/* ─── Design Tokens ───────────────────────────────────── */
:root {
  --bg:           #F5F7FA;
  --surface:      #FFFFFF;
  --surface-2:    #EEF2F8;
  --primary:      #111827;
  --secondary:    #6B7A8D;
  --muted:        #9CA8B8;
  --accent:       #1D4ED8;
  --accent-light: #EEF2FF;
  --accent-warm:  #B45309;
  --warm-light:   #FEF3C7;
  --border:       #E2E8F0;
  --border-dark:  #CBD5E1;
  --green:        #15803D;
  --green-light:  #DCFCE7;
  --radius:       10px;
  --radius-sm:    6px;

  --font-serif:   'IBM Plex Serif', 'Noto Serif SC', Georgia, serif;
  --font-sans:    'IBM Plex Sans', 'Noto Sans SC', system-ui, sans-serif;
  --font-mono:    'IBM Plex Mono', 'JetBrains Mono', 'Courier New', monospace;
}

/* ─── Reset ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  background: var(--bg);
  color: var(--primary);
  font-family: var(--font-sans);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; }

/* ─── Layout ──────────────────────────────────────────── */
.wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 28px;
}

/* ─── Nav ─────────────────────────────────────────────── */
#nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(245,247,250,.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 28px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  font-family: var(--font-mono);
  font-size: .88rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: -.01em;
}
.logo em { font-style: normal; color: var(--muted); }
.nav-links {
  display: flex;
  list-style: none;
  gap: 28px;
}
.nav-links a {
  font-size: .82rem;
  font-weight: 500;
  color: var(--secondary);
  transition: color .15s;
  letter-spacing: .02em;
}
.nav-links a:hover { color: var(--accent); }
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-toggle span {
  width: 20px; height: 1.5px;
  background: var(--secondary);
  border-radius: 2px;
}

/* ─── Hero ────────────────────────────────────────────── */
#hero {
  padding: 72px 0 56px;
  border-bottom: 1px solid var(--border);
}
.hero-inner {
  display: flex;
  gap: 36px;
  align-items: flex-start;
}
.avatar {
  flex-shrink: 0;
  width: 96px; height: 96px;
  border-radius: 50%;
  overflow: hidden;
  border: 3px solid var(--surface);
  box-shadow: 0 0 0 1px var(--border), 0 4px 16px rgba(29,78,216,.12);
}
.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  display: block;
}
.hero-text {}
.hero-name {
  font-family: var(--font-serif);
  font-size: clamp(1.9rem, 5vw, 2.6rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -.02em;
  color: var(--primary);
  margin-bottom: 6px;
}
.hero-name span {
  font-family: var(--font-sans);
  font-size: .85em;
  font-weight: 400;
  color: var(--secondary);
  margin-left: 10px;
}
.hero-title {
  font-size: .9rem;
  color: var(--secondary);
  margin-bottom: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}
.hero-title .sep { color: var(--border-dark); }
.hero-desc {
  font-size: .97rem;
  color: var(--secondary);
  line-height: 1.8;
  max-width: 580px;
  margin-bottom: 22px;
}
.hero-links {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.hero-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: .82rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-dark);
  color: var(--secondary);
  background: var(--surface);
  transition: all .15s;
}
.hero-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-light);
}
.hero-link svg { flex-shrink: 0; }

/* ─── Section ─────────────────────────────────────────── */
.section {
  padding: 60px 0;
  border-bottom: 1px solid var(--border);
}
.section:last-of-type { border-bottom: none; }

/* ─── Section Label (签名元素：代码注释风格) ─────────── */
.section-label {
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--accent);
  letter-spacing: .08em;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}
.section-title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -.02em;
  color: var(--primary);
  margin-bottom: 24px;
}

/* ─── About ───────────────────────────────────────────── */
.about-body p {
  font-size: .97rem;
  color: var(--secondary);
  line-height: 1.85;
  margin-bottom: 14px;
}
.about-body p:last-child { margin-bottom: 0; }
.about-body strong { color: var(--primary); font-weight: 600; }

/* ─── Education Timeline ──────────────────────────────── */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
  position: relative;
  padding-left: 28px;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(to bottom, var(--accent), var(--border));
}
.timeline-item {
  position: relative;
  padding: 0 0 28px 20px;
}
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot {
  position: absolute;
  left: -22px;
  top: 6px;
  width: 13px; height: 13px;
  border-radius: 50%;
  background: var(--surface);
  border: 2px solid var(--accent);
  z-index: 1;
}
.timeline-item.current .timeline-dot {
  background: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-light);
}
.timeline-period {
  font-family: var(--font-mono);
  font-size: .72rem;
  color: var(--muted);
  letter-spacing: .05em;
  margin-bottom: 4px;
}
.timeline-institution {
  font-size: .97rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 2px;
}
.timeline-degree {
  font-size: .88rem;
  color: var(--secondary);
}
.timeline-badge {
  display: inline-block;
  margin-top: 6px;
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  padding: 3px 9px;
  border-radius: 100px;
  background: var(--accent-light);
  color: var(--accent);
}

