:root {
  --bg: #f7f8f5;
  --panel: #ffffff;
  --text: #17211b;
  --muted: #5c685f;
  --line: #dbe1da;
  --accent: #19664a;
  --accent-dark: #104934;
  --warn: #fff3d6;
  --warn-line: #e5c263;
  --shadow: 0 18px 45px rgba(23, 33, 27, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

a {
  color: var(--accent);
}

.site-header {
  position: sticky;
  top: 36px;
  z-index: 10;
  background: rgba(247, 248, 245, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.medical-banner {
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 8px 20px;
  background: #2f2413;
  color: #fff8e8;
  text-align: center;
  font-size: 0.92rem;
}

.nav {
  max-width: 1160px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand {
  font-weight: 800;
  color: var(--text);
  text-decoration: none;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 0.95rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--muted);
}

main {
  max-width: 1160px;
  margin: 0 auto;
  padding: 32px 20px 56px;
}

.hero {
  min-height: 520px;
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(280px, 0.75fr);
  gap: 28px;
  align-items: center;
  padding: 54px 0 36px;
}

.hero h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 5rem);
  line-height: 0.96;
  letter-spacing: 0;
}

.lede {
  max-width: 690px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 1.17rem;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero-actions,
.converter-card,
.age-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-actions {
  margin-top: 28px;
}

.button,
button {
  border: 0;
  border-radius: 8px;
  padding: 12px 16px;
  font: inherit;
  font-weight: 750;
  text-decoration: none;
  cursor: pointer;
}

.primary {
  background: var(--accent);
  color: #fff;
}

.primary:hover {
  background: var(--accent-dark);
}

.secondary,
.tab {
  background: #e7eee8;
  color: var(--text);
}

.safety-box,
.converter-card,
.results-card,
.content-grid article,
.age-panel,
.checklist,
.sources,
.tracker-copy {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.safety-box {
  padding: 22px;
  box-shadow: var(--shadow);
}

.safety-box p {
  margin: 8px 0 0;
  color: var(--muted);
}

.safety-box a {
  display: inline-block;
  margin-top: 12px;
  font-weight: 800;
}

.tool-section,
.age-section,
.tracker-section,
.sources {
  margin-top: 34px;
  padding: 28px;
}

.tool-section,
.age-section,
.tracker-section {
  border-top: 1px solid var(--line);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 22px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(1.8rem, 3vw, 3rem);
  line-height: 1.05;
}

.section-heading p:not(.eyebrow) {
  margin: 12px 0 0;
  color: var(--muted);
}

.wide {
  grid-column: 1 / -1;
}

.converter-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.8fr);
  gap: 18px;
}

.converter-card {
  padding: 20px;
  align-items: end;
}

label {
  width: 100%;
  font-weight: 750;
}

input,
select {
  min-height: 46px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  font: inherit;
  background: #fff;
}

.converter-card input,
.converter-card select {
  flex: 1 1 180px;
}

.results-card {
  padding: 20px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.results-card div {
  padding: 14px;
  border-radius: 8px;
  background: #f3f6f1;
}

.results-card span {
  display: block;
  color: var(--muted);
  font-size: 0.82rem;
}

.results-card strong {
  display: block;
  margin-top: 4px;
  font-size: 1.5rem;
}

.fine-print {
  color: var(--muted);
  font-size: 0.92rem;
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 40px;
}

.content-grid article {
  padding: 20px;
}

.content-grid h3,
.checklist h3 {
  margin: 0 0 8px;
}

.content-grid p,
.checklist li,
.sources li {
  color: var(--muted);
}

.tab.active {
  background: var(--accent);
  color: #fff;
}

.age-panel {
  margin-top: 16px;
  padding: 22px;
  min-height: 220px;
}

.age-panel h3 {
  margin-top: 0;
}

.age-panel ul,
.checklist ul,
.sources ul {
  padding-left: 20px;
}

.tracker-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.9fr);
  gap: 18px;
}

.tracker-copy,
.checklist {
  padding: 24px;
}

.sources {
  background: var(--warn);
  border-color: var(--warn-line);
}

.text-page {
  max-width: 850px;
  margin: 46px auto;
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.text-page h1 {
  margin: 0 0 18px;
  font-size: clamp(2.1rem, 5vw, 4rem);
  line-height: 1;
}

.text-page h2 {
  margin-top: 28px;
}

.evidence-key {
  display: grid;
  gap: 10px;
  margin: 24px 0;
  padding: 16px;
  border: 1px solid var(--warn-line);
  border-radius: 8px;
  background: var(--warn);
}

.table-wrap {
  overflow-x: auto;
  margin: 24px 0;
}

table {
  width: 100%;
  min-width: 980px;
  border-collapse: collapse;
  background: #fff;
}

th,
td {
  padding: 13px;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  background: #edf2ec;
}

footer {
  border-top: 1px solid var(--line);
  padding: 24px 20px 44px;
  color: var(--muted);
  text-align: center;
}

@media (max-width: 820px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-header {
    top: 54px;
  }

  .hero,
  .converter-grid,
  .tracker-section,
  .content-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 34px;
  }

  .results-card {
    grid-template-columns: 1fr;
  }
}