:root {
  --bg: #0a0a0f;
  --bg-soft: #12121a;
  --card: #15151f;
  --border: #26263400;
  --border-vis: #262634;
  --text: #e8e8f0;
  --muted: #9a9ab0;
  --brand: #6366f1;
  --brand-2: #a855f7;
  --accent: #22d3ee;
  --ok: #34d399;
  --warn: #fbbf24;
  --danger: #fb7185;
  --radius: 14px;
  --maxw: 1100px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
code { font-family: var(--mono); font-size: 0.92em; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.narrow { max-width: 820px; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: saturate(140%) blur(12px);
  background: rgba(10, 10, 15, 0.72);
  border-bottom: 1px solid var(--border-vis);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.brand-mark {
  font-family: var(--mono); color: #fff; background: linear-gradient(135deg, var(--brand), var(--brand-2));
  width: 30px; height: 30px; border-radius: 9px; display: grid; place-items: center; font-size: 14px;
}
.brand-name { letter-spacing: -0.01em; }
.nav-links { display: flex; align-items: center; gap: 22px; font-size: 0.93rem; color: var(--muted); }
.nav-links a:hover { color: var(--text); }
.nav-cta { color: var(--text) !important; font-weight: 600; }
@media (max-width: 720px) { .nav-links a:not(.nav-cta) { display: none; } }

/* Hero */
.hero { position: relative; overflow: hidden; padding: 110px 0 90px; text-align: center; }
.hero-glow {
  position: absolute; inset: -40% 0 auto 0; height: 600px;
  background: radial-gradient(60% 60% at 50% 0%, rgba(99,102,241,0.28), transparent 70%),
              radial-gradient(40% 40% at 70% 10%, rgba(168,85,247,0.20), transparent 70%);
  filter: blur(8px); pointer-events: none;
}
.hero-inner { position: relative; max-width: 880px; margin: 0 auto; padding: 0 24px; }
.eyebrow {
  display: inline-block; font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.04em;
  color: var(--accent); border: 1px solid var(--border-vis); border-radius: 999px;
  padding: 5px 14px; margin-bottom: 26px; background: var(--bg-soft);
}
.hero h1 { font-size: clamp(2.4rem, 6vw, 4rem); line-height: 1.05; letter-spacing: -0.03em; margin: 0 0 22px; font-weight: 800; }
.grad { background: linear-gradient(120deg, var(--brand), var(--brand-2) 50%, var(--accent)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.lede { font-size: clamp(1.05rem, 2.2vw, 1.3rem); color: var(--muted); max-width: 680px; margin: 0 auto 34px; }
.lede strong { color: var(--text); font-weight: 600; }

.cta-row { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-bottom: 30px; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 22px; border-radius: 11px; font-weight: 600; font-size: 0.98rem; transition: transform .12s ease, background .2s ease, border-color .2s; }
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: linear-gradient(135deg, var(--brand), var(--brand-2)); color: #fff; box-shadow: 0 8px 30px rgba(99,102,241,0.35); }
.btn-ghost { border: 1px solid var(--border-vis); color: var(--text); background: var(--bg-soft); }
.btn-ghost:hover { border-color: var(--brand); }

.install {
  display: inline-flex; align-items: center; gap: 14px; margin: 0 auto;
  background: var(--bg-soft); border: 1px solid var(--border-vis); border-radius: 12px;
  padding: 10px 12px 10px 18px; font-family: var(--mono); font-size: 0.92rem;
}
.install code { color: var(--text); }
.copy { font-family: var(--sans); cursor: pointer; border: 1px solid var(--border-vis); background: var(--card); color: var(--muted); border-radius: 8px; padding: 6px 12px; font-size: 0.82rem; }
.copy:hover { color: var(--text); border-color: var(--brand); }

/* Sections */
section { padding: 70px 0; }
.section-title { font-size: clamp(1.6rem, 3.5vw, 2.3rem); letter-spacing: -0.02em; margin: 0 0 12px; text-align: center; font-weight: 800; }
.section-sub { color: var(--muted); text-align: center; max-width: 640px; margin: 0 auto 44px; }
h2 { letter-spacing: -0.02em; }
.problem h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin-bottom: 18px; }
.problem p { color: var(--muted); font-size: 1.05rem; }
.problem em { color: var(--text); font-style: normal; font-weight: 600; }
.problem a, .compare a { color: var(--accent); }

/* Cards */
.card-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
@media (max-width: 720px) { .card-grid { grid-template-columns: 1fr; } }
.card {
  background: var(--card); border: 1px solid var(--border-vis); border-radius: var(--radius);
  padding: 26px; transition: transform .15s ease, border-color .2s;
}
.card:hover { transform: translateY(-3px); border-color: var(--brand); }
.card-tag { font-family: var(--mono); font-size: 0.74rem; letter-spacing: 0.05em; color: var(--accent); text-transform: uppercase; margin-bottom: 12px; }
.card h3 { margin: 0 0 10px; font-size: 1.2rem; letter-spacing: -0.01em; }
.card p { color: var(--muted); margin: 0 0 18px; font-size: 0.97rem; }
.card-link { color: var(--brand); font-family: var(--mono); font-size: 0.85rem; font-weight: 600; }
.card-link:hover { color: var(--accent); }

/* Tables */
.data-table { width: 100%; border-collapse: collapse; font-size: 0.95rem; border: 1px solid var(--border-vis); border-radius: var(--radius); overflow: hidden; }
.data-table th, .data-table td { text-align: left; padding: 13px 16px; border-bottom: 1px solid var(--border-vis); vertical-align: top; }
.data-table thead th { background: var(--bg-soft); color: var(--muted); font-weight: 600; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.03em; }
.data-table tbody tr:last-child td { border-bottom: none; }
.data-table td:first-child { color: var(--text); font-weight: 500; }
.data-table code { color: var(--accent); }
.pill { display: inline-block; font-family: var(--mono); font-size: 0.78rem; padding: 3px 10px; border-radius: 999px; font-weight: 600; }
.pill-ko { background: rgba(251,113,133,0.15); color: var(--danger); }
.pill-req { background: rgba(99,102,241,0.18); color: #a5b4fc; }
.pill-pref { background: rgba(34,211,238,0.15); color: var(--accent); }
.pill-opt { background: rgba(154,154,176,0.15); color: var(--muted); }

/* Code block */
.code {
  background: var(--bg-soft); border: 1px solid var(--border-vis); border-radius: var(--radius);
  padding: 22px 24px; overflow-x: auto; font-family: var(--mono); font-size: 0.88rem; line-height: 1.7;
  color: #d6d6e6; text-align: left;
}
.code .k { color: #c084fc; }
.code .s { color: #6ee7b7; }
.code .c { color: #6b6b80; font-style: italic; }

/* Final CTA */
.final-cta { text-align: center; }
.final-cta h2 { font-size: clamp(1.8rem, 4vw, 2.6rem); margin: 0 0 12px; }
.final-cta p { color: var(--muted); margin: 0 0 28px; }

/* Footer */
.footer { border-top: 1px solid var(--border-vis); padding: 34px 0; color: var(--muted); font-size: 0.9rem; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 14px; }
.footer nav { display: flex; gap: 20px; }
.footer a:hover { color: var(--text); }

/* Alternating section bg */
.problem, .levels, .compare { background: linear-gradient(180deg, transparent, rgba(18,18,26,0.5), transparent); }