:root {
  --c-primary: #1a6b5c;
  --c-primary-lt: #e8f5f0;
  --c-primary-dk: #085041;
  --c-text: #1a1a1a;
  --c-muted: #555;
  --c-bg: #fff;
  --c-surface: #f7f7f5;
  --c-border: #e0e0dc;
  --c-warn: #e67e22;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --c-text: #e0e0e0;
    --c-muted: #aaa;
    --c-bg: #121212;
    --c-surface: #1e1e1e;
    --c-border: #333;
    --c-primary-lt: #1a3a34;
  }
}

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

body {
  font-family: var(--font);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.7;
}

.container {
  max-width: 860px;
  margin: auto;
  padding: 0 1.2rem;
}

.site-header {
  position: sticky;
  top: 0;
  background: var(--c-bg);
  border-bottom: 1px solid var(--c-border);
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  z-index: 100;
}

.site-header .logo {
  font-size: 18px;
  font-weight: 700;
  color: var(--c-primary);
  text-decoration: none;
}

.site-nav a {
  font-size: 14px;
  color: var(--c-muted);
  text-decoration: none;
  margin-left: 20px;
}

.site-nav a:hover {
  color: var(--c-primary);
}

.hero {
  padding: 3rem 0 2rem;
  text-align: center;
}

.hero h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--c-primary-dk);
  margin-bottom: 0.75rem;
}

.hero p {
  font-size: 1.05rem;
  color: var(--c-muted);
  max-width: 560px;
  margin: auto;
}

.system-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin: 2rem 0;
}

@media (min-width: 600px) {
  .system-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .system-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.system-card {
  border: 1px solid var(--c-border);
  border-radius: 10px;
  padding: 1.2rem;
  text-decoration: none;
  color: var(--c-text);
  display: block;
  background: var(--c-bg);
}

.system-card:hover {
  border-color: var(--c-primary);
  background: var(--c-primary-lt);
}

.system-card h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--c-primary-dk);
  margin-bottom: 4px;
}

.system-card p {
  font-size: 13px;
  color: var(--c-muted);
  margin: 0;
}

.section-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--c-primary-dk);
  margin: 2rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--c-primary-lt);
}

.breadcrumb {
  font-size: 13px;
  color: var(--c-muted);
  margin: 1rem 0;
  display: flex;
  gap: 6px;
  align-items: center;
}

.breadcrumb a {
  color: var(--c-primary);
  text-decoration: none;
}

.breadcrumb span {
  color: var(--c-muted);
}

.summary-card {
  border: 1px solid var(--c-border);
  border-radius: 10px;
  padding: 1.4rem;
  margin: 1.5rem 0;
  background: var(--c-surface);
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 768px) {
  .summary-card {
    grid-template-columns: 1fr 1fr;
  }
}

.summary-card .label {
  font-size: 12px;
  color: var(--c-muted);
  text-transform: uppercase;
  letter-spacing: .05em;
  margin-bottom: 2px;
}

.summary-card .value {
  font-size: 15px;
  font-weight: 600;
  color: var(--c-text);
}

.icd-badge {
  display: inline-block;
  background: var(--c-primary-lt);
  color: var(--c-primary-dk);
  font-size: 12px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
  font-family: monospace;
}

.severity-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
}

.severity-badge.mild {
  background: #e8f5e9;
  color: #2e7d32;
}

.severity-badge.moderate {
  background: #fff8e1;
  color: #f57f17;
}

.severity-badge.severe {
  background: #fce4ec;
  color: #c62828;
}

.last-reviewed {
  font-size: 11px;
  color: #999;
  margin: 4px 0;
}

.page-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin: 1.5rem 0;
  align-items: start;
}

@media (min-width: 768px) {
  .page-layout {
    grid-template-columns: 220px 1fr;
  }
}

.toc {
  position: sticky;
  top: 64px;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 10px;
  padding: 1rem;
}

.toc h4 {
  font-size: 13px;
  font-weight: 600;
  color: var(--c-muted);
  text-transform: uppercase;
  letter-spacing: .05em;
  margin-bottom: 0.75rem;
}

.toc a {
  display: block;
  font-size: 13px;
  color: var(--c-muted);
  text-decoration: none;
  padding: 4px 0;
  border-left: 2px solid transparent;
  padding-left: 8px;
  margin-bottom: 2px;
}

.toc a:hover {
  color: var(--c-primary);
  border-left-color: var(--c-primary);
}

article h2 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--c-primary-dk);
  margin: 2rem 0 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--c-border);
  scroll-margin-top: 70px;
}

article p {
  margin-bottom: 1rem;
  color: var(--c-text);
}

article ul,
article ol {
  margin: 0.5rem 0 1rem 1.4rem;
  color: var(--c-text);
}

article li {
  margin-bottom: 0.3rem;
}

article table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 14px;
}

article table th {
  background: var(--c-surface);
  padding: 8px 12px;
  text-align: left;
  font-weight: 600;
  border: 1px solid var(--c-border);
}

article table td {
  padding: 8px 12px;
  border: 1px solid var(--c-border);
}

article table tr:nth-child(even) {
  background: var(--c-surface);
}

.calc-link-box {
  border: 1px solid var(--c-primary);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  background: var(--c-primary-lt);
  margin: 1.5rem 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.calc-link-box span {
  font-size: 14px;
  color: var(--c-primary-dk);
  font-weight: 500;
}

.calc-link-box a {
  font-size: 13px;
  color: var(--c-primary-dk);
  font-weight: 700;
  text-decoration: none;
}

.related-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 1rem 0;
}

.related-links a {
  font-size: 13px;
  color: var(--c-primary-dk);
  background: var(--c-primary-lt);
  padding: 4px 12px;
  border-radius: 20px;
  text-decoration: none;
}

.related-links a:hover {
  background: var(--c-primary);
  color: white;
}

.ref-list {
  font-size: 13px;
  color: var(--c-muted);
  line-height: 1.6;
  padding-left: 1.4rem;
}

.ref-list li {
  margin-bottom: 0.5rem;
}

.disclaimer-box {
  border-left: 3px solid var(--c-warn);
  background: var(--c-surface);
  padding: 1rem 1.2rem;
  border-radius: 0 8px 8px 0;
  margin: 2rem 0;
  font-size: 13px;
  color: var(--c-muted);
  font-style: italic;
}

.site-footer {
  border-top: 1px solid var(--c-border);
  margin-top: 3rem;
  padding: 1.5rem 0;
  font-size: 13px;
  color: var(--c-muted);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}

.site-footer a {
  color: var(--c-muted);
  text-decoration: none;
  margin-left: 12px;
}

.site-footer a:hover {
  color: var(--c-primary);
}

.ad-unit {
  margin: 1.5rem auto;
  text-align: center;
  min-height: 90px;
  background: var(--c-surface);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ad-label {
  font-size: 11px;
  color: #bbb;
  display: block;
  margin-bottom: 4px;
  text-align: center;
}

.calc-pill {
  display: inline-block;
  border: 1px solid var(--c-primary);
  color: var(--c-primary-dk);
  background: var(--c-primary-lt);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  margin: 4px;
}

.calc-pill:hover {
  background: var(--c-primary);
  color: white;
}

@media print {
  .site-header,
  .site-nav,
  .ad-unit,
  .site-footer,
  .toc,
  .calc-link-box,
  .related-links,
  .breadcrumb {
    display: none !important;
  }

  body {
    background: white;
    color: black;
  }

  .container {
    max-width: 100%;
    padding: 0;
  }

  article {
    width: 100%;
  }

  .page-layout {
    display: block;
  }
}