:root {
  --text: #1a1d21;
  --muted: #5c636b;
  --accent: #1f3a5f;
  --border: #e3e6ea;
  --maxw: 46rem;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: #fff;
}

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 1.5rem; }

/* ---------- header ---------- */
.site-header {
  border-bottom: 1px solid var(--border);
  padding: 1.25rem 0;
}

.site-header .wrap {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.wordmark {
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent);
  text-decoration: none;
}

.site-header nav a {
  font-size: 0.875rem;
  color: var(--muted);
  text-decoration: none;
  margin-left: 1.25rem;
}

.site-header nav a:hover { color: var(--accent); }

/* ---------- hero ---------- */
.hero { padding: 4rem 0 3rem; }

.hero h1 {
  font-size: 1.875rem;
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 0.75rem;
}

.hero p {
  font-size: 1.125rem;
  color: var(--muted);
  margin: 0;
}

/* ---------- sections ---------- */
section { padding: 2.5rem 0; border-top: 1px solid var(--border); }

h2 {
  font-size: 0.8125rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin: 0 0 1rem;
}

h3 {
  font-size: 1rem;
  font-weight: 600;
  margin: 1.75rem 0 0.5rem;
}

p { margin: 0 0 1rem; }
p:last-child { margin-bottom: 0; }

ul { margin: 0 0 1rem; padding-left: 1.25rem; }
li { margin-bottom: 0.375rem; }

a { color: var(--accent); }

.meta {
  margin: 0;
  padding: 0;
  list-style: none;
}

.meta li {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
}

.meta li:last-child { border-bottom: 0; }

.meta .k {
  flex: 0 0 12rem;
  color: var(--muted);
  font-size: 0.9375rem;
}

/* ---------- placeholder marker ---------- */
.ph {
  background: #fff3bf;
  border-bottom: 1px dashed #d9a300;
  padding: 0 0.15em;
  font-weight: 600;
}

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0 3rem;
  font-size: 0.875rem;
  color: var(--muted);
}

.site-footer a { color: var(--muted); }

/* ---------- responsive ---------- */
@media (max-width: 640px) {
  .hero { padding: 2.5rem 0 2rem; }
  .hero h1 { font-size: 1.5rem; }
  .hero p { font-size: 1rem; }
  .meta .k { flex-basis: 100%; }
}