/* ============================================================
   集成与超构光子芯片实验室 - Main Stylesheet
   Inspired by PKU academic lab style, modern & professional
   ============================================================ */

@import url('https://fonts.loli.net/css2?family=Noto+Serif+SC:wght@300;400;600;700&family=EB+Garamond:ital,wght@0,400;0,600;1,400&family=Noto+Sans+SC:wght@300;400;500;700&family=Source+Serif+4:ital,opsz,wght@0,8..60,300;0,8..60,400;0,8..60,600;1,8..60,400&family=Playfair+Display:ital,wght@0,400;0,600;0,700;1,400;1,600;1,700&family=Courier+Prime:wght@400;700&family=Ma+Shan+Zheng&display=swap');

:root {
  --navy:      #0d2f5e;
  --navy-mid:  #174080;
  --blue:      #1e5fad;
  --blue-light:#2d7dd2;
  --gold:      #c8973a;
  --gold-light:#e8b45a;
  --bg:        #f8f7f4;
  --bg-card:   #ffffff;
  --text:      #1a1a2e;
  --text-mid:  #3a3a5c;
  --text-light:#6b7080;
  --border:    #dde2ec;
  --border-light: #eef1f8;
  --shadow-sm: 0 2px 8px rgba(13,47,94,0.08);
  --shadow-md: 0 4px 20px rgba(13,47,94,0.12);
  --shadow-lg: 0 8px 40px rgba(13,47,94,0.16);
  --radius:    6px;
  --radius-lg: 12px;
  --transition: 0.25s ease;
}

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

html { scroll-behavior: smooth; font-size: 17px; }

body {
  font-family: 'Noto Sans SC', 'Source Serif 4', serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ---- Typography ---- */
h1, h2, h3, h4, h5 {
  font-family: 'Noto Serif SC', 'EB Garamond', serif;
  line-height: 1.3;
  color: var(--navy);
  font-weight: 600;
}
a { color: var(--blue); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--blue-light); }

/* ================================================================
   TOP BANNER (University + Lab identity)
================================================================ */
#site-banner {
  background: #ffffff;
  padding: 0;
  position: relative;
  border-bottom: 1px solid var(--border-light);
}
.banner-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px 0 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  z-index: 1;
  overflow: visible;
}
.banner-identity {
  display: flex;
  align-items: center;
  gap: 32px;
  order: 2;
}
.banner-logo {
  width: auto;
  min-width: 180px;
  max-width: 250px;
  height: 140px;
  border-radius: 0;
  background: transparent;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-left: 0;
}
.banner-logo img {
  width: auto;
  height: 100%;
  object-fit: contain;
  display: block;
  max-width: 100%;
}
.banner-divider {
  width: 1.5px;
  height: 100px;
  background: rgba(13,47,94,0.2);
  flex-shrink: 0;
}
.banner-text-content {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
}
.banner-title {
  display: block;
  font-family: 'Ma Shan Zheng', 'STXingkai', 'Noto Serif SC', serif;
  font-size: 2.0rem;
  font-weight: 400;
  color: var(--navy);
  letter-spacing: 0.08em;
  line-height: 1.3;
}
.banner-title.en-text {
  font-family: 'Ma Shan Zheng', 'STXingkai', 'Noto Serif SC', serif;
  font-size: 2.1rem;
  font-weight: 400;
  letter-spacing: 0.03em;
}
.banner-subtitle {
  display: block;
  font-family: 'Ma Shan Zheng', 'STXingkai', 'Noto Serif SC', serif;
  font-size: 1.4rem;
  color: var(--blue);
  letter-spacing: 0.03em;
  font-weight: 400;
}
.banner-actions {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 28px;
  order: 1;
}
.banner-lablogo-stack {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
}
.banner-lablogo-img {
  height: 58px;
  width: auto;
  display: block;
}
.banner-slogan-img {
  height: 17px;
  width: auto;
  display: block;
  filter: brightness(0.25);
}
.whu-logo {
  height: 110px;
  width: auto;
  object-fit: contain;
}
.lang-switcher {
  display: flex;
  gap: 0;
  align-items: center;
  margin-left: auto;
  margin-right: 0;
}
.lang-btn {
  background: transparent;
  border: none;
  color: var(--text-light);
  padding: 6px 12px;
  border-radius: 0;
  font-size: 0.8rem;
  font-weight: 400;
  cursor: pointer;
  transition: all var(--transition);
  font-family: 'Noto Sans SC', sans-serif;
  letter-spacing: 0.05em;
  border-right: 1px solid var(--border);
}
.lang-btn:last-child {
  border-right: none;
}
.lang-btn.active {
  background: transparent;
  color: var(--blue);
  font-weight: 600;
  border-radius: 0;
  padding: 6px 12px;
}
.lang-btn:hover:not(.active) {
  color: var(--text-mid);
}

