:root {
  --bg: #ffffff;
  --surface: #f6f7f9;
  --text: #1c1d1f;
  --muted: #6b6f76;
  --border: #e6e8eb;
  --accent: #185fa5;
  --accent-soft: #e6f1fb;
  --radius: 12px;
  --maxw: 880px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo { font-weight: 600; font-size: 16px; color: var(--text); text-decoration: none; }
.links a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 22px;
  font-size: 14px;
  transition: color 0.2s;
}
.links a:hover { color: var(--accent); }

/* layout */
main { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.section { padding: 64px 0; border-bottom: 1px solid var(--border); }
.section h2 { font-size: 22px; margin-bottom: 16px; }
.section p { color: var(--muted); margin-bottom: 14px; }

/* hero */
.hero { text-align: center; padding: 88px 0 72px; }
.avatar {
  width: 92px; height: 92px;
  margin: 0 auto 24px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  display: flex; align-items: center; justify-content: center;
  font-size: 34px; font-weight: 600;
}
.hero h1 { font-size: 34px; margin-bottom: 12px; }
.accent { color: var(--accent); }
.tagline { color: var(--muted); font-size: 16px; margin-bottom: 28px; }
.cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block;
  padding: 11px 22px;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--text);
  text-decoration: none;
  font-size: 14px;
  transition: all 0.2s;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.btn.primary:hover { opacity: 0.9; color: #fff; }

/* about */
.facts { list-style: none; display: flex; flex-wrap: wrap; gap: 12px; }
.facts li {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 14px;
  color: var(--muted);
  flex: 1 1 200px;
}
.facts strong { display: block; color: var(--text); font-size: 13px; margin-bottom: 4px; }

/* projects */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s, border-color 0.2s;
}
.card:hover { transform: translateY(-3px); border-color: var(--accent); }
.card h3 { font-size: 17px; margin-bottom: 8px; }
.card p { font-size: 14px; margin-bottom: 12px; }
.more { color: var(--accent); font-size: 13px; }

/* contact */
.contact-list { list-style: none; }
.contact-list li { padding: 8px 0; color: var(--muted); }
.contact-list a { color: var(--accent); text-decoration: none; }
.contact-list a:hover { text-decoration: underline; }

/* footer */
.footer {
  text-align: center;
  padding: 32px 20px;
  color: var(--muted);
  font-size: 13px;
}
.footer a { color: var(--muted); text-decoration: none; }
.footer a:hover { color: var(--accent); }

@media (max-width: 600px) {
  .hero h1 { font-size: 28px; }
  .section { padding: 48px 0; }
}