p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-align: right;
}

.footer-credit {
  max-width: 1100px;
  margin: 1.5rem auto 0;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

.footer-credit a {
  color: var(--text-secondary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.footer-credit a:hover {
  color: var(--text);
}

/* Responsive */
@media (max-width: 1024px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .factor-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .announcement-bar {
    font-size: 0.55rem;
    padding: 0.5rem 1rem;
    flex-direction: column;
    gap: 0.35rem;
    text-align: center;
  }

  .site-header {
    padding: 1rem 1.25rem;
  }

  .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg);
    padding: 1rem 1.25rem 1.5rem;
    gap: 0.75rem;
    border-bottom: 1px solid var(--border);
  }

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

  .header-actions .btn-cta {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .site-header {
    position: relative;
    flex-wrap: wrap;
  }

  .hero {
    padding: 1.5rem 1.25rem 0;
    min-height: auto;
  }

  .hero-inner {
    grid-template-columns: 1fr;
    padding: 1rem 0 2rem;
  }

  .hero-visual {
    order: -1;
  }

  .wireframe-globe {
    max-width: 280px;
  }

  .hero h1 {
    font-size: clamp(2.5rem, 10vw, 3.5rem);
  }

  .section {
    padding: 3rem 1.25rem 0;
  }

  .section-tag {
    padding: 1rem 1.25rem;
  }

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

  .stats-row {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .factor-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer p {
    text-align: center;
  }
}