:root {
  color-scheme: dark;
  --ink: #f5f4ef;
  --muted: #aaa8a0;
  --line: rgba(255, 255, 255, 0.13);
  --panel: rgba(255, 255, 255, 0.045);
  --accent: #d7ff64;
  --page: #0a0a0a;
  --max: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 76% -10%, rgba(215, 255, 100, 0.09), transparent 32rem),
    var(--page);
  color: var(--ink);
  font-family: "Helvetica Neue", "PingFang SC", "Noto Sans SC", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

.shell {
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(10, 10, 10, 0.82);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(18px);
}

.nav {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  text-decoration: none;
  letter-spacing: -0.02em;
  font-weight: 700;
}

.brand small {
  margin-left: 10px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.13em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  color: var(--muted);
  font-size: 14px;
}

.nav-links a { text-decoration: none; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--ink); }

.hero {
  padding: 116px 0 92px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 24px;
  color: var(--accent);
  font-family: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.eyebrow::before {
  width: 7px;
  height: 7px;
  content: "";
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 18px currentColor;
}

h1, h2, h3, p { margin-top: 0; }

h1 {
  max-width: 920px;
  margin-bottom: 28px;
  font-size: clamp(46px, 7.4vw, 92px);
  font-weight: 520;
  line-height: 0.98;
  letter-spacing: -0.057em;
}

.lead {
  max-width: 750px;
  color: #c5c3bc;
  font-size: clamp(18px, 2.2vw, 25px);
  line-height: 1.65;
  letter-spacing: -0.02em;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 38px;
}

.button {
  min-height: 48px;
  padding: 0 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  text-decoration: none;
  font-size: 14px;
  transition: 160ms ease;
}

.button.primary { background: var(--ink); color: #101010; }
.button:hover { transform: translateY(-1px); border-color: rgba(255, 255, 255, 0.34); }

.section { padding: 84px 0; border-bottom: 1px solid var(--line); }
.section h2 { max-width: 790px; font-size: clamp(32px, 5vw, 56px); font-weight: 520; letter-spacing: -0.045em; line-height: 1.08; }
.section-copy { max-width: 720px; color: var(--muted); font-size: 18px; line-height: 1.75; }

.grid {
  margin-top: 44px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.card {
  min-height: 250px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--panel);
}

.card .index {
  display: block;
  margin-bottom: 64px;
  color: var(--accent);
  font-family: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
}

.card h3 { margin-bottom: 12px; font-size: 20px; font-weight: 520; }
.card p { margin-bottom: 0; color: var(--muted); line-height: 1.65; }

.steps { counter-reset: steps; margin-top: 42px; border-top: 1px solid var(--line); }
.step { counter-increment: steps; padding: 25px 0; display: grid; grid-template-columns: 72px minmax(0, 1fr); border-bottom: 1px solid var(--line); }
.step::before { content: "0" counter(steps); color: var(--accent); font-family: "JetBrains Mono", "SFMono-Regular", Consolas, monospace; font-size: 12px; padding-top: 4px; }
.step h3 { margin-bottom: 7px; font-size: 19px; font-weight: 520; }
.step p { margin-bottom: 0; color: var(--muted); line-height: 1.6; }

.checkout-layout { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(300px, 0.8fr); gap: 16px; align-items: start; }
.order-panel, .summary-panel { padding: clamp(25px, 4vw, 42px); border: 1px solid var(--line); border-radius: 24px; background: var(--panel); }
.summary-panel { position: sticky; top: 96px; }
.choice { padding: 18px 0; display: flex; justify-content: space-between; gap: 18px; border-bottom: 1px solid var(--line); }
.choice strong { font-size: 16px; font-weight: 520; }
.choice span { color: var(--muted); font-size: 14px; text-align: right; }
.notice { margin-top: 28px; padding: 18px; border: 1px solid rgba(215, 255, 100, 0.28); border-radius: 14px; background: rgba(215, 255, 100, 0.055); color: #dfe5cb; font-size: 14px; line-height: 1.7; }
.meta { margin: 0; display: grid; gap: 14px; }
.meta.spaced { margin-top: 28px; }
.meta div { display: flex; justify-content: space-between; gap: 16px; }
.meta dt { color: var(--muted); }
.meta dd { margin: 0; text-align: right; }

.footer { padding: 38px 0 48px; color: #8d8b84; font-size: 12px; }
.footer-row { display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; }
.footer p { margin-bottom: 8px; }
.footer a { color: #b8b6af; text-decoration: none; }
.footer a:hover { color: var(--ink); }

@media (max-width: 820px) {
  .nav { min-height: 64px; }
  .nav-links { gap: 14px; font-size: 13px; }
  .brand small { display: none; }
  .hero { padding: 82px 0 68px; }
  .grid, .checkout-layout { grid-template-columns: 1fr; }
  .card { min-height: auto; }
  .card .index { margin-bottom: 40px; }
  .summary-panel { position: static; }
}

@media (max-width: 520px) {
  .shell { width: min(calc(100% - 28px), var(--max)); }
  .nav-links a:first-child { display: none; }
  h1 { font-size: 45px; }
  .section { padding: 64px 0; }
  .footer-row { display: block; }
}