:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro SC", "PingFang SC", "Noto Sans SC", "Segoe UI", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Roboto Mono", Consolas, monospace;
  --bg: #fbfbfc;
  --bg-soft: #f3f4f6;
  --ink: #101418;
  --muted: #5d6673;
  --faint: #8b94a3;
  --rule: rgba(16, 20, 24, 0.09);
  --rule-strong: rgba(16, 20, 24, 0.18);
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.07);
  --accent-soft-2: rgba(37, 99, 235, 0.12);
  --warm: #d97706;
  --warm-soft: rgba(217, 119, 6, 0.09);
  --green: #1e7a4f;
  --red: #c0392b;
  --violet: #7c3aed;
  --radius: 14px;
  --shadow-sm: 0 1px 2px rgba(16, 20, 24, 0.04), 0 1px 3px rgba(16, 20, 24, 0.06);
  --shadow-md: 0 2px 6px rgba(16, 20, 24, 0.05), 0 8px 24px rgba(16, 20, 24, 0.07);
  --card-bg: #ffffff;
}

html[data-theme="dark"] {
  --bg: #0b0e12;
  --bg-soft: #12161c;
  --ink: #eef0f3;
  --muted: #9aa3af;
  --faint: #8b94a3;
  --rule: rgba(238, 240, 243, 0.1);
  --rule-strong: rgba(238, 240, 243, 0.22);
  --accent: #60a5fa;
  --accent-strong: #93c5fd;
  --accent-soft: rgba(96, 165, 250, 0.1);
  --accent-soft-2: rgba(96, 165, 250, 0.18);
  --warm: #f0a35e;
  --warm-soft: rgba(240, 163, 94, 0.12);
  --green: #34d399;
  --red: #f87171;
  --violet: #a78bfa;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.35), 0 12px 32px rgba(0, 0, 0, 0.4);
  --card-bg: #12161c;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--bg);
  font-variant-numeric: tabular-nums;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s ease, color 0.3s ease;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
::selection { background: var(--accent-soft-2); }

/* ---------- 导航 ---------- */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 28px;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--rule);
}
.navbar .brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  letter-spacing: 0.01em;
}
.navbar .brand .dot {
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}
.navbar nav { display: flex; align-items: center; gap: 4px; }
.navbar nav a {
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--muted);
  transition: color 0.2s, background 0.2s;
}
.navbar nav a:hover { color: var(--ink); background: var(--accent-soft); }
.navbar nav a.active { color: var(--accent); background: var(--accent-soft); font-weight: 600; }
#theme-toggle {
  margin-left: 8px;
  padding: 6px 12px;
  border: 1px solid var(--rule-strong);
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  font-family: inherit;
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s;
}
#theme-toggle:hover { color: var(--ink); border-color: var(--accent); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  padding: 84px 28px 56px;
  text-align: center;
  border-bottom: 1px solid var(--rule);
  background:
    radial-gradient(800px 320px at 50% -10%, var(--accent-soft-2), transparent 60%),
    radial-gradient(600px 260px at 85% 10%, var(--warm-soft), transparent 55%),
    var(--bg);
}
.hero::before {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--rule) 1px, transparent 1px),
    linear-gradient(90deg, var(--rule) 1px, transparent 1px);
  background-size: 44px 44px;
  -webkit-mask-image: radial-gradient(720px 320px at 50% 0%, #000 30%, transparent 75%);
  mask-image: radial-gradient(720px 320px at 50% 0%, #000 30%, transparent 75%);
  pointer-events: none;
}
.hero > * { position: relative; }
.hero .kicker {
  display: inline-block;
  padding: 5px 12px;
  border: 1px solid var(--accent-soft-2);
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
}
.hero h1 {
  margin: 20px auto 14px;
  max-width: 860px;
  font-size: clamp(28px, 5vw, 48px);
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -0.02em;
}
.hero h1 .grad {
  background: linear-gradient(100deg, var(--accent) 0%, var(--violet) 55%, var(--warm) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.hero .sub {
  max-width: 720px;
  margin: 0 auto 28px;
  color: var(--muted);
  font-size: 16px;
}
.cta-row { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 11px 22px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s, background 0.2s;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(100deg, var(--accent), var(--accent-strong));
  color: #fff;
  box-shadow: 0 4px 14px var(--accent-soft-2);
}
.btn-primary:hover { box-shadow: 0 6px 22px var(--accent-soft-2); }
.btn-outline {
  border-color: var(--rule-strong);
  color: var(--ink);
  background: var(--card-bg);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }
.hero-visual {
  margin: 44px auto 0;
  max-width: 860px;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--rule);
}
.hero-visual img { width: 100%; height: 320px; object-fit: cover; }
.hero-visual .caption {
  padding: 10px 16px;
  font-size: 12.5px;
  color: var(--faint);
  background: var(--bg-soft);
  text-align: left;
}