/* ================================================================
   NAVIGATION BAR
================================================================ */
#site-nav {
  background: var(--bg-card);
  border-bottom: 2px solid var(--navy);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  align-items: center;
}
.nav-links {
  display: flex;
  align-items: center;
  flex: 1;
}
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px 4px;
  margin-left: auto;
}
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--navy);
  border-radius: 2px;
  transition: all 0.3s;
}
.nav-hamburger.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.active span:nth-child(2) { opacity: 0; }
.nav-hamburger.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.nav-inner a {
  display: inline-block;
  padding: 14px 20px;
  font-family: 'Noto Sans SC', sans-serif;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-mid);
  letter-spacing: 0.04em;
  position: relative;
  transition: color var(--transition);
  white-space: nowrap;
}
.nav-inner a:hover {
  color: #0b3f80;
}
.nav-inner a.active {
  color: #0b3f80;
  font-weight: 600;
}
.nav-logo-link {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  margin-right: 4px;
  padding: 8px 10px 8px 0;
  text-decoration: none !important;
  border-bottom: none !important;
}
.nav-logo-link::after { display: none !important; }
.nav-lablogo {
  height: 30px;
  width: auto;
  display: block;
}
.nav-right-group {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.nav-slogan-img {
  height: 15px;
  width: auto;
  display: block;
  opacity: 0.72;
}

/* ================================================================
   PAGE LAYOUT
================================================================ */
#page-wrap {
  max-width: 1200px;
  margin: 0 auto;
  padding: 36px 32px 60px;
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 36px;
  align-items: start;
}
#page-wrap.no-sidebar {
  grid-template-columns: 1fr;
}
.main-col { min-width: 0; }
.side-col { min-width: 0; }

/* ================================================================
   SECTION TITLES
================================================================ */
.section-title {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}
.section-title h2 {
  font-size: 1.25rem;
  color: var(--navy);
}
.section-title .dot { display: none; }

/* ================================================================
   HOME: HERO / PI INTRODUCTION
================================================================ */
.hero-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: 32px;
  display: flex;
  gap: 28px;
  align-items: flex-start;
  margin-bottom: 28px;
}
.pi-photo {
  width: 200px;
  height: 240px;
  border-radius: var(--radius);
  object-fit: cover;
  flex-shrink: 0;
  background: linear-gradient(135deg, var(--border) 0%, var(--border-light) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-light);
  font-size: 0.75rem;
  text-align: center;
  border: 1px solid var(--border);
  overflow: hidden;
}
.pi-photo img { width: 100%; height: 100%; object-fit: cover; }
.pi-info h1 {
  font-size: 1.6rem;
  margin-bottom: 4px;
}
.pi-title-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--navy);
  color: #fff;
  font-size: 0.75rem;
  padding: 3px 12px;
  border-radius: 20px;
  margin-bottom: 14px;
  font-family: 'Noto Sans SC', sans-serif;
  letter-spacing: 0.05em;
}
.pi-bio {
  font-size: 0.93rem;
  color: var(--text-mid);
  line-height: 1.9;
}
.pi-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}
.pi-tag {
  background: var(--border-light);
  border: 1px solid var(--border);
  color: var(--navy-mid);
  font-size: 0.75rem;
  padding: 4px 12px;
  border-radius: 16px;
  font-family: 'Noto Sans SC', sans-serif;
  letter-spacing: 0.03em;
}
.pi-contact {
  margin-top: 14px;
  font-size: 0.85rem;
  color: var(--text-light);
}
.pi-contact a { color: var(--blue); }

