/* ============================================================
   Yuqiu Liu — Personal Academic Website
   ============================================================ */

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:          #ffffff;
  --surface:     #f7f8fc;
  --text:        #1c1f2e;
  --text-2:      #5a6072;
  --accent:      #3451d1;
  --accent-bg:   #eef1fb;
  --border:      #e4e8f0;
  --tag-conf:    #1d6e3c;
  --tag-conf-bg: #e8f5ee;
  --tag-pre:     #7c4d11;
  --tag-pre-bg:  #fdf0e0;
  --radius:      8px;
  --shadow:      0 2px 12px rgba(0,0,0,.07);
  --max-w:       900px;
  --font:        'Inter', system-ui, -apple-system, sans-serif;
}

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

/* ---------- Nav ---------- */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -.3px;
  text-decoration: none;
}
.nav-brand:hover { text-decoration: none; color: var(--accent); }

.nav-links { display: flex; gap: 28px; }
.nav-links a {
  font-size: .9rem;
  font-weight: 500;
  color: var(--text-2);
  text-decoration: none;
  transition: color .2s;
}
.nav-links a:hover,
.nav-links a.active { color: var(--accent); }

/* ---------- Page Wrapper ---------- */
.page {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px 80px;
}

/* ---------- Profile Section ---------- */
.profile {
  display: flex;
  align-items: flex-start;
  gap: 48px;
  padding: 56px 0 40px;
}

.profile-photo {
  flex-shrink: 0;
  width: 160px;
  height: 210px;
  border-radius: 50%;
  overflow: hidden;
  border: 3px solid var(--border);
  box-shadow: var(--shadow);
}
.profile-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
}

.profile-info { flex: 1; padding-top: 4px; }

.profile-info h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -.5px;
  line-height: 1.2;
  margin-bottom: 4px;
}
.profile-info h1 .cn {
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--text-2);
  margin-left: 8px;
}

.profile-info .affil {
  font-size: .93rem;
  color: var(--text-2);
  margin-bottom: 16px;
}

.profile-info p {
  font-size: .94rem;
  color: var(--text);
  margin-bottom: 10px;
}

.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.social-links a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: .85rem;
  font-weight: 500;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 5px 14px;
  text-decoration: none;
  transition: all .2s;
}
.social-links a:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-bg);
  text-decoration: none;
}

/* ---------- Section ---------- */
.section { margin-top: 48px; }

.section-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -.3px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--border);
  margin-bottom: 24px;
}

/* ---------- News ---------- */
.news-list { display: flex; flex-direction: column; gap: 0; }

.news-item {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 9px 0;
  border-bottom: 1px solid var(--border);
  font-size: .9rem;
}
.news-item:last-child { border-bottom: none; }

.news-date {
  flex-shrink: 0;
  width: 72px;
  font-size: .8rem;
  font-weight: 600;
  color: var(--text-2);
  font-variant-numeric: tabular-nums;
}
.news-text { color: var(--text); line-height: 1.5; }
.news-text strong { font-weight: 600; }
.news-text a { color: var(--accent); }

/* ---------- Publications ---------- */
.pub-list { display: flex; flex-direction: column; gap: 28px; }

.pub-card {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.pub-thumb-wrap {
  flex-shrink: 0;
  width: 112px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
}

.pub-venue {
  display: inline-flex;
  align-items: center;
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .3px;
  padding: 2px 8px;
  border-radius: 4px;
  text-transform: uppercase;
  white-space: nowrap;
}
.venue-conf { color: var(--tag-conf); background: var(--tag-conf-bg); }
.venue-pre  { color: var(--tag-pre);  background: var(--tag-pre-bg); }

.pub-thumb {
  width: 112px;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--border);
}
.pub-thumb img {
  width: 100%;
  height: auto;
  display: block;
}

.pub-body { flex: 1; }

.pub-title {
  font-size: .97rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
  margin-bottom: 5px;
}
.pub-title a { color: var(--text); text-decoration: none; }
.pub-title a:hover { color: var(--accent); text-decoration: none; }

.pub-authors {
  font-size: .85rem;
  color: var(--text-2);
  margin-bottom: 4px;
  line-height: 1.5;
}
.pub-authors .me { font-weight: 600; color: var(--text); }
.section-note { font-size: .8rem; font-weight: 400; color: var(--text-2); margin-left: 10px; }


.pub-links { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }

.pub-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: .78rem;
  font-weight: 500;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 3px 10px;
  text-decoration: none;
  transition: all .18s;
}
.pub-link:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-bg);
  text-decoration: none;
}

/* view all pubs link */
.view-all {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 20px;
  font-size: .88rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
}
.view-all:hover { text-decoration: underline; }

/* ---------- Full Pub Page ---------- */
.pub-year-group { margin-bottom: 36px; }

.pub-year-label {
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text-2);
  margin-bottom: 16px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border);
}

/* ---------- Footer ---------- */
footer {
  margin-top: 60px;
  padding: 24px 0;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: .8rem;
  color: var(--text-2);
}

/* ---------- Responsive ---------- */
@media (max-width: 640px) {
  .profile {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 24px;
    padding: 36px 0 28px;
  }
  .social-links { justify-content: center; }
  .pub-card { flex-direction: column; }
  .pub-thumb-wrap { width: 100%; align-items: center; }
  .pub-thumb { width: 160px; height: auto; }
  .nav-links { gap: 16px; }
}