/* ---------- 通用 section ---------- */
.section { padding: 56px 28px; }
.wrap { max-width: 1080px; margin: 0 auto; }
.section-title {
  margin: 0 0 6px;
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.section-sub { margin: 0 0 26px; color: var(--muted); }

/* ---------- KPI ---------- */
.kpi-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.kpi {
  padding: 22px 20px;
  border-radius: var(--radius);
  background: var(--card-bg);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}
.kpi:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); border-color: var(--accent-soft-2); }
.kpi .num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(100deg, var(--accent), var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.kpi .label { margin-top: 4px; font-size: 14.5px; font-weight: 700; }
.kpi .note { margin-top: 4px; font-size: 12.5px; color: var(--faint); line-height: 1.55; }

/* ---------- 文章卡片 ---------- */
.post-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.post-card {
  display: flex;
  flex-direction: column;
  padding: 22px;
  border-radius: var(--radius);
  background: var(--card-bg);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}
.post-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: var(--accent-soft-2); }
.post-card .date {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.03em;
}
.post-card h2 { margin: 10px 0 10px; font-size: 18px; line-height: 1.5; font-weight: 700; }
.post-card h2 a:hover { color: var(--accent); }
.post-card .desc { flex: 1; margin: 0 0 14px; font-size: 14px; color: var(--muted); line-height: 1.7; }
.tags { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 14px; }
.tag {
  padding: 3px 9px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
}
.more { font-size: 14px; font-weight: 600; color: var(--accent); }
.more:hover { text-decoration: underline; }

/* ---------- split ---------- */
.split { display: grid; grid-template-columns: 380px 1fr; gap: 28px; align-items: start; }
.img-card {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-sm);
}
.img-card img { width: 100%; height: 240px; object-fit: cover; }
.img-card .caption {
  padding: 10px 14px;
  font-size: 12.5px;
  color: var(--faint);
  background: var(--bg-soft);
  line-height: 1.6;
}
.split p { color: var(--muted); }
.split p strong { color: var(--ink); }

/* ---------- CTA band ---------- */
.cta-band {
  padding: 34px 32px;
  border-radius: var(--radius);
  background:
    linear-gradient(120deg, var(--accent-soft), transparent 55%),
    var(--card-bg);
  border: 1px solid var(--rule);
  text-align: center;
  box-shadow: var(--shadow-sm);
}
.cta-band h2 { margin: 0 0 8px; font-size: 22px; font-weight: 800; }
.cta-band p { margin: 0 auto 18px; max-width: 560px; color: var(--muted); }

/* ---------- footer ---------- */
.site-footer {
  padding: 28px;
  border-top: 1px solid var(--rule);
  color: var(--faint);
  font-size: 13px;
  text-align: center;
  line-height: 1.9;
}
.site-footer .f-links {
  display: flex;
  justify-content: center;
  gap: 18px;
  color: var(--muted);
  font-weight: 600;
}
.site-footer .disclosure { margin-top: 6px; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .kpi-grid { grid-template-columns: repeat(2, 1fr); }
  .post-grid { grid-template-columns: 1fr; }
  .split { grid-template-columns: 1fr; }
  .navbar { flex-wrap: wrap; padding: 10px 16px; }
  .hero { padding: 56px 18px 40px; }
  .section { padding: 40px 18px; }
  .hero-visual img { height: 220px; }
}