:root {
  --bg: #f4f6f9;
  --bg-elevated: #ffffff;
  --text: #141922;
  --text-secondary: #3d4554;
  --muted: #5e6678;
  --border: #e1e6ee;
  --border-strong: #c5cdd9;
  --accent: #154a86;
  --accent-hover: #0f3a6a;
  --accent-soft: #e8f0fa;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(20, 25, 34, 0.06), 0 4px 20px rgba(20, 25, 34, 0.04);
  --max: 44rem;
  --header-max: 72rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-secondary);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0.75rem;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: #fff;
  z-index: 100;
  font-weight: 600;
  border-radius: 6px;
}

.skip-link:focus {
  left: 0.75rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.site-header__inner {
  max-width: var(--header-max);
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.65rem 1rem;
}

.site-header__brand {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  min-width: 0;
}

.logo {
  display: inline-flex;
  flex-direction: column;
  gap: 0.1rem;
  text-decoration: none;
  color: var(--text);
}

.logo__title {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.logo__tag {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.logo:hover .logo__title,
.logo:focus .logo__title {
  color: var(--accent);
}

.nav-toggle {
  display: none;
  padding: 0.45rem 0.85rem;
  font: inherit;
  font-weight: 600;
  color: var(--text);
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  cursor: pointer;
}

.site-nav {
  width: 100%;
  padding: 0;
}

.site-nav__bar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  width: 100%;
}

.site-nav__primary,
.site-nav__engines {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
}

.site-nav__primary {
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.85rem;
}

.site-nav__primary li,
.site-nav__engines li {
  margin: 0;
}

.site-nav__primary a {
  display: inline-block;
  padding: 0.5rem 0.65rem;
  border-radius: 8px;
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.92rem;
}

.site-nav__primary a:hover,
.site-nav__primary a:focus {
  background: var(--accent-soft);
  color: var(--accent);
}

.site-nav__engines-panel {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.site-nav__eyebrow {
  margin: 0;
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.site-nav__engines {
  gap: 0.35rem;
}

.site-nav__engines a {
  display: inline-block;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--text-secondary);
  background: var(--bg);
  border: 1px solid var(--border);
}

.site-nav__engines a:hover,
.site-nav__engines a:focus {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

.main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

.main h1 {
  font-size: clamp(1.75rem, 4vw, 2.15rem);
  line-height: 1.2;
  margin: 0 0 1rem;
  color: var(--text);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.main h2 {
  font-size: 1.15rem;
  margin: 2.25rem 0 0.65rem;
  color: var(--text);
  font-weight: 700;
  letter-spacing: -0.01em;
}

.main h3 {
  font-size: 1rem;
  margin: 1.5rem 0 0.4rem;
  color: var(--text);
  font-weight: 600;
}

.main p,
.main li {
  color: var(--text-secondary);
}

.main a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.main a:hover,
.main a:focus {
  color: var(--accent-hover);
}

.main .btn-primary,
.main .btn-primary:link,
.main .btn-primary:visited {
  color: #fff;
  text-decoration: none;
}

.main .btn-primary:hover,
.main .btn-primary:focus {
  color: #fff;
  text-decoration: none;
}

.lede {
  font-size: 1.08rem;
  line-height: 1.65;
  color: var(--text-secondary);
  margin: 0 0 1.5rem;
}

.metrics {
  margin: 2rem 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.75rem;
}

@media (min-width: 36rem) {
  .metrics {
    grid-template-columns: 1fr 1fr;
  }
}

.metrics li {
  margin: 0;
  padding: 1rem 1.1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.metrics strong {
  display: block;
  color: var(--text);
  font-size: 0.95rem;
  margin-bottom: 0.35rem;
}

.metrics span {
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.45;
}

.panel {
  margin: 1.75rem 0;
  padding: 1.25rem 1.35rem;
  background: var(--accent-soft);
  border: 1px solid #c9dcee;
  border-radius: var(--radius);
}

.panel h2 {
  margin-top: 0;
  font-size: 1.05rem;
}

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

.link-grid {
  display: grid;
  gap: 0.65rem;
  margin: 1.25rem 0 0;
  padding: 0;
  list-style: none;
}

