:root {
  --teal:        #00394a;
  --teal-mid:    #005a6e;
  --teal-light:  #cddbe4;
  --teal-xlight: #e8f3f7;
  --peach:       #f4c4bb;
  --peach-light: #fdf0ed;
  --peach-deep:  #e8a090;
  --cream:       #faf9f8;
  --warm-white:  #ffffff;
  --text:        #1a2e35;
  --text-mid:    #3d5a64;
  --text-soft:   #7a9aa5;
  --gold:        #c4793a;
  --font-serif:  'Cormorant Garamond', Georgia, serif;
  --font-sans:   'DM Sans', system-ui, sans-serif;
  --r:           8px;
  --r-lg:        16px;
  --shadow:      0 4px 24px rgba(0,57,74,0.10);
  --shadow-lg:   0 12px 48px rgba(0,57,74,0.16);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--warm-white);
  font-size: 16px; line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { font-family: var(--font-serif); font-weight: 400; line-height: 1.2; }
h1 { font-size: clamp(2.2rem, 4.5vw, 3.4rem); }
h2 { font-size: clamp(1.7rem, 3vw, 2.4rem); }
h3 { font-size: clamp(1.1rem, 2vw, 1.35rem); }

.eyebrow {
  font-family: var(--font-sans); font-size: 0.7rem; font-weight: 600;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--teal-mid); display: block; margin-bottom: 0.6rem;
}

.container { max-width: 1180px; margin: 0 auto; padding: 0 28px; }

/* HERO */
.sci-hero {
  background: linear-gradient(160deg, #002030 0%, var(--teal) 60%, #004a5e 100%);
  padding: 80px 0 72px; position: relative; overflow: hidden;
}
.sci-hero::after {
  content: ''; position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' xmlns='http://www.w3.org/2000/svg'%3E%3Ccircle cx='30' cy='30' r='0.8' fill='rgba(255,255,255,0.03)'/%3E%3C/svg%3E") repeat;
}
.sci-hero-inner { position: relative; z-index: 1; max-width: 780px; }
.sci-hero-inner .eyebrow { color: var(--peach); }
.sci-hero h1 { color: white; margin-bottom: 20px; }
.sci-hero h1 em { font-style: italic; color: var(--teal-light); }
.sci-hero p { color: rgba(255,255,255,0.75); font-size: 1.03rem; max-width: 620px; line-height: 1.72; margin-bottom: 36px; }

/* SECTION NAV */
.sci-section-nav { background: var(--teal-xlight); border-bottom: 1px solid rgba(0,57,74,0.1); position: sticky; top: 64px; z-index: 50; }
.sci-section-nav-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
}
.sci-section-link {
  padding: 12px 10px;
  font-size: 0.84rem;
  font-weight: 500;
  color: var(--text-mid);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
  white-space: nowrap;
}
.sci-section-link:not(:first-child)::before {
  content: '|';
  color: var(--text-soft);
  margin-right: 10px;
  font-weight: 400;
  pointer-events: none;
}
.sci-section-link:hover { color: var(--teal); border-bottom-color: var(--teal-light); }
.sci-section-link.active { color: var(--teal); border-bottom-color: var(--teal); }

.pillars-section,
.mechanisms-section,
.evidence-section,
.impact-section,
.guidelines-section {
  scroll-margin-top: calc(64px + 3.25rem); /* site nav + sci-section-nav */
}

/* PILLARS */
.pillars-section { padding: 80px 0; background: white; }
.pillars-header { text-align: center; margin-bottom: 56px; }
.pillars-header h2 { color: var(--teal); margin-bottom: 12px; }
.pillars-header p { color: var(--text-mid); max-width: 620px; margin: 0 auto; }
.pillars-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; }
.pillar {
  padding: 36px 28px;
  border-right: 1px solid rgba(0,57,74,0.10);
  text-align: center;
  transition: background 0.2s;
}
.pillar:last-child { border-right: none; }
.pillar:hover { background: var(--teal-xlight); }
.pillar-icon {
  width: 64px; height: 64px; border-radius: 50%;
  background: var(--teal-xlight);
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 20px;
  transition: background 0.2s;
}
.pillar:hover .pillar-icon { background: var(--teal); }
.pillar:hover .pillar-icon svg { stroke: white; }
.pillar h3 { color: var(--teal); font-size: 1.05rem; margin-bottom: 12px; }
.pillar p { font-size: 0.84rem; color: var(--text-mid); line-height: 1.65; }

