:root {
  --bg: #e8f1fa;
  --text: #1c1b1a;
  --muted: #6f6a63;
  --accent: #4f46e5;
  --accent-soft: #eef2ff;
  --border: #e7e2db;
  --card: #ffffff;
  --radius: 14px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #131210;
    --text: #ece9e4;
    --muted: #a09a91;
    --accent: #a5b4fc;
    --accent-soft: #232336;
    --border: #2c2a27;
    --card: #1c1b19;
  }
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans SC", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

.wrap { max-width: 760px; margin: 0 auto; padding: 0 22px; }

/* ---------- header ---------- */
header.site {
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  z-index: 10;
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 760px; margin: 0 auto; padding: 14px 22px;
}
.brand { font-weight: 800; font-size: 1.15rem; color: var(--text); }
.brand:hover { text-decoration: none; }
.nav-links { display: flex; gap: 20px; font-size: .95rem; }
.nav-links a { color: var(--muted); }
.nav-links a:hover, .nav-links a.active { color: var(--text); text-decoration: none; }

/* ---------- hero ---------- */
.hero { padding: 84px 0 56px; }
.hero .kicker {
  display: inline-block; font-size: .82rem; letter-spacing: .12em;
  color: var(--accent); background: var(--accent-soft);
  padding: 4px 12px; border-radius: 999px; margin-bottom: 18px;
  font-weight: 600;
}
.hero h1 { font-size: clamp(2.4rem, 6vw, 3.6rem); line-height: 1.2; letter-spacing: -0.01em; }
.hero p.lead { margin-top: 16px; font-size: 1.08rem; color: var(--muted); max-width: 34em; }
.hero .cta { margin-top: 28px; display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 10px 22px; border-radius: 999px;
  background: var(--accent); color: #fff; font-weight: 600; font-size: .95rem;
  border: 1px solid var(--accent);
}
.btn:hover { text-decoration: none; opacity: .88; }
.btn.ghost { background: transparent; color: var(--text); border: 1px solid var(--border); }
@media (prefers-color-scheme: dark) { .btn { color: #131210; } }

/* ---------- sections ---------- */
section.block { padding: 40px 0; }
section.block h2 {
  font-size: 1.25rem; margin-bottom: 18px;
  display: flex; align-items: center; gap: 10px;
}
section.block h2::after { content: ""; flex: 1; height: 1px; background: var(--border); }

.post-list { list-style: none; display: flex; flex-direction: column; gap: 14px; }
.post-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px 22px;
  transition: transform .15s ease, box-shadow .15s ease;
}
.post-card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.06); }
.post-card a.title { font-size: 1.08rem; font-weight: 700; color: var(--text); }
.post-card a.title:hover { color: var(--accent); text-decoration: none; }
.post-card .meta { font-size: .85rem; color: var(--muted); margin-top: 6px; }
.post-card .excerpt { margin-top: 8px; color: var(--muted); font-size: .95rem; }

/* ---------- article ---------- */
.article { padding: 56px 0; }
.article h1 { font-size: clamp(1.8rem, 4.5vw, 2.5rem); line-height: 1.3; margin-bottom: 10px; }
.article .meta { color: var(--muted); font-size: .9rem; margin-bottom: 32px; }
.article p { margin-bottom: 1.2em; }
.article h2 { font-size: 1.3rem; margin: 1.8em 0 .7em; }
.article ul, .article ol { margin: 0 0 1.2em 1.4em; }
.article blockquote {
  border-left: 3px solid var(--accent); padding-left: 16px;
  color: var(--muted); margin-bottom: 1.2em;
}

/* ---------- about ---------- */
.about-grid { display: flex; flex-direction: column; gap: 14px; }
.fact {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 18px 22px;
}
.fact strong { display: block; font-size: .85rem; color: var(--muted); margin-bottom: 4px; font-weight: 600; }

/* ---------- footer ---------- */
footer.site {
  border-top: 1px solid var(--border); margin-top: 48px;
  padding: 28px 0 40px; color: var(--muted); font-size: .88rem;
}
footer.site .wrap { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }

.back { display: inline-block; margin-top: 36px; font-size: .92rem; }