/* ================================================================
   RESEARCH HIGHLIGHTS (Home)
================================================================ */
.section-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 28px 32px;
  margin-bottom: 24px;
}
.lab-slogan {
  font-style: italic;
  color: var(--text-light);
  font-size: 0.88rem;
  text-align: center;
  margin-top: 14px;
  margin-bottom: 0;
  letter-spacing: 0.04em;
}
.research-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 16px;
}
.research-item {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  transition: all var(--transition);
  cursor: default;
}
.research-item:hover {
  border-color: var(--blue);
  box-shadow: var(--shadow-sm);
  transform: translateY(-2px);
}
.research-item .ri-icon {
  font-size: 1.6rem;
  margin-bottom: 8px;
  display: block;
}
.research-item h4 {
  font-size: 0.92rem;
  color: var(--navy);
  margin-bottom: 6px;
}
.research-item p {
  font-size: 0.8rem;
  color: var(--text-light);
  line-height: 1.7;
}

/* ================================================================
   NEWS LIST
================================================================ */
.news-list { list-style: none; }
.news-list li {
  display: flex;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border-light);
  align-items: flex-start;
}
.news-list li:last-child { border-bottom: none; }
.news-date {
  flex-shrink: 0;
  min-width: 104px;
  color: var(--text-light);
  font-size: 0.79rem;
  padding-top: 4px;
  white-space: nowrap;
  letter-spacing: 0.01em;
}
.news-date .nd-month {
  display: inline;
  font-size: inherit;
  opacity: 1;
  letter-spacing: inherit;
  text-transform: capitalize;
}
.news-date .nd-day {
  display: inline;
  font-size: inherit;
  font-weight: normal;
  font-family: inherit;
  line-height: inherit;
}
.news-date .nd-day::before { content: " "; }
.news-date .nd-day::after  { content: ","; }
.news-date .nd-year {
  display: inline;
  font-size: inherit;
  opacity: 1;
  margin-top: 0;
  letter-spacing: inherit;
}
.news-date .nd-year::before { content: " "; }
.news-content .nc-tag { display: none; }
.news-content p { font-size: 0.88rem; color: var(--text-mid); line-height: 1.6; }

/* ================================================================
   SIDEBAR
================================================================ */
.sidebar-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 22px;
  margin-bottom: 20px;
}
.sidebar-card h3 {
  font-size: 0.95rem;
  margin-bottom: 14px;
  color: var(--navy);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-light);
}
.sidebar-stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 4px;
}
.stat-box {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
  text-align: center;
}
.stat-box .sb-num {
  display: block;
  font-family: 'EB Garamond', serif;
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--blue);
  line-height: 1;
}
.stat-box .sb-label {
  display: block;
  font-size: 0.7rem;
  color: var(--text-light);
  margin-top: 4px;
  letter-spacing: 0.04em;
}
.quick-links { list-style: none; }
.quick-links li {
  border-bottom: 1px solid var(--border-light);
}
.quick-links li:last-child { border-bottom: none; }
.quick-links a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 4px;
  font-size: 0.85rem;
  color: var(--text-mid);
  transition: all var(--transition);
}
.quick-links a:hover { color: var(--blue); padding-left: 8px; }
.quick-links a::after { content: '›'; font-size: 1.1rem; color: var(--gold); }

