:root {
  --brand-cyan: #22d3ee;
  --brand-blue: #3b82f6;
  --bg: #0b1120;
  --bg-soft: #111a2e;
  --fg: #e2e8f0;
  --fg-dim: #94a3b8;
  --card: #16213a;
  --border: #243049;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "MiSans VF",
    "PingFang SC", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.65;
}

a { color: var(--brand-cyan); text-decoration: none; }
a:hover { color: var(--brand-blue); }

.site-header {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 0.9rem 1.5rem;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand { display: flex; align-items: center; gap: 0.6rem; font-weight: 700; }
.brand-logo { height: 28px; width: 28px; }
.brand-name {
  font-size: 1.1rem;
  background: linear-gradient(90deg, var(--brand-cyan), var(--brand-blue));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.site-nav { display: flex; gap: 1.2rem; flex: 1; }
.site-nav a { color: var(--fg-dim); font-weight: 500; }
.site-nav a:hover { color: var(--fg); }

.lang-switch { display: flex; gap: 0.6rem; font-size: 0.9rem; }
.lang-switch .current { color: var(--brand-cyan); font-weight: 700; }
.lang-switch a { color: var(--fg-dim); }

.site-main { max-width: 920px; margin: 0 auto; padding: 2.5rem 1.5rem 4rem; }

.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem;
  text-align: center;
  color: var(--fg-dim);
  font-size: 0.85rem;
}
.site-footer code { color: var(--brand-cyan); }

/* 首页 Hero */
.hero {
  text-align: center;
  padding: 3rem 0 2rem;
}
.hero h1 {
  font-size: 2.6rem;
  margin: 0 0 0.5rem;
  background: linear-gradient(90deg, var(--brand-cyan), var(--brand-blue));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero .tagline { font-size: 1.2rem; color: var(--fg-dim); margin-bottom: 1.8rem; }
.hero .cta { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 0.7rem 1.6rem;
  border-radius: 0.6rem;
  font-weight: 600;
  border: 1px solid var(--border);
}
.btn-primary {
  background: linear-gradient(90deg, var(--brand-cyan), var(--brand-blue));
  color: #04121f;
  border: none;
}
.btn-ghost { color: var(--fg); background: var(--card); }

/* 特性网格 */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.2rem;
  margin-top: 1.5rem;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 0.8rem;
  padding: 1.3rem;
}
.card h3 { margin: 0 0 0.4rem; color: var(--brand-cyan); }
.card p { margin: 0; color: var(--fg-dim); font-size: 0.95rem; }

.prose { color: var(--fg); }
.prose h2 { margin-top: 2rem; color: var(--brand-blue); }
.prose code {
  background: var(--bg-soft);
  padding: 0.1rem 0.4rem;
  border-radius: 0.3rem;
  font-size: 0.9em;
}
.prose pre {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 0.6rem;
  padding: 1rem;
  overflow-x: auto;
}
.prose pre code { background: none; padding: 0; }

.page-list { list-style: none; padding: 0; }
.page-list li { padding: 0.4rem 0; border-bottom: 1px solid var(--border); }