/* ─── Projects Grid ───────────────────────────────────── */
.projects-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  transition: border-color .2s, box-shadow .2s, transform .2s;
  display: flex;
  flex-direction: column;
}
.project-card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 20px rgba(29,78,216,.09);
  transform: translateY(-2px);
}
.project-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 10px;
  gap: 8px;
}
.project-name {
  font-size: .97rem;
  font-weight: 600;
  color: var(--primary);
  font-family: var(--font-mono);
  letter-spacing: -.01em;
}
.project-link-icon {
  flex-shrink: 0;
  color: var(--muted);
  transition: color .15s;
  margin-top: 1px;
}
.project-card:hover .project-link-icon { color: var(--accent); }
.project-desc {
  font-size: .85rem;
  color: var(--secondary);
  line-height: 1.7;
  flex: 1;
  margin-bottom: 14px;
}
.project-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.project-stars {
  font-size: .75rem;
  font-family: var(--font-mono);
  color: var(--accent-warm);
  display: flex;
  align-items: center;
  gap: 3px;
}
.tag-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}
.chip {
  font-size: .68rem;
  font-weight: 500;
  letter-spacing: .04em;
  padding: 2px 8px;
  border-radius: 100px;
  background: var(--surface-2);
  color: var(--secondary);
  border: 1px solid var(--border);
}

/* ─── Publications ────────────────────────────────────── */
.pub-doi {
  font-family: var(--font-mono);
  font-size: .7rem;
  color: var(--muted);
  letter-spacing: .02em;
}
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.pub-item {
  display: flex;
  gap: 16px;
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color .2s;
  text-decoration: none;
  color: inherit;
}
.pub-item:hover { border-color: var(--accent); }
a.pub-item:hover .pub-title { color: var(--accent); }
.pub-index {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--muted);
  padding-top: 2px;
  width: 24px;
}
.pub-body {}
.pub-title {
  font-size: .93rem;
  font-weight: 600;
  color: var(--primary);
  line-height: 1.5;
  margin-bottom: 6px;
}
.pub-venue {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-light);
  padding: 2px 10px;
  border-radius: 100px;
}

/* ─── Awards ──────────────────────────────────────────── */
.award-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.award-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 14px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color .2s;
}
.award-item:hover { border-color: var(--border-dark); }
.award-medal {
  flex-shrink: 0;
  font-size: 1.3rem;
  line-height: 1;
  margin-top: 1px;
}
.award-body {}
.award-name {
  font-size: .93rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 2px;
}
.award-detail {
  font-size: .82rem;
  color: var(--secondary);
}
.award-tier {
  display: inline-flex;
  align-items: center;
  margin-left: 6px;
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 100px;
}
.tier-gold   { background: var(--warm-light); color: var(--accent-warm); }
.tier-silver { background: #F1F5F9; color: #475569; }
.tier-bronze { background: #FEF9EE; color: #92400E; }

/* ─── Contact ─────────────────────────────────────────── */
.contact-body {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: .9rem;
  color: var(--secondary);
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  transition: all .15s;
  width: fit-content;
}
.contact-link:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-light);
}
.contact-note {
  font-size: .82rem;
  color: var(--muted);
  margin-top: 6px;
  font-family: var(--font-mono);
}

/* ─── Footer ──────────────────────────────────────────── */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--border);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}
.footer-copy {
  font-size: .78rem;
  color: var(--muted);
  font-family: var(--font-mono);
}
.footer-links {
  display: flex;
  gap: 16px;
}
.footer-links a {
  font-size: .78rem;
  color: var(--muted);
  transition: color .15s;
}
.footer-links a:hover { color: var(--accent); }

/* ─── Project Deploy Links ────────────────────────────── */
.project-deploy-links {
  display: flex;
  gap: 8px;
  margin-top: 14px;
  flex-wrap: wrap;
}
.deploy-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: .75rem;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--accent);
  color: var(--accent);
  background: var(--accent-light);
  transition: all .15s;
}
.deploy-link:hover {
  background: var(--accent);
  color: #fff;
}
.deploy-link-dim {
  border-color: var(--border-dark);
  color: var(--secondary);
  background: var(--surface);
}
.deploy-link-dim:hover {
  border-color: var(--secondary);
  color: var(--primary);
  background: var(--surface-2);
}

/* ─── Reveal ──────────────────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .55s ease, transform .55s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ─── Responsive ──────────────────────────────────────── */
@media (max-width: 640px) {
  .wrap { padding: 0 20px; }
  .hero-inner { flex-direction: column; gap: 20px; }
  .avatar { width: 72px; height: 72px; font-size: .95rem; }
  .projects-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .nav-toggle { display: flex; }
  .section { padding: 44px 0; }
  #hero { padding: 48px 0 40px; }
}

@media (prefers-reduced-motion: reduce) {
  .reveal { transition: none; opacity: 1; transform: none; }
}