.link-grid a {
  display: block;
  padding: 0.85rem 1.1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  font-weight: 600;
  box-shadow: var(--shadow);
}

.link-grid a:hover,
.link-grid a:focus {
  border-color: var(--accent);
  color: var(--accent);
}

.glossary dl {
  margin: 0;
}

.glossary dt {
  font-weight: 700;
  color: var(--text);
  margin-top: 1.35rem;
}

.glossary dt:first-child {
  margin-top: 0;
}

.glossary dd {
  margin: 0.35rem 0 0;
  color: var(--text-secondary);
}

.cta-block {
  margin-top: 2.75rem;
  padding: 1.75rem 1.5rem;
  text-align: center;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 2px);
  box-shadow: var(--shadow);
}

.cta-block__title {
  margin: 0 0 0.5rem;
  font-size: 1.2rem;
  color: var(--text);
}

.cta-block__lede {
  margin: 0 0 1.25rem;
  font-size: 0.95rem;
  color: var(--muted);
  max-width: 28rem;
  margin-left: auto;
  margin-right: auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font: inherit;
  font-weight: 700;
  font-size: 1rem;
  border-radius: 8px;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 2px 8px rgba(21, 74, 134, 0.25);
}

.btn-primary:hover,
.btn-primary:focus {
  background: var(--accent-hover);
  color: #fff;
  transform: translateY(-1px);
}

.meta {
  font-size: 0.85rem;
  color: var(--muted);
}

.site-footer {
  margin-top: 0;
  padding: 2.5rem 1.25rem;
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
}

.site-footer__inner {
  max-width: var(--header-max);
  margin: 0 auto;
}

.site-footer__tagline {
  margin: 0 0 1.25rem;
  font-size: 0.9rem;
  color: var(--muted);
  max-width: 36rem;
  line-height: 1.5;
}

.site-footer__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.75rem 2.5rem;
}

.site-footer__nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-footer__nav li {
  margin: 0.3rem 0;
}

.site-footer__nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
}

.site-footer__nav a:hover,
.site-footer__nav a:focus {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

@media (max-width: 52rem) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    display: none;
    padding-top: 1rem;
    margin-top: 0.35rem;
    border-top: 1px solid var(--border);
  }

  .site-nav.is-open {
    display: block;
  }

  .site-nav__primary {
    flex-direction: column;
    border-bottom: none;
    padding-bottom: 0;
    gap: 0;
  }

  .site-nav__primary li {
    border-bottom: 1px solid var(--border);
  }

  .site-nav__primary li:last-child {
    border-bottom: none;
  }

  .site-nav__primary a {
    display: block;
    padding: 0.75rem 0.35rem;
    border-radius: 0;
  }

  .site-nav__engines-panel {
    padding: 0.85rem 1rem;
    background: var(--bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
  }
}

@media (min-width: 52.01rem) {
  .site-header__inner {
    flex-wrap: nowrap;
    align-items: center;
  }

  .site-header__brand {
    width: auto;
    flex: 0 0 auto;
  }

  .site-nav {
    display: block !important;
    width: auto;
    flex: 1 1 auto;
    min-width: 0;
    margin-top: 0;
    padding-top: 0;
    border-top: none;
  }

  .site-nav__bar {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    justify-content: flex-end;
    gap: 0.75rem 1.25rem;
  }

  .site-nav__primary {
    border-bottom: none;
    padding-bottom: 0;
    justify-content: flex-end;
  }

  .site-nav__engines-panel {
    flex-direction: row;
    align-items: center;
    gap: 0.6rem;
    padding: 0.35rem 0.55rem 0.35rem 0.85rem;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.75);
  }

  .site-nav__eyebrow {
    white-space: nowrap;
    padding-right: 0.15rem;
  }
}

.page-figure {
  margin: 0 0 1.75rem;
  padding: 0;
  border-radius: calc(var(--radius) + 2px);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  background: var(--bg-elevated);
}

.page-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 880 / 320;
}