:root {
  color-scheme: light;
  --bg: #f7faf8;
  --surface: #ffffff;
  --ink: #14202b;
  --muted: #5f6d7a;
  --line: #d8e2dc;
  --green: #247a54;
  --blue: #2d6fb2;
  --warm: #f0b44f;
  --soft-green: #e9f5ef;
  --soft-blue: #eaf2fb;
  --shadow: 0 24px 70px rgba(22, 43, 38, 0.13);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  background:
    linear-gradient(135deg, rgba(36, 122, 84, 0.08), transparent 30rem),
    linear-gradient(225deg, rgba(45, 111, 178, 0.08), transparent 28rem),
    var(--bg);
  color: var(--ink);
  margin: 0;
}

a {
  color: inherit;
}

.site-header {
  align-items: center;
  background: rgba(247, 250, 248, 0.92);
  border-bottom: 1px solid var(--line);
  display: flex;
  gap: 24px;
  justify-content: space-between;
  padding: 18px clamp(20px, 5vw, 76px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  align-items: center;
  color: var(--ink);
  display: inline-flex;
  font-size: 1rem;
  font-weight: 850;
  gap: 11px;
  text-decoration: none;
}

.brand-mark {
  align-items: center;
  background: var(--ink);
  border-radius: 12px;
  color: white;
  display: inline-flex;
  font-size: 0.8rem;
  height: 40px;
  justify-content: center;
  width: 40px;
}

.site-header nav,
.site-footer nav {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
}

.site-header a,
.site-footer a {
  font-size: 0.95rem;
  font-weight: 760;
  text-decoration-color: rgba(36, 122, 84, 0.28);
  text-underline-offset: 5px;
}

.hero {
  align-items: center;
  display: grid;
  gap: clamp(26px, 5vw, 64px);
  grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1.1fr);
  padding: clamp(34px, 5vw, 72px) clamp(20px, 5vw, 76px) 36px;
}

.hero-copy {
  max-width: 670px;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  letter-spacing: 0;
}

h1 {
  font-size: clamp(2.9rem, 5.4vw, 5.15rem);
  line-height: 1;
  margin-bottom: 20px;
}

h2 {
  font-size: clamp(2rem, 3.7vw, 3.7rem);
  line-height: 1.05;
  margin-bottom: 18px;
}

h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
}

p {
  color: var(--muted);
  font-size: 1.08rem;
  line-height: 1.75;
}

.hero-copy p {
  max-width: 590px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.button {
  align-items: center;
  border-radius: 12px;
  display: inline-flex;
  font-size: 1rem;
  font-weight: 850;
  justify-content: center;
  min-height: 52px;
  padding: 0 22px;
  text-decoration: none;
}

.button-primary {
  background: var(--green);
  box-shadow: 0 15px 34px rgba(36, 122, 84, 0.25);
  color: white;
}

.button-secondary {
  background: white;
  border: 1px solid var(--line);
  color: var(--ink);
}

.source-panel {
  background: rgba(255, 255, 255, 0.86);
  border: 1px solid var(--line);
  border-radius: 26px;
  box-shadow: var(--shadow);
  padding: clamp(20px, 2.6vw, 28px);
}

.panel-header {
  align-items: center;
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  margin-bottom: 14px;
  padding-bottom: 14px;
}

.panel-header strong {
  font-size: 1.3rem;
}

.panel-header span {
  background: var(--soft-blue);
  border-radius: 999px;
  color: var(--blue);
  font-weight: 800;
  padding: 8px 12px;
}

.source-panel dl {
  display: grid;
  gap: 10px;
  margin: 0;
}

.source-panel dl div {
  background: linear-gradient(135deg, #ffffff, #f6fbf9);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 13px 16px;
}

.source-panel dt {
  font-weight: 850;
  margin-bottom: 4px;
}

.source-panel dd {
  color: var(--muted);
  line-height: 1.55;
  margin: 0;
}

.method,
.sources,
.boundaries {
  padding: clamp(48px, 7vw, 92px) clamp(20px, 5vw, 76px);
}

.method {
  background: white;
  border-block: 1px solid var(--line);
}

.method > div:first-child,
.section-heading {
  max-width: 820px;
}

.proof-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(3, 1fr);
  margin-top: 34px;
}

.proof-grid article {
  border-left: 4px solid var(--green);
  padding: 8px 22px;
}

.proof-grid article:nth-child(2) {
  border-color: var(--blue);
}

.proof-grid article:nth-child(3) {
  border-color: var(--warm);
}

.proof-grid span {
  color: var(--green);
  display: inline-block;
  font-weight: 900;
  margin-bottom: 14px;
}

.proof-grid p {
  font-size: 0.99rem;
  margin-bottom: 0;
}

.source-table {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: 0 18px 54px rgba(22, 43, 38, 0.08);
  margin-top: 32px;
  overflow: hidden;
}

.source-row {
  display: grid;
  gap: 18px;
  grid-template-columns: 0.65fr 1.05fr 1fr;
  padding: 20px 22px;
}

.source-row + .source-row {
  border-top: 1px solid var(--line);
}

.source-row span {
  color: var(--muted);
  line-height: 1.55;
}

.source-row span:first-child {
  color: var(--ink);
  font-weight: 850;
}

.source-row a {
  color: var(--blue);
  font-weight: 750;
}

.source-row-head {
  background: var(--ink);
}

.source-row-head span,
.source-row-head span:first-child {
  color: white;
  font-size: 0.86rem;
  letter-spacing: 0;
  text-transform: uppercase;
}

.boundaries {
  align-items: center;
  background: linear-gradient(135deg, var(--soft-green), var(--soft-blue));
  display: grid;
  gap: clamp(24px, 5vw, 70px);
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 1.05fr);
}

.boundary-copy p:last-child {
  margin-bottom: 0;
}

.boundary-list {
  display: grid;
  gap: 12px;
}

.boundary-list p {
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid rgba(216, 226, 220, 0.88);
  border-radius: 14px;
  color: var(--ink);
  font-weight: 850;
  margin: 0;
  padding: 18px 20px;
}

.site-footer {
  align-items: center;
  background: #ffffff;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: space-between;
  padding: 28px clamp(20px, 5vw, 76px);
}

.site-footer strong {
  font-size: 1.2rem;
}

.site-footer p {
  font-size: 0.95rem;
  margin: 6px 0 0;
}

@media (max-width: 920px) {
  .hero,
  .boundaries {
    grid-template-columns: 1fr;
    min-height: 0;
  }

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

  .source-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  h1 {
    font-size: clamp(2.45rem, 13vw, 3.45rem);
  }

  .button {
    width: 100%;
  }

  .source-panel {
    border-radius: 20px;
  }
}