@font-face {
  font-family: "Suisse Intl";
  src: url("/assets/fonts/suisseintl-book.woff2") format("woff2");
  font-display: swap;
}

:root {
  color-scheme: dark;
  --ink: #f8fafc;
  --muted: #94a3b8;
  --quiet: #64748b;
  --navy: #020617;
  --navy-soft: #071022;
  --card: rgba(15, 23, 42, 0.72);
  --line: rgba(51, 65, 85, 0.72);
  --cyan: #22d3ee;
  --blue: #2563eb;
  --max: 80rem;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 70% 8%, rgba(37, 99, 235, 0.12), transparent 30rem),
    var(--navy);
  font-family: Inter, "Suisse Intl", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

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

.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgba(255,255,255,.05);
  background: rgba(2, 6, 23, .84);
  backdrop-filter: blur(16px);
}

.nav-shell,
.page-shell {
  width: min(var(--max), calc(100% - 3rem));
  margin-inline: auto;
}

.nav-shell {
  min-height: 4rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  font-size: 1.125rem;
  font-weight: 700;
}

.brand-mark {
  width: 2rem;
  height: 2rem;
  display: grid;
  place-items: center;
  border-radius: .55rem;
  background: linear-gradient(90deg, #22d3ee, #2563eb);
}

.brand-name {
  color: transparent;
  background: linear-gradient(90deg, #22d3ee, #2563eb);
  background-clip: text;
}

.nav-actions { display: flex; align-items: center; gap: .75rem; }
.nav-link { color: #cbd5e1; font-size: .9rem; }
.nav-link:hover { color: #fff; }

.button {
  min-height: 2.25rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .55rem 1rem;
  border-radius: .75rem;
  background: linear-gradient(90deg, #22d3ee, #2563eb);
  color: #fff;
  font-size: .875rem;
  font-weight: 600;
  transition: opacity .15s ease, transform .15s ease;
}

.button:hover { opacity: .9; transform: translateY(-1px); }
.button.secondary { background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.1); }

.hub-hero,
.article-hero { padding: clamp(5rem, 10vw, 8.5rem) 0 4rem; }

.eyebrow {
  margin: 0 0 1rem;
  color: var(--cyan);
  text-transform: uppercase;
  letter-spacing: .12em;
  font-size: .72rem;
  font-weight: 700;
}

.hub-hero h1,
.article-hero h1 {
  max-width: 62rem;
  margin: 0;
  color: #fff;
  letter-spacing: -.045em;
  font-size: clamp(2.6rem, 7vw, 5.3rem);
  line-height: .98;
}

.hub-hero h1 span,
.article-hero h1 span {
  color: transparent;
  background: linear-gradient(90deg, #22d3ee, #3b82f6);
  background-clip: text;
}

.hero-copy {
  max-width: 48rem;
  margin: 1.5rem 0 0;
  color: #94a3b8;
  font-size: clamp(1rem, 2vw, 1.2rem);
  line-height: 1.7;
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: .65rem 1.25rem;
  margin-top: 1.5rem;
  color: #64748b;
  font-size: .82rem;
}

.meta-row a { color: #cbd5e1; }

.topic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  padding: 0 0 6rem;
}

.topic-card,
.related-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 1.25rem;
  background: var(--card);
  box-shadow: 0 26px 70px rgba(2, 6, 23, .32);
  transition: border-color .2s ease, transform .2s ease;
}

.topic-card:hover,
.related-card:hover { border-color: rgba(34, 211, 238, .45); transform: translateY(-2px); }

.topic-card { min-height: 19rem; padding: clamp(1.5rem, 4vw, 2.5rem); }
.topic-card:first-child { grid-column: 1 / -1; min-height: 22rem; }

.card-number {
  color: rgba(34, 211, 238, .55);
  font-family: ui-monospace, monospace;
  font-size: .78rem;
}

.topic-card h2,
.related-card h3 {
  margin: 2.8rem 0 1rem;
  color: #fff;
  letter-spacing: -.03em;
  font-size: clamp(1.55rem, 3vw, 2.25rem);
  line-height: 1.08;
}

.topic-card:first-child h2 { max-width: 47rem; font-size: clamp(2rem, 4.5vw, 3.5rem); }
.topic-card p,
.related-card p { margin: 0; color: var(--muted); line-height: 1.65; }
.read-link { display: inline-block; margin-top: 1.75rem; color: var(--cyan); font-size: .88rem; font-weight: 650; }

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 18rem;
  gap: 4rem;
  align-items: start;
  padding-bottom: 6rem;
}