/* MECHANISMS */
.mechanisms-section { padding: 80px 0; background: var(--teal-xlight); }
.mechanisms-header { margin-bottom: 48px; }
.mechanisms-header h2 { color: var(--teal); margin-bottom: 12px; }
.mechanisms-header p { color: var(--text-mid); max-width: 640px; }
.mechanisms-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.mechanism-card {
  background: white; border-radius: var(--r-lg); padding: 28px;
  box-shadow: 0 2px 12px rgba(0,57,74,0.07);
  border-top: 3px solid var(--teal-light);
  transition: transform 0.2s, box-shadow 0.2s;
}
.mechanism-card:hover { transform: translateY(-2px); box-shadow: var(--shadow); border-top-color: var(--teal); }
.mechanism-card-header { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
.mechanism-icon {
  width: 38px; height: 38px; border-radius: var(--r);
  background: var(--teal-xlight);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.mechanism-name-row { display: flex; align-items: center; justify-content: space-between; gap: 10px; flex: 1; }
.mechanism-name { font-family: var(--font-serif); font-size: 1.1rem; color: var(--teal); }
.mechanism-marker-count {
  font-family: var(--font-sans); font-size: 0.68rem; font-weight: 600;
  letter-spacing: 0.05em; text-transform: uppercase;
  color: var(--teal-mid); background: var(--teal-xlight);
  padding: 3px 10px; border-radius: 20px; white-space: nowrap; flex-shrink: 0;
}
.mechanism-body { font-size: 0.85rem; color: var(--text-mid); line-height: 1.72; min-height: 7.3rem; }
.mechanism-ref { font-size: 0.75rem; color: var(--text-soft); margin-top: 10px; font-style: italic; }
.mechanism-ref a { color: var(--teal-mid); text-decoration: underline; }
.mechanism-ref a:hover { color: var(--teal); }

/* EVIDENCE */
.evidence-section { padding: 80px 0; background: white; }
.evidence-header { margin-bottom: 48px; }
.evidence-header h2 { color: var(--teal); margin-bottom: 12px; }
.evidence-header p { color: var(--text-mid); max-width: 640px; }

.evidence-filter { display: flex; gap: 8px; margin-bottom: 36px; flex-wrap: wrap; }
.evidence-filter-btn {
  padding: 7px 16px; border-radius: 20px;
  border: 1.5px solid rgba(0,57,74,0.15);
  font-size: 0.8rem; font-weight: 500; color: var(--text-mid);
  cursor: pointer; background: white; font-family: var(--font-sans);
  transition: all 0.18s;
}
.evidence-filter-btn:hover { border-color: var(--teal); color: var(--teal); }
.evidence-filter-btn.active { background: var(--teal); border-color: var(--teal); color: white; }

.evidence-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.evidence-card {
  border: 1.5px solid rgba(0,57,74,0.10); border-radius: var(--r-lg);
  padding: 24px; transition: all 0.2s;
}
.evidence-card:hover { border-color: var(--teal-mid); box-shadow: var(--shadow); }
.evidence-card-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; margin-bottom: 12px; }
.evidence-source { font-weight: 600; font-size: 0.88rem; color: var(--teal); flex: 1; }
.evidence-source a { color: var(--teal); text-decoration: underline; }
.evidence-source a:hover { color: var(--teal-mid); }
.evidence-badge {
  font-size: 0.68rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase;
  padding: 4px 10px; border-radius: 20px; white-space: nowrap; flex-shrink: 0;
}
.badge-guideline  { background: rgba(0,57,74,0.08); color: var(--teal); }
.badge-review     { background: rgba(0,90,110,0.1);  color: var(--teal-mid); }
.badge-clinical   { background: rgba(196,121,58,0.1); color: var(--gold); }
.badge-basic      { background: rgba(205,219,228,0.6); color: var(--text-mid); }
.badge-rwe        { background: rgba(244,196,187,0.45); color: var(--peach-deep); }
.evidence-finding { font-size: 0.86rem; color: var(--text-mid); line-height: 1.65; margin-bottom: 12px; }
.evidence-year { font-size: 0.75rem; color: var(--text-soft); }
.evidence-year a { color: var(--text-soft); text-decoration: underline; }
.evidence-year a:hover { color: var(--teal-mid); }

