:root {
  --ink: #0a1722;
  --muted: #526272;
  --paper: #f7fbff;
  --panel: #ffffff;
  --line: #dbe7f0;
  --navy: #071827;
  --blue: #0a84ff;
  --cyan: #20c9ff;
  --violet: #8147ff;
  --orange: #d66f1f;
  --green: #168a5b;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  letter-spacing: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

.doc-header {
  background:
    linear-gradient(135deg, rgba(7, 24, 39, 0.96), rgba(11, 35, 56, 0.94)),
    linear-gradient(90deg, rgba(32, 201, 255, 0.2), rgba(129, 71, 255, 0.18));
  color: #eef8ff;
  padding: 28px clamp(20px, 5vw, 72px) 76px;
}

.doc-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.brand img {
  width: 48px;
  height: 34px;
  object-fit: contain;
}

.nav-links {
  display: flex;
  gap: 16px;
  color: #bdd2df;
  font-size: 13px;
}

.nav-links a {
  padding: 10px 12px;
  border: 1px solid rgba(238, 248, 255, 0.16);
  border-radius: 6px;
}

.doc-language-toggle {
  display: inline-grid;
  grid-template-columns: 1fr 1fr;
  overflow: hidden;
  border: 1px solid rgba(238, 248, 255, 0.18);
  border-radius: 6px;
}

.doc-language-toggle button {
  min-width: 40px;
  height: 37px;
  border: 0;
  border-right: 1px solid rgba(238, 248, 255, 0.14);
  color: #bdd2df;
  background: rgba(238, 248, 255, 0.04);
  font: inherit;
  font-size: 12px;
  font-weight: 850;
  letter-spacing: 0.08em;
  cursor: pointer;
}

.doc-language-toggle button:last-child {
  border-right: 0;
}

.doc-language-toggle button[aria-pressed="true"] {
  color: #071827;
  background: var(--cyan);
}

.doc-hero {
  width: min(1120px, 100%);
}

.doc-hero h1 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(42px, 6vw, 76px);
  line-height: 0.98;
  letter-spacing: 0;
}

.doc-hero p {
  max-width: 760px;
  margin: 24px 0 0;
  color: #bdd2df;
  font-size: 18px;
  line-height: 1.65;
}

.meta-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin: -42px auto 54px;
  width: min(1120px, calc(100% - 40px));
  border: 1px solid var(--line);
  background: var(--line);
  box-shadow: 0 24px 70px rgba(14, 30, 43, 0.12);
}

.meta-grid div {
  min-height: 118px;
  padding: 20px;
  background: var(--panel);
}

.meta-grid span {
  display: block;
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.meta-grid strong {
  display: block;
  margin-top: 12px;
  font-size: 16px;
  line-height: 1.35;
}

.doc-layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 56px;
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto 80px;
}

.toc {
  position: sticky;
  top: 24px;
  align-self: start;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.toc strong {
  display: block;
  margin-bottom: 14px;
  color: var(--navy);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.toc a {
  display: block;
  padding: 9px 0;
  color: var(--muted);
  font-size: 14px;
  border-top: 1px solid #eef3f7;
}

.doc-content {
  display: grid;
  gap: 22px;
}

.lang-panel {
  display: grid;
  gap: 22px;
}

.lang-panel[hidden] {
  display: none;
}

.section-card {
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.section-card h2 {
  margin: 0;
  color: var(--navy);
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.05;
  letter-spacing: 0;
}

.section-card h3 {
  margin: 30px 0 10px;
  color: var(--navy);
  font-size: 19px;
}

.section-card p,
.section-card li {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.68;
}

.section-card p {
  margin: 16px 0 0;
}

.section-card ul,
.section-card ol {
  margin: 18px 0 0;
  padding-left: 22px;
}

.callout {
  margin-top: 22px;
  padding: 18px 20px;
  border-left: 4px solid var(--cyan);
  background: #eef9ff;
  color: var(--ink);
  font-weight: 650;
  line-height: 1.55;
}

.warning {
  border-left-color: var(--orange);
  background: #fff4eb;
}

.two-col {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 22px;
}

.mini-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdff;
}

.mini-card strong {
  display: block;
  color: var(--navy);
}

.mini-card span {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  line-height: 1.5;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin-top: 22px;
  border: 1px solid var(--line);
  background: var(--line);
}

.stats div {
  padding: 20px;
  background: #fbfdff;
}

.stats strong {
  display: block;
  color: var(--blue);
  font-size: 34px;
  line-height: 1;
}

.stats span {
  display: block;
  margin-top: 10px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.4;
}

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 22px;
}

figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdff;
}

figure img {
  display: block;
  width: 100%;
  height: 230px;
  object-fit: cover;
  object-position: top center;
}

figcaption {
  padding: 14px 16px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.45;
}

.language-divider {
  display: flex;
  align-items: center;
  gap: 18px;
  color: var(--green);
  font-weight: 850;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.language-divider::before,
.language-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line);
}

.footer {
  padding: 28px clamp(20px, 5vw, 72px);
  background: var(--navy);
  color: #bdd2df;
  font-size: 12px;
}

@media print {
  .doc-header {
    padding-bottom: 40px;
  }

  .doc-nav,
  .toc {
    display: none;
  }

  .meta-grid,
  .doc-layout {
    width: 100%;
    margin-left: 0;
    margin-right: 0;
  }

  .doc-layout {
    display: block;
  }

  .section-card {
    break-inside: avoid;
    box-shadow: none;
  }
}

@media (max-width: 900px) {
  .meta-grid,
  .stats,
  .two-col,
  .evidence-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .doc-layout {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
  }
}

@media (max-width: 620px) {
  .doc-header {
    padding-top: 20px;
  }

  .doc-nav {
    align-items: flex-start;
    flex-direction: column;
    margin-bottom: 46px;
  }

  .nav-links {
    flex-wrap: wrap;
  }

  .doc-hero h1 {
    font-size: 40px;
  }

  .meta-grid,
  .stats,
  .two-col,
  .evidence-grid {
    grid-template-columns: 1fr;
  }
}