/* ================================================================
   MEMBERS PAGE
================================================================ */
.members-section { margin-bottom: 36px; }
.members-section h3 {
  font-size: 1.05rem;
  color: var(--navy-mid);
  margin-bottom: 16px;
  padding: 8px 0;
}
.members-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 20px;
}
.member-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 22px 16px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}
.member-card:hover {
  border-color: var(--blue);
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}
.member-photo {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  margin: 0 auto 12px;
  background: linear-gradient(135deg, var(--border) 0%, var(--border-light) 100%);
  border: 2px solid var(--border);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.member-photo img { width: 100%; height: 100%; object-fit: cover; }
.member-photo .mp-initials {
  font-family: 'EB Garamond', serif;
  font-size: 1.4rem;
  color: var(--text-light);
}
.member-card h4 { font-size: 0.95rem; margin-bottom: 4px; }
.member-card .mc-role {
  font-size: 0.75rem;
  color: var(--blue);
  font-family: 'Noto Sans SC', sans-serif;
  margin-bottom: 6px;
}
.member-card .mc-research {
  font-size: 0.72rem;
  color: var(--text-light);
  line-height: 1.5;
}

/* ================================================================
   PUBLICATIONS PAGE
================================================================ */
.pub-filters {
  display: flex;
  gap: 0;
  flex-wrap: nowrap;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  margin-bottom: 32px;
}
.pub-filters::-webkit-scrollbar { display: none; }
.pub-filter-btn {
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  margin-bottom: 0;
  padding: 10px 18px;
  font-family: 'Noto Serif SC', 'EB Garamond', serif;
  font-size: 0.87rem;
  font-weight: 600;
  color: var(--text-light);
  cursor: pointer;
  white-space: nowrap;
  letter-spacing: 0.01em;
  transition: color var(--transition), border-color var(--transition);
}
.pub-filter-btn:hover { color: var(--navy); }
.pub-filter-btn.active {
  color: var(--navy);
  border-bottom-color: var(--navy);
}
.pub-year-group { margin-bottom: 32px; }
.pub-year-label {
  font-family: 'EB Garamond', serif;
  font-size: 1.6rem;
  color: var(--gold);
  font-weight: 600;
  border-bottom: 1px solid var(--border);
  padding-bottom: 6px;
  margin-bottom: 16px;
}
.pub-item {
  display: flex;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border-light);
  align-items: flex-start;
}
.pub-item:last-child { border-bottom: none; }
.pub-thumb {
  flex-shrink: 0;
  width: 120px;
  align-self: flex-start;
  margin-top: 2px;
}
.pub-thumb img {
  width: 120px;
  display: block;
  border-radius: 4px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s;
}
.pub-thumb img:hover { box-shadow: var(--shadow-md); }
@media (max-width: 640px) { .pub-thumb { display: none; } }
.pub-num {
  flex-shrink: 0;
  min-width: 40px;
  color: var(--navy);
  font-size: 0.86rem;
  font-family: 'EB Garamond', serif;
  font-weight: 600;
  line-height: 1.5;
  margin-top: 1px;
  text-align: right;
}
.pub-body .pub-title {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.5;
  margin-bottom: 4px;
}
.pub-body .pub-authors {
  font-size: 0.82rem;
  color: var(--text-mid);
  margin-bottom: 4px;
}
.pub-body .pub-journal {
  font-style: normal;
  color: #174080;
  font-size: 0.82rem;
  font-family: inherit;
}
.pub-body .pub-journal a {
  color: inherit;
  text-decoration: none;
}
.pub-body .pub-journal a:hover {
  color: #0b3f80;
}
.pub-inline-links {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-left: 10px;
  font-size: 0.74rem;
  vertical-align: baseline;
}
.pub-body .pub-journal .pub-inline-links a,
.pub-body .pub-journal .pub-inline-links span {
  color: var(--text-light);
  font-weight: 500;
}
.pub-body .pub-journal .pub-inline-links a:hover {
  color: #0b3f80;
}
.pub-summary-wrap {
  margin-top: 7px;
}
.pub-summary-toggle {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.70rem;
  padding: 0;
  border: none;
  color: var(--blue);
  background: none;
  cursor: pointer;
  font-family: 'Noto Sans SC', sans-serif;
  font-weight: 500;
  letter-spacing: 0.03em;
  transition: opacity 0.15s;
  line-height: 1.6;
}
.pub-summary-toggle:hover {
  opacity: 0.7;
}
.pub-summary-toggle .ps-arrow {
  font-style: normal;
  font-size: 0.62rem;
  display: inline-block;
  transition: transform 0.2s;
}
.pub-summary-wrap.open .pub-summary-toggle .ps-arrow {
  transform: rotate(90deg);
}
.pub-body .pub-summary {
  display: none;
  font-size: 0.82rem;
  color: var(--text-mid);
  line-height: 1.65;
  margin-top: 7px;
  font-style: italic;
}
.pub-summary-wrap.open .pub-summary {
  display: block;
}
.pub-badges {
  display: flex;
  gap: 6px;
  margin-top: 8px;
  flex-wrap: wrap;
}
.pub-badge {
  font-size: 0.68rem;
  padding: 2px 8px;
  border-radius: 10px;
  font-weight: 500;
  letter-spacing: 0.03em;
}
.badge-journal { background: #e8f0fb; color: var(--blue); }
.badge-cover   { background: #fdf3e0; color: #b07000; }
.badge-highlight { background: #e8f7f0; color: #1a7a4a; }