/* IMPACT */
.impact-section { padding: 80px 0; background: var(--peach-light); }
.impact-header { margin-bottom: 48px; }
.impact-header h2 { color: var(--teal); margin-bottom: 12px; }
.impact-header p { color: var(--text-mid); max-width: 680px; font-size: 0.98rem; line-height: 1.75; }
.impact-stats-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px; margin-bottom: 16px;
}
.impact-stat-card {
  background: white; border-radius: var(--r-lg);
  padding: 32px 28px; box-shadow: 0 2px 12px rgba(0,57,74,0.07);
  text-align: center;
}
.impact-stat-value {
  font-family: var(--font-serif); font-size: 2.8rem;
  color: var(--teal); line-height: 1; margin-bottom: 8px;
}
.impact-stat-unit { font-size: 1.6rem; color: var(--peach-deep); }
.impact-stat-label { font-size: 0.85rem; color: var(--text-mid); line-height: 1.55; }
.impact-stat-ref { color: var(--teal-mid); text-decoration: none; font-size: 0.8rem; }
.impact-stat-ref:hover { text-decoration: underline; }
.impact-footnote {
  text-align: center; font-size: 0.78rem;
  color: var(--text-soft); margin-bottom: 20px; font-style: italic;
}
.impact-insights-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 20px; margin-bottom: 28px;
}
.impact-insight-card {
  background: white; border-radius: var(--r-lg);
  padding: 24px 26px; border-left: 4px solid var(--teal);
  box-shadow: 0 2px 10px rgba(0,57,74,0.06);
}
.impact-insight-title {
  font-weight: 700; font-size: 0.88rem;
  color: var(--teal); margin-bottom: 8px;
}
.impact-insight-body { font-size: 0.85rem; color: var(--text-mid); line-height: 1.65; }

/* GUIDELINES */
.guidelines-section { padding: 80px 0; background: white; }
.guidelines-header { margin-bottom: 48px; }
.guidelines-header h2 { color: var(--teal); margin-bottom: 12px; }
.guidelines-header p { color: var(--text-mid); max-width: 640px; }
.guidelines-timeline {
  display: flex; align-items: flex-start; gap: 0;
  max-width: 100%; position: relative; padding-top: 8px;
}
.guideline-item {
  flex: 1; min-width: 0;
  display: flex; flex-direction: column; align-items: center;
  text-align: center; padding: 0 16px; position: relative;
}
.guideline-item::before {
  content: ''; position: absolute; top: 25px; left: 0; right: 0;
  height: 2px; background: rgba(0,57,74,0.12); z-index: 0;
}
.guideline-item:first-child::before { left: 50%; }
.guideline-item:last-child::before { right: 50%; }
.guideline-year {
  font-family: var(--font-serif); font-size: 1.4rem; color: var(--teal);
  margin-bottom: 14px; position: relative; z-index: 1;
  background: white; padding: 0 4px;
}
.guideline-dot {
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--teal); border: 3px solid white;
  box-shadow: 0 0 0 2px var(--teal-light);
  margin-bottom: 20px; position: relative; z-index: 1;
}
.guideline-item-active .guideline-year { color: var(--peach-deep); }
.guideline-dot-active {
  background: var(--peach-deep);
  box-shadow: 0 0 0 2px var(--peach);
  animation: pulse-dot 2s ease infinite;
}
@keyframes pulse-dot {
  0%, 100% { box-shadow: 0 0 0 2px var(--peach); }
  50% { box-shadow: 0 0 0 5px var(--peach-light); }
}
.guideline-source { font-weight: 600; font-size: 0.84rem; color: var(--teal); margin-bottom: 8px; line-height: 1.35; }
.guideline-source a { color: var(--teal); text-decoration: underline; }
.guideline-source a:hover { color: var(--teal-mid); }
.guideline-text { font-size: 0.78rem; color: var(--text-mid); line-height: 1.6; }
.guideline-tag {
  display: inline-block; margin-top: 12px;
  background: rgba(0,57,74,0.08); color: var(--teal);
  font-size: 0.68rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase;
  padding: 3px 10px; border-radius: 12px; white-space: nowrap;
}
.guideline-item-active .guideline-tag { background: rgba(244,196,187,0.35); color: var(--peach-deep); }