.article-body { max-width: 49rem; }
.article-body .answer {
  margin: 0 0 2.5rem;
  padding: 1.4rem 1.5rem;
  border: 1px solid rgba(34, 211, 238, .28);
  border-radius: 1rem;
  background: rgba(8, 47, 73, .22);
  color: #dbeafe;
  font-size: 1.04rem;
  line-height: 1.7;
}

.article-body h2 {
  margin: 3.5rem 0 1rem;
  color: #fff;
  letter-spacing: -.03em;
  font-size: clamp(1.65rem, 3vw, 2.35rem);
  line-height: 1.15;
}

.article-body h3 { margin: 2.2rem 0 .75rem; color: #f8fafc; font-size: 1.18rem; }
.article-body p,
.article-body li { color: #cbd5e1; font-size: 1.03rem; line-height: 1.78; }
.article-body p { margin: 0 0 1.25rem; }
.article-body ul,
.article-body ol { margin: 1rem 0 1.5rem; padding-left: 1.25rem; }
.article-body li { margin: .65rem 0; }
.article-body a { color: #67e8f9; text-decoration: underline; text-underline-offset: .2em; }

.callout {
  margin: 2rem 0;
  padding: 1.35rem 1.5rem;
  border-left: 3px solid var(--cyan);
  background: rgba(15, 23, 42, .78);
  color: #e2e8f0;
  line-height: 1.7;
}

.table-wrap { margin: 1.5rem 0 2rem; overflow-x: auto; border: 1px solid var(--line); border-radius: 1rem; }
table { width: 100%; border-collapse: collapse; min-width: 36rem; background: rgba(15,23,42,.52); }
th, td { padding: 1rem; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { color: #fff; font-size: .82rem; text-transform: uppercase; letter-spacing: .06em; }
td { color: #cbd5e1; line-height: 1.55; }
tr:last-child td { border-bottom: 0; }

.toc {
  position: sticky;
  top: 6rem;
  padding: 1.2rem;
  border: 1px solid var(--line);
  border-radius: 1rem;
  background: rgba(15, 23, 42, .58);
}
.toc-title { margin: 0 0 .75rem; color: #64748b; text-transform: uppercase; letter-spacing: .1em; font-size: .7rem; font-weight: 700; }
.toc a { display: block; padding: .45rem 0; color: #94a3b8; font-size: .84rem; line-height: 1.35; }
.toc a:hover { color: #fff; }

.faq { margin-top: 3rem; }
.faq details { border-top: 1px solid var(--line); }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; padding: 1.1rem 0; color: #fff; font-weight: 600; }
.faq details p { padding: 0 0 1rem; color: #94a3b8; }

.sources { margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--line); }
.sources h2 { margin-top: 0; font-size: 1.2rem; }
.sources li { font-size: .88rem; color: #94a3b8; }

.cta {
  margin: 3.5rem 0 0;
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border: 1px solid rgba(59,130,246,.32);
  border-radius: 1.25rem;
  background: linear-gradient(135deg, rgba(8,47,73,.62), rgba(30,58,138,.55));
}
.cta h2 { margin: 0 0 .8rem; }
.cta p { max-width: 38rem; }
.cta .button { margin-top: .5rem; text-decoration: none; }

.related { padding: 5rem 0; border-top: 1px solid rgba(255,255,255,.05); background: #030817; }
.related-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 1rem; }
.related-card { padding: 1.4rem; }
.related-card h3 { margin: 1.5rem 0 .65rem; font-size: 1.2rem; }
.related-card p { font-size: .9rem; }

.site-footer { padding: 3rem 0; border-top: 1px solid rgba(255,255,255,.05); background: #020617; }
.footer-row { display: flex; justify-content: space-between; align-items: center; gap: 2rem; }
.footer-links { display: flex; flex-wrap: wrap; gap: 1.5rem; color: #94a3b8; font-size: .82rem; }
.copyright { margin-top: 1.5rem; color: #475569; font-size: .75rem; }

@media (max-width: 900px) {
  .article-layout { grid-template-columns: 1fr; }
  .toc { position: static; order: -1; }
  .related-grid { grid-template-columns: 1fr; }
}

@media (max-width: 680px) {
  .nav-shell, .page-shell { width: min(100% - 1.5rem, var(--max)); }
  .nav-link { display: none; }
  .hub-hero, .article-hero { padding-top: 4.5rem; }
  .topic-grid { grid-template-columns: 1fr; }
  .topic-card:first-child { grid-column: auto; }
  .footer-row { align-items: flex-start; flex-direction: column; }
  .article-body p, .article-body li { font-size: 1rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
}