/* ================================================================
   RESEARCH PAGE
================================================================ */
.research-topic {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
}
.research-topic h3 {
  font-size: 1.1rem;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.research-topic h3 .rt-num { display: none; }
.research-topic p {
  font-size: 0.9rem;
  color: var(--text-mid);
  line-height: 1.9;
  margin-bottom: 10px;
}
.research-topic .rt-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.rt-kw {
  font-size: 0.72rem;
  background: var(--border-light);
  color: var(--navy-mid);
  padding: 3px 10px;
  border-radius: 12px;
  font-family: 'Noto Sans SC', sans-serif;
}
.rt-gallery {
  margin: 20px 0 18px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 10px;
}
.rt-gallery img,
.rt-gallery video {
  width: 100%;
  height: 260px;
  object-fit: contain;
  background: var(--bg);
  display: block;
  border-radius: 6px;
  border: 1px solid var(--border);
}
.rt-fig {
  margin: 0;
  display: flex;
  flex-direction: column;
}
.rt-fig img,
.rt-fig video {
  flex: 1;
  height: 240px;
}
.rt-fig figcaption {
  font-size: 0.67rem;
  color: var(--text-light);
  text-align: center;
  padding: 4px 4px 0;
  font-style: italic;
  letter-spacing: 0.01em;
}
.pi-profile-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 10px 0 14px;
}
.pi-profile-links a {
  font-size: 0.78rem;
  color: var(--blue);
  text-decoration: none;
  transition: opacity 0.15s;
}
.pi-profile-links a:hover {
  text-decoration: underline;
  opacity: 0.8;
}
.pi-profile-links a svg { display: none; }
@media (max-width: 640px) {
  .rt-gallery { grid-template-columns: repeat(2, 1fr); }
}

/* ================================================================
   CONTACT PAGE
================================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.contact-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
}
.contact-info-item {
  display: flex;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border-light);
  align-items: flex-start;
}
.contact-info-item:last-child { border-bottom: none; }
.ci-icon {
  width: 22px;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  flex-shrink: 0;
  color: var(--text-light);
  margin-top: 3px;
}
.ci-icon svg { display: block; }
.ci-label { font-size: 0.72rem; color: var(--text-light); display: block; margin-bottom: 2px; }
.ci-value { font-size: 0.88rem; color: var(--text-mid); }

/* ================================================================
   JOIN US PAGE
================================================================ */
.join-section {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
}
.join-section h3 { font-size: 1.05rem; margin-bottom: 14px; }
.join-section ul {
  padding-left: 1.4em;
  color: var(--text-mid);
  font-size: 0.9rem;
  line-height: 2;
}