/* SCI CTA */
.sci-cta {
  background: linear-gradient(135deg, var(--teal) 0%, #002535 100%);
  padding: 80px 0; text-align: center; position: relative; overflow: hidden;
}
.sci-cta::before { content: ''; position: absolute; inset: 0; background: url("data:image/svg+xml,%3Csvg width='40' height='40' xmlns='http://www.w3.org/2000/svg'%3E%3Ccircle cx='20' cy='20' r='0.8' fill='rgba(255,255,255,0.04)'/%3E%3C/svg%3E") repeat; }
.sci-cta-content { position: relative; z-index: 1; }
.sci-cta h2 { color: white; margin-bottom: 14px; }
.sci-cta p { color: rgba(255,255,255,0.72); max-width: 520px; margin: 0 auto 32px; font-size: 1rem; }
.sci-cta .eyebrow { color: var(--peach); }
.sci-cta-actions { display: flex; gap: 12px; justify-content: center; }

.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 26px; border-radius: var(--r); font-family: var(--font-sans); font-size: 0.88rem; font-weight: 500; text-decoration: none; cursor: pointer; border: none; transition: all 0.2s; }
.btn-teal { background: var(--teal); color: white; }
.btn-teal:hover { background: var(--teal-mid); }
.btn-white { background: white; color: var(--teal); }
.btn-white:hover { background: var(--teal-xlight); }
.btn-ghost-white { background: transparent; color: white; border: 1.5px solid rgba(255,255,255,0.5); }
.btn-ghost-white:hover { background: rgba(255,255,255,0.1); }

.fade-in { opacity: 0; transform: translateY(20px); transition: opacity 0.5s ease, transform 0.5s ease; }
.fade-in.visible { opacity: 1; transform: none; }

@media (max-width: 640px) {
  .sci-section-nav-inner {
    flex-wrap: wrap;
    justify-content: center;
    gap: 2px 0;
    padding: 7px 0;
  }
  .sci-section-link {
    padding: 6px 6px;
    font-size: 0.8rem;
    line-height: 1.35;
    white-space: normal;
    text-align: center;
  }
}

@media (max-width: 900px) {
  .pillars-grid { grid-template-columns: 1fr; }
  .pillar { border-right: none; border-bottom: 1px solid rgba(0,57,74,0.1); }
  .mechanisms-layout { grid-template-columns: 1fr; }
  .evidence-grid { grid-template-columns: 1fr; }
  .impact-stats-grid { grid-template-columns: 1fr; }
  .impact-insights-grid { grid-template-columns: 1fr; }
  .guidelines-timeline { flex-direction: column; align-items: stretch; gap: 0; }
  .guideline-item {
    flex-direction: row; align-items: flex-start; text-align: left;
    padding: 0 0 28px 0; gap: 20px;
  }
  .guideline-item::before {
    top: 0; bottom: 0; left: 6px; right: auto; width: 2px; height: auto;
  }
  .guideline-item:first-child::before { left: 6px; top: 25px; }
  .guideline-item:last-child::before { left: 6px; right: auto; bottom: 50%; }
  .guideline-year {
    order: 0; writing-mode: horizontal-tb; margin-bottom: 0;
    flex-shrink: 0; width: 56px; padding-top: 1px;
  }
  .guideline-dot { position: absolute; left: 0; top: 6px; margin-bottom: 0; }
  .guideline-content { text-align: left; }
  .nav-links { display: none; }
}