:root {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-2: #eef4ff;
  --text: #0f172a;
  --muted: #475569;
  --line: #dbe4f0;
  --primary: #2457c5;
  --primary-dark: #123a91;
  --accent: #10b981;
  --shadow: 0 20px 60px rgba(15, 23, 42, 0.10);
  --radius-lg: 26px;
  --radius-md: 18px;
  --radius-sm: 12px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

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

a:hover {
  color: var(--primary-dark);
}

img {
  max-width: 100%;
  display: block;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: rgba(248, 250, 252, 0.86);
  border-bottom: 1px solid rgba(219, 228, 240, 0.8);
}

.navbar {
  max-width: 1180px;
  margin: 0 auto;
  padding: 16px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text);
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  min-width: 44px;
  height: 32px;
  padding: 0 9px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--primary), #6ea8ff);
  color: #fff;
  font-size: 0.78rem;
}

.nav-links {
  display: flex;
  gap: 18px;
  align-items: center;
  font-size: 0.92rem;
  font-weight: 600;
}

.nav-links a {
  color: var(--muted);
}

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

.container {
  width: min(1120px, calc(100% - 44px));
  margin: 0 auto;
}

.section-pad {
  padding: 84px 0;
}

.hero {
  position: relative;
  overflow: hidden;
  padding-top: 88px;
  background:
    radial-gradient(circle at 18% 16%, rgba(36, 87, 197, 0.18), transparent 32%),
    radial-gradient(circle at 82% 20%, rgba(16, 185, 129, 0.16), transparent 28%);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.8fr);
  gap: 42px;
  align-items: center;
}

.eyebrow,
.section-kicker {
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.78rem;
  font-weight: 800;
  margin: 0 0 14px;
}

h1,
h2,
h3 {
  line-height: 1.13;
  letter-spacing: -0.035em;
  margin: 0;
}

h1 {
  font-size: clamp(2.35rem, 5vw, 4.8rem);
  max-width: 920px;
}

h2 {
  font-size: clamp(2rem, 3.5vw, 3.2rem);
  margin-bottom: 18px;
}

h3 {
  font-size: 1.22rem;
  margin-bottom: 10px;
}

.lead {
  font-size: 1.12rem;
  color: var(--muted);
  max-width: 820px;
  margin: 24px 0 20px;
}

.authors {
  font-weight: 700;
  margin: 0 0 6px;
}

.affiliations {
  color: var(--muted);
  margin: 0 0 26px;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text);
  font-weight: 800;
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.06);
}

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

.btn.muted {
  color: var(--muted);
}

.hero-card,
.card,
.method-step,
.table-card,
.code-card,
.equation-box,
.figure-block {
  background: rgba(255, 255, 255, 0.86);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.hero-card {
  padding: 18px;
}

.stat-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 12px;
}

.stat-card {
  padding: 18px;
  border-radius: var(--radius-md);
  background: linear-gradient(180deg, #ffffff, #f4f7fb);
  border: 1px solid var(--line);
}

.stat-card.main {
  background: linear-gradient(135deg, var(--primary), #5a8dff);
  color: #fff;
}

.stat-value {
  display: block;
  font-size: clamp(1.6rem, 4vw, 2.8rem);
  font-weight: 900;
  letter-spacing: -0.05em;
}

.stat-label {
  display: block;
  color: inherit;
  opacity: 0.82;
  font-weight: 700;
  font-size: 0.86rem;
}

.figure-block {
  padding: 18px;
  overflow: hidden;
}

.figure-block img {
  width: 100%;
  border-radius: var(--radius-md);
  background: #fff;
}

.caption {
  margin: 12px 4px 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.in-section {
  margin: 28px 0;
}

.two-col {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 56px;
}

.body-text p,
.section-lead {
  color: var(--muted);
  font-size: 1.02rem;
}

.subtle {
  background: linear-gradient(180deg, #eef4ff 0%, #f8fafc 100%);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.cards {
  display: grid;
  gap: 18px;
  margin-top: 28px;
}

.cards.three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card {
  padding: 24px;
}

.card p {
  color: var(--muted);
  margin: 0;
}

.card-number,
.method-step span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  margin-bottom: 16px;
  background: var(--surface-2);
  color: var(--primary);
  font-weight: 900;
}

.card.emphasis {
  border-color: rgba(36, 87, 197, 0.34);
  background: linear-gradient(180deg, #ffffff, #edf4ff);
}

.method-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin: 28px 0;
}

.method-step {
  padding: 22px;
}

.method-step p {
  color: var(--muted);
  margin: 0;
}

.equation-box {
  padding: 22px;
  display: grid;
  gap: 10px;
}

.equation-box span {
  font-weight: 800;
}

.equation-box code,
.code-card pre {
  display: block;
  overflow-x: auto;
  padding: 16px;
  border-radius: var(--radius-sm);
  background: #0f172a;
  color: #e2e8f0;
  font-size: 0.92rem;
}

.dataset-grid,
.results-grid,
.citation-grid,
.footer-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

.table-card {
  padding: 22px;
  overflow-x: auto;
}

.table-card.large,
.table-card.wide {
  box-shadow: 0 12px 36px rgba(15, 23, 42, 0.08);
}

.table-card.wide {
  margin-top: 24px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.94rem;
}

th,
td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}

th {
  color: var(--muted);
  font-weight: 800;
  background: #f8fafc;
}

tr:last-child td,
tr:last-child th {
  border-bottom: 0;
}

.compact .card {
  padding: 20px;
}

.resource a {
  display: inline-block;
  margin-top: 14px;
  font-weight: 800;
  word-break: break-word;
}

.code-card {
  position: relative;
  padding: 20px;
}

.copy-btn {
  position: absolute;
  top: 30px;
  right: 30px;
  border: 0;
  border-radius: 999px;
  padding: 9px 14px;
  background: var(--accent);
  color: #fff;
  font-weight: 800;
  cursor: pointer;
}

.site-footer {
  padding: 32px 0;
  border-top: 1px solid var(--line);
  background: #fff;
  color: var(--muted);
}

.footer-grid {
  align-items: center;
}

.footer-grid a {
  justify-self: end;
  font-weight: 800;
}

@media (max-width: 920px) {
  .nav-links {
    display: none;
  }

  .hero-grid,
  .two-col,
  .dataset-grid,
  .results-grid,
  .citation-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .cards.three,
  .method-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid a {
    justify-self: start;
  }
}

@media (max-width: 620px) {
  .container {
    width: min(100% - 28px, 1120px);
  }

  .section-pad {
    padding: 58px 0;
  }

  .cards.three,
  .method-grid,
  .stat-row {
    grid-template-columns: 1fr;
  }

  .copy-btn {
    position: static;
    margin-bottom: 12px;
  }
}