:root {
  --bg: #0a0a0a;
  --surface: #131316;
  --text: #f0f0f2;
  --text-muted: #9a9aa3;
  --accent: #34c77b;
  --border: #26262c;
  --radius: 14px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI",
          Roboto, Inter, system-ui, sans-serif;
}

* { box-sizing: border-box; }

html { font-size: 16px; -webkit-font-smoothing: antialiased; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-feature-settings: "ss01" on, "cv11" on;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 24px 96px;
}

header.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 48px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

header.brand .mark {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background:
    radial-gradient(circle at 30% 28%, #56dd95 0%, #34c77b 38%, #1b8e5a 100%);
}

header.brand .name {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

header.brand .lang {
  margin-left: auto;
  font-size: 14px;
  color: var(--text-muted);
}

header.brand .lang a {
  color: var(--text-muted);
  text-decoration: none;
  margin-left: 12px;
}

header.brand .lang a:hover,
header.brand .lang a.active {
  color: var(--accent);
}

h1 {
  font-size: 32px;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
  font-weight: 700;
}

.subtitle {
  color: var(--text-muted);
  font-size: 16px;
  margin-bottom: 40px;
}

h2 {
  font-size: 19px;
  letter-spacing: -0.01em;
  margin: 40px 0 12px;
  font-weight: 600;
}

p, li {
  font-size: 15.5px;
  color: var(--text);
}

ul {
  padding-left: 22px;
}

li {
  margin-bottom: 6px;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin: 32px 0;
}

.card h2:first-child { margin-top: 0; }

code {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  background: var(--surface);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 13px;
  color: var(--accent);
}

footer {
  margin-top: 80px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-muted);
}

footer a { color: var(--text-muted); }
footer a:hover { color: var(--accent); }

.cta {
  display: inline-block;
  margin-top: 8px;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--accent);
  color: #0a0a0a;
  font-weight: 600;
  font-size: 14px;
}

.cta:hover { text-decoration: none; opacity: 0.92; }

@media (max-width: 600px) {
  main { padding: 32px 20px 64px; }
  h1 { font-size: 28px; }
}