:root {
  color-scheme: dark;
  --bg: #07111f;
  --panel: rgba(16, 34, 57, 0.88);
  --panel-strong: #102943;
  --line: rgba(125, 211, 252, 0.2);
  --text: #f8fafc;
  --muted: #a7bbd1;
  --cyan: #22d3ee;
  --blue: #60a5fa;
  --lime: #a3e635;
  --orange: #fb923c;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 8%, rgba(34, 211, 238, 0.2), transparent 28rem),
    radial-gradient(circle at 86% 18%, rgba(96, 165, 250, 0.16), transparent 30rem),
    var(--bg);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.7;
}

a { color: var(--cyan); }
a:hover { color: #fff; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: rgba(7, 17, 31, 0.86);
  backdrop-filter: blur(16px);
}

.nav,
.page-shell,
.footer-inner {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

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

.brand {
  color: #fff;
  font-size: 1.25rem;
  font-weight: 800;
  text-decoration: none;
}

.brand span { color: var(--cyan); }

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

.nav-links a {
  color: var(--muted);
  font-weight: 650;
  text-decoration: none;
}

.hero {
  padding: 88px 0 42px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--lime);
  font-size: 0.82rem;
  font-weight: 850;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(2.5rem, 6vw, 5.25rem);
  line-height: 1.03;
  letter-spacing: -0.055em;
}

.lede {
  max-width: 780px;
  margin: 26px 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.3rem);
}

.signal-bar {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin: 34px 0 0;
}

.signal {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(9, 24, 41, 0.72);
}

.signal strong {
  display: block;
  color: #fff;
}

.signal span {
  color: var(--muted);
  font-size: 0.92rem;
}

.content-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 28px;
  padding: 24px 0 84px;
}

.article,
.side-card {
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--panel);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.24);
}

.article {
  padding: clamp(24px, 5vw, 54px);
}

.article section + section {
  margin-top: 54px;
  padding-top: 42px;
  border-top: 1px solid var(--line);
}

h2 {
  margin: 0 0 16px;
  font-size: clamp(1.55rem, 3vw, 2.2rem);
  letter-spacing: -0.025em;
}

h3 { margin: 28px 0 8px; }

p { color: #d7e3ef; }

.checklist,
.related-list {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.checklist li {
  position: relative;
  margin: 12px 0;
  padding: 14px 16px 14px 44px;
  border-radius: 14px;
  background: rgba(96, 165, 250, 0.08);
}

.checklist li::before {
  position: absolute;
  left: 16px;
  color: var(--lime);
  content: "✓";
  font-weight: 900;
}

.note {
  margin: 28px 0;
  padding: 20px 22px;
  border-left: 4px solid var(--orange);
  border-radius: 8px 16px 16px 8px;
  background: rgba(251, 146, 60, 0.1);
}

.side-card {
  position: sticky;
  top: 96px;
  padding: 24px;
}

.side-card h2 {
  font-size: 1.1rem;
}

.related-list li + li { margin-top: 13px; }

.related-list a {
  display: block;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  color: #dff8ff;
  background: rgba(34, 211, 238, 0.06);
  text-decoration: none;
}

.cta {
  margin-top: 34px;
  padding: 28px;
  border-radius: 20px;
  color: #05111d;
  background: linear-gradient(135deg, var(--cyan), var(--lime));
}

.cta h2,
.cta p { color: #05111d; }

.cta a {
  display: inline-flex;
  margin-top: 8px;
  padding: 12px 18px;
  border-radius: 12px;
  color: #fff;
  background: #07111f;
  font-weight: 800;
  text-decoration: none;
}

footer {
  border-top: 1px solid var(--line);
  color: var(--muted);
}

.footer-inner {
  padding: 28px 0 42px;
}

@media (max-width: 820px) {
  .nav { align-items: flex-start; padding: 18px 0; }
  .nav-links { justify-content: flex-end; }
  .signal-bar,
  .content-layout { grid-template-columns: 1fr; }
  .side-card { position: static; }
  .hero { padding-top: 54px; }
}

@media (max-width: 520px) {
  .nav-links a:nth-child(2) { display: none; }
  .signal-bar { gap: 9px; }
  .signal { padding: 13px; }
  .signal span { font-size: 0.8rem; }
}