:root {
  --bg: #ffffff;
  --surface: #f6f7f9;
  --text: #1a1d21;
  --text-soft: #5b6470;
  --border: #e6e8eb;
  --accent: #2563eb;
  --accent-soft: #eaf0ff;
  --radius: 14px;
  --maxw: 820px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", Helvetica, Arial, sans-serif;
}

[data-theme="dark"] {
  --bg: #0f1216;
  --surface: #161a20;
  --text: #e8eaed;
  --text-soft: #9aa4b2;
  --border: #262b33;
  --accent: #60a5fa;
  --accent-soft: #17233b;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  transition: background .25s ease, color .25s ease;
}

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

.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: .9rem 1.4rem;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav__brand { font-weight: 700; color: var(--text); font-size: 1.05rem; }
.nav__links {
  display: flex;
  gap: 1.25rem;
  margin-left: auto;
  flex-wrap: wrap;
}
.nav__links a { color: var(--text-soft); font-size: .95rem; }
.nav__links a:hover { color: var(--accent); text-decoration: none; }
.nav__actions { display: flex; gap: .5rem; }

.btn-ghost {
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 8px;
  padding: .35rem .6rem;
  font-size: .85rem;
  line-height: 1;
  transition: background .2s, border-color .2s;
}
.btn-ghost:hover { border-color: var(--accent); background: var(--accent-soft); }

main { max-width: var(--maxw); margin: 0 auto; padding: 0 1.4rem; }

.section { padding: 2.6rem 0; border-top: 1px solid var(--border); }
.section h2 { font-size: 1.35rem; margin: 0 0 1.1rem; }
.section__text { color: var(--text-soft); margin: 0; }

.hero {
  display: flex;
  gap: 2rem;
  align-items: center;
  padding: 3rem 0 2.4rem;
  flex-wrap: wrap;
}
.hero__photo {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border);
  background: var(--surface);
  flex-shrink: 0;
}
.hero__intro { flex: 1; min-width: 260px; }
.hero__name { font-size: 2.1rem; margin: 0 0 .3rem; letter-spacing: -.02em; }
.hero__title { margin: 0 0 .2rem; font-weight: 600; color: var(--text); }
.hero__affil { margin: 0 0 .8rem; color: var(--text-soft); font-size: .95rem; }
.hero__bio { margin: 0 0 1.1rem; color: var(--text-soft); }

.hero__links { display: flex; gap: .55rem; flex-wrap: wrap; }
.hero__links a {
  border: 1px solid var(--border);
  background: var(--surface);
  padding: .4rem .8rem;
  border-radius: 999px;
  font-size: .88rem;
  color: var(--text);
  transition: background .2s, border-color .2s;
}
.hero__links a:hover { border-color: var(--accent); background: var(--accent-soft); text-decoration: none; }

.tags { list-style: none; display: flex; flex-wrap: wrap; gap: .55rem; padding: 0; margin: 0; }
.tags li {
  background: var(--accent-soft);
  color: var(--accent);
  padding: .35rem .8rem;
  border-radius: 999px;
  font-size: .9rem;
  font-weight: 500;
}

.pub {
  display: flex;
  gap: 1.2rem;
  align-items: flex-start;
  padding: 1.1rem 1.2rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 1rem;
  background: var(--surface);
}
.pub__thumb { flex: 0 0 240px; display: block; }
.pub__thumb img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  transition: border-color .2s, transform .2s;
}
.pub__thumb:hover img { border-color: var(--accent); transform: translateY(-2px); }
.pub__body { flex: 1 1 auto; min-width: 0; }
.pub__title { margin: 0 0 .3rem; font-size: 1.05rem; }
.pub__authors { margin: 0 0 .2rem; font-size: .92rem; color: var(--text-soft); }
.pub__venue { margin: 0 0 .5rem; font-size: .9rem; color: var(--text-soft); font-style: italic; }
.pub__actions { margin: 0; display: flex; gap: .8rem; font-size: .9rem; }

.timeline { display: flex; flex-direction: column; gap: 1.3rem; }
.timeline__item { display: flex; gap: 1.2rem; }
.timeline__date {
  flex-shrink: 0;
  width: 110px;
  color: var(--accent);
  font-weight: 600;
  font-size: .9rem;
  padding-top: .15rem;
}
.timeline__item h3 { margin: 0 0 .2rem; font-size: 1.02rem; }
.timeline__item p { margin: 0; color: var(--text-soft); font-size: .93rem; }

.contact__email { font-size: 1.1rem; margin-top: .6rem; }
.footer {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2rem 1.4rem 3rem;
  color: var(--text-soft);
  font-size: .85rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 640px) {
  .nav__links { display: none; }
  .hero { justify-content: center; text-align: center; }
  .hero__links { justify-content: center; }
  .pub { flex-direction: column; }
  .pub__thumb { flex: none; width: 100%; max-width: 360px; }
  .timeline__item { flex-direction: column; gap: .3rem; }
  .timeline__date { width: auto; }
}