:root {
  --bg: #08111f;
  --bg-soft: #0e1a2d;
  --panel: rgba(255, 255, 255, 0.08);
  --panel-strong: rgba(255, 255, 255, 0.13);
  --text: #f4f7fb;
  --muted: #aab7cc;
  --brand: #7dd3fc;
  --brand-2: #c084fc;
  --accent: #34d399;
  --line: rgba(255, 255, 255, 0.14);
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.35);
  --radius-lg: 28px;
  --radius-md: 18px;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(125, 211, 252, 0.22), transparent 32rem),
    radial-gradient(circle at top right, rgba(192, 132, 252, 0.18), transparent 34rem),
    linear-gradient(180deg, #08111f 0%, #0a1220 45%, #101827 100%);
  line-height: 1.65;
}

a { color: inherit; text-decoration: none; }
p { color: var(--muted); }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: rgba(8, 17, 31, 0.78);
  border-bottom: 1px solid var(--line);
}

.nav {
  width: min(var(--max), calc(100% - 32px));
  margin: 0 auto;
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 14px;
  color: #06111f;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  box-shadow: 0 10px 35px rgba(125, 211, 252, 0.3);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 22px;
  color: var(--muted);
  font-size: 0.95rem;
}

.nav-menu a { transition: color 0.2s ease; }
.nav-menu a:hover,
.nav-menu a.active { color: var(--text); }

.nav-cta,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  font-weight: 700;
  min-height: 42px;
  padding: 0 18px;
}

.nav-cta,
.button.primary {
  color: #06111f !important;
  background: linear-gradient(135deg, var(--brand), var(--accent));
}

.button.secondary {
  color: var(--text);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.06);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.06);
}

.nav-toggle span:not(.sr-only) {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  background: var(--text);
}

.section-shell {
  width: min(var(--max), calc(100% - 32px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  gap: 48px;
  align-items: center;
  padding: 96px 0 72px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--brand);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1, h2, h3 { line-height: 1.18; margin: 0; }
h1 {
  max-width: 820px;
  font-size: clamp(2.7rem, 7vw, 5.8rem);
  letter-spacing: -0.07em;
}
h2 {
  font-size: clamp(2rem, 4vw, 3.35rem);
  letter-spacing: -0.045em;
}
h3 { font-size: 1.3rem; letter-spacing: -0.02em; }

.hero-text {
  max-width: 720px;
  margin: 24px 0 0;
  font-size: 1.16rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.hero-panel,
.feature-card,
.tool-card,
.news-card,
.intro-grid article,
.selection-note,
.best-practice,
.contact-section {
  border: 1px solid var(--line);
  background: linear-gradient(180deg, var(--panel-strong), rgba(255, 255, 255, 0.045));
  box-shadow: var(--shadow);
}

.hero-panel {
  padding: 24px;
  border-radius: var(--radius-lg);
}

.signal-card {
  min-height: 250px;
  padding: 28px;
  border-radius: 24px;
  background:
    linear-gradient(135deg, rgba(125, 211, 252, 0.22), rgba(192, 132, 252, 0.16)),
    rgba(255, 255, 255, 0.06);
}
.signal-label {
  display: inline-block;
  color: var(--brand);
  margin-bottom: 18px;
  font-weight: 800;
}
.signal-card strong {
  display: block;
  font-size: 2.1rem;
  line-height: 1.15;
  letter-spacing: -0.04em;
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 14px;
}
.metric-grid div {
  padding: 16px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.07);
}
.metric-grid strong { display: block; font-size: 1.65rem; }
.metric-grid span { color: var(--muted); font-size: 0.85rem; }

.intro-grid,
.card-grid,
.news-grid,
.practice-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.intro-grid article {
  padding: 24px;
  border-radius: var(--radius-md);
}
.icon { font-size: 2rem; }

.content-section { padding: 92px 0 0; }
.section-heading { max-width: 820px; margin-bottom: 34px; }
.section-heading p:last-child { font-size: 1.08rem; }

two-column,
.two-column {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.feature-card,
.tool-card,
.news-card,
.selection-note,
.best-practice {
  border-radius: var(--radius-lg);
  padding: 28px;
}
.feature-card.large { min-height: 360px; }
.feature-card.accent { background: linear-gradient(135deg, rgba(52, 211, 153, 0.16), rgba(125, 211, 252, 0.08)); }

.check-list { padding-left: 0; list-style: none; }
.check-list li {
  position: relative;
  padding-left: 28px;
  margin: 10px 0;
  color: var(--muted);
}
.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 900;
}

.best-practice { margin-top: 20px; }
.practice-grid { margin-top: 18px; }
.practice-grid div {
  padding: 20px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.06);
}
.practice-grid strong,
.practice-grid span { display: block; }
.practice-grid span { color: var(--muted); margin-top: 6px; }

.tools-grid { grid-template-columns: repeat(4, 1fr); }
.tool-card { box-shadow: none; }
.tool-card .tag {
  display: inline-block;
  margin: 12px 0;
  color: var(--accent);
  font-weight: 800;
}
.tool-card ol { padding-left: 18px; color: var(--muted); }

.model-table {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.06);
}
.table-row {
  display: grid;
  grid-template-columns: 0.75fr 1.35fr 1fr;
  gap: 18px;
  padding: 20px 24px;
  border-top: 1px solid var(--line);
}
.table-row:first-child { border-top: 0; }
.table-head {
  color: #06111f;
  font-weight: 900;
  background: linear-gradient(135deg, var(--brand), var(--accent));
}
.table-row span:not(:first-child) { color: var(--muted); }
.table-head span:not(:first-child) { color: #06111f; }

.selection-note { margin-top: 20px; }
.news-card a { color: var(--brand); font-weight: 800; }
.date {
  display: inline-flex;
  color: var(--accent);
  font-weight: 900;
  margin-bottom: 12px;
}

.contact-section {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 30px;
  margin-top: 96px;
  padding: 38px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, rgba(125, 211, 252, 0.18), rgba(192, 132, 252, 0.12));
}
.contact-section p { max-width: 720px; }

.site-footer {
  width: min(var(--max), calc(100% - 32px));
  margin: 0 auto;
  padding: 44px 0 54px;
  display: flex;
  justify-content: space-between;
  gap: 24px;
  border-top: 1px solid var(--line);
  margin-top: 70px;
}
.site-footer p { margin: 0; }

@media (max-width: 980px) {
  .hero,
  .two-column,
  .contact-section { grid-template-columns: 1fr; }
  .hero { padding-top: 70px; }
  .tools-grid,
  .intro-grid,
  .news-grid,
  .practice-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-section { display: grid; }
}

@media (max-width: 760px) {
  .nav-toggle { display: block; }
  .nav-menu {
    position: absolute;
    inset: 76px 16px auto 16px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    padding: 18px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: rgba(8, 17, 31, 0.96);
  }
  .nav-menu.open { display: flex; }
  .nav-menu a { padding: 10px; }
  .hero { grid-template-columns: 1fr; gap: 28px; }
  .metric-grid,
  .tools-grid,
  .intro-grid,
  .news-grid,
  .practice-grid { grid-template-columns: 1fr; }
  .table-row { grid-template-columns: 1fr; gap: 6px; }
  .site-footer { flex-direction: column; }
}