:root {
  --bg: #ffffff;
  --bg-alt: #f6f7f9;
  --text: #1d2330;
  --text-soft: #5c6577;
  --line: #e3e6eb;
  --accent: #2b6cb0;
  --accent-dark: #1f4e7f;
  --header: #1c2430;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

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

.wrap {
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- header ---------- */

.site-header {
  background: var(--header);
  border-bottom: 1px solid rgba(255, 255, 255, .06);
  position: sticky;
  top: 0;
  z-index: 20;
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 62px;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 600;
  letter-spacing: .3px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-size: 15px;
  font-weight: 700;
}

.brand-text { font-size: 16px; }

.nav { display: flex; gap: 26px; }

.nav a {
  color: rgba(255, 255, 255, .72);
  font-size: 14.5px;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}

.nav a:hover { color: #fff; }

.nav a.active {
  color: #fff;
  border-bottom-color: var(--accent);
}

/* ---------- hero ---------- */

.hero {
  padding: 84px 0 76px;
  background: linear-gradient(180deg, #f9fafc 0%, #ffffff 100%);
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  font-size: 12.5px;
  letter-spacing: 1.6px;
  color: var(--text-soft);
  text-transform: uppercase;
  margin: 0 0 14px;
}

.hero h1 {
  font-size: 40px;
  line-height: 1.3;
  margin: 0 0 20px;
  font-weight: 700;
  letter-spacing: -.5px;
}

.lead {
  font-size: 17px;
  color: var(--text-soft);
  max-width: 620px;
  margin: 0 0 30px;
}

.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 10px 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 15px;
  color: var(--text);
  background: #fff;
  transition: .18s ease;
}

.btn:hover {
  border-color: #c8ced8;
  transform: translateY(-1px);
  color: var(--text);
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-dark);
  border-color: var(--accent-dark);
  color: #fff;
}

/* ---------- sections ---------- */

.section { padding: 64px 0; }

.section-alt {
  background: var(--bg-alt);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-title {
  font-size: 22px;
  font-weight: 600;
  margin: 0 0 28px;
  padding-left: 12px;
  border-left: 3px solid var(--accent);
  line-height: 1.4;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 24px;
  transition: .18s ease;
}

.card:hover {
  border-color: #cfd6e0;
  box-shadow: 0 6px 20px rgba(28, 36, 48, .06);
  transform: translateY(-2px);
}

.card h3 {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 600;
}

.card p {
  margin: 0;
  font-size: 14.5px;
  color: var(--text-soft);
}

/* ---------- timeline ---------- */

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

.timeline li {
  display: flex;
  gap: 22px;
  padding: 18px 0;
  border-bottom: 1px dashed var(--line);
}

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

.timeline .time {
  flex: 0 0 76px;
  font-size: 13px;
  color: var(--text-soft);
  font-variant-numeric: tabular-nums;
  padding-top: 3px;
}

.timeline h4 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 600;
}

.timeline p {
  margin: 0;
  font-size: 14.5px;
  color: var(--text-soft);
}

/* ---------- stats ---------- */

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 20px;
  text-align: center;
}

.stat {
  padding: 22px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
}

.stat strong {
  display: block;
  font-size: 30px;
  color: var(--accent);
  font-weight: 700;
  line-height: 1.2;
}

.stat span {
  font-size: 13.5px;
  color: var(--text-soft);
}

/* ---------- prose (about / notes) ---------- */

.prose {
  max-width: 760px;
  font-size: 15.5px;
}

.prose h2 {
  font-size: 19px;
  margin: 34px 0 12px;
  font-weight: 600;
}

.prose p { margin: 0 0 14px; color: #333c4d; }

.prose ul { margin: 0 0 16px; padding-left: 22px; color: #333c4d; }

.prose li { margin-bottom: 6px; }

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

.post-list li {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

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

.post-list h3 { margin: 0 0 6px; font-size: 17px; font-weight: 600; }

.post-list .meta {
  font-size: 13px;
  color: var(--text-soft);
  margin-bottom: 8px;
}

.post-list p { margin: 0; font-size: 14.5px; color: var(--text-soft); }

/* ---------- contact ---------- */

.contact-table {
  border-collapse: collapse;
  width: 100%;
  max-width: 620px;
  font-size: 15px;
}

.contact-table th,
.contact-table td {
  text-align: left;
  padding: 12px 10px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

.contact-table th {
  width: 130px;
  color: var(--text-soft);
  font-weight: 500;
}

/* ---------- footer ---------- */

.site-footer {
  background: var(--header);
  color: rgba(255, 255, 255, .66);
  padding: 46px 0 26px;
  margin-top: 10px;
  font-size: 14px;
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 28px;
  margin-bottom: 30px;
}

.site-footer h5 {
  color: #fff;
  font-size: 14px;
  margin: 0 0 10px;
  font-weight: 600;
}

.site-footer p { margin: 0 0 6px; }

.copyright {
  border-top: 1px solid rgba(255, 255, 255, .1);
  padding-top: 18px;
  margin: 0;
  font-size: 13px;
  color: rgba(255, 255, 255, .45);
}

/* ---------- 404 ---------- */

.center-page {
  min-height: 58vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 0;
}

.center-page h1 {
  font-size: 64px;
  margin: 0 0 8px;
  color: var(--accent);
  font-weight: 700;
}

.center-page p { color: var(--text-soft); margin: 0 0 22px; }

/* ---------- responsive ---------- */

@media (max-width: 720px) {
  .site-header .wrap {
    height: auto;
    padding-top: 12px;
    padding-bottom: 12px;
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }
  .nav { gap: 18px; flex-wrap: wrap; }
  .hero { padding: 56px 0 52px; }
  .hero h1 { font-size: 29px; }
  .lead { font-size: 15.5px; }
  .section { padding: 46px 0; }
  .timeline li { flex-direction: column; gap: 4px; }
  .timeline .time { flex: none; }
  .center-page h1 { font-size: 46px; }
}