/* Borderless table layout for postdoc requirements */
.join-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 4px;
}
.join-table tr {
  border-top: 1px solid var(--border-light);
}
.join-table tr:last-child {
  border-bottom: 1px solid var(--border-light);
}
.jt-label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--navy);
  width: 90px;
  vertical-align: top;
  padding: 12px 18px 12px 0;
  white-space: nowrap;
}
.join-table td:last-child { padding: 8px 0; }
.join-table ul {
  margin: 0;
  padding-left: 1.2em;
  list-style: disc;
}
.join-table li {
  font-size: 0.88rem;
  color: var(--text-mid);
  line-height: 1.9;
}
.join-section p {
  font-size: 0.9rem;
  color: var(--text-mid);
  line-height: 1.9;
}
.highlight-box {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 22px 28px;
  margin-top: 28px;
  box-shadow: var(--shadow-sm);
}
.highlight-box p { color: var(--text-mid); font-size: 0.9rem; line-height: 2.0; }

/* ================================================================
   FOOTER
================================================================ */
#site-footer {
  background: #2a527a;
  color: rgba(255,255,255,0.65);
  padding: 12px 32px;
  text-align: center;
  font-size: 0.8rem;
  line-height: 2;
}
#site-footer a { color: var(--gold-light); }
#site-footer strong { color: rgba(255,255,255,0.9); }

/* ================================================================
   UTILITIES
================================================================ */
.btn-primary {
  display: inline-block;
  background: var(--blue);
  color: #fff;
  padding: 8px 22px;
  border-radius: 4px;
  font-size: 0.85rem;
  font-family: 'Noto Sans SC', sans-serif;
  transition: all var(--transition);
  border: none;
  cursor: pointer;
}
.btn-primary:hover {
  background: var(--navy);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}
.text-center { text-align: center; }
.mt-4 { margin-top: 16px; }
.mt-6 { margin-top: 24px; }

/* ================================================================
   LANGUAGE SWITCH
================================================================ */
[data-lang="en"] .cn-text,
[data-lang="en"] .cn-only { display: none !important; }
[data-lang="cn"] .en-text,
[data-lang="cn"] .en-only { display: none !important; }

/* ================================================================
   RESPONSIVE
================================================================ */

/* ── 900px ── */
@media (max-width: 900px) {
  #page-wrap { grid-template-columns: 1fr; padding: 24px 20px 40px; }
  .side-col { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
  .contact-grid { grid-template-columns: 1fr; }
  .banner-inner { padding: 0 20px; }
  .banner-identity { gap: 20px; }
  .banner-title { font-size: 1.5rem; }
  .banner-title.en-text { font-size: 1.7rem; }
}

/* ── 768px: hamburger nav ── */
@media (max-width: 768px) {
  /* Nav */
  .nav-hamburger { display: flex; }
  #site-nav { position: relative; }
  .nav-inner { padding: 0 16px; }
  .nav-links {
    display: none;
    flex-direction: column;
    align-items: stretch;
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    background: var(--bg-card);
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
    z-index: 200;
    border-top: 1px solid var(--border-light);
  }
  .nav-links.open { display: flex; }
  .nav-links a {
    padding: 13px 24px;
    border-bottom: 1px solid var(--border-light);
    font-size: 0.9rem;
    white-space: normal;
  }
  .nav-links .lang-switcher { margin-left: 0; padding: 10px 20px; }

  /* Banner */
  .banner-identity { gap: 14px; }
  .banner-logo { min-width: 70px; max-width: 110px; height: 80px; }
  .whu-logo { height: 64px; }
  .banner-divider { height: 52px; }
  .banner-title { font-size: 1.15rem; }
  .banner-title.en-text { font-size: 1.3rem; }
  .banner-subtitle { font-size: 0.88rem; }
  .banner-lablogo-img { height: 54px; }
  .banner-slogan-img { height: 14px; }
  .nav-slogan-img { display: none; }

  /* Slideshow */
  .hero-slideshow { height: 420px; }
}

/* ── 640px ── */
@media (max-width: 640px) {
  .home-research-grid { grid-template-columns: 1fr; }
  .rt-gallery { grid-template-columns: repeat(2, 1fr); }
  .pub-thumb { display: none; }
  /* PI card: stack vertically */
  .pi-card { flex-direction: column !important; align-items: center !important; text-align: center; }
  .pi-card .member-photo { width: 180px !important; height: 220px !important; align-self: center; }
}

/* ── 480px: very small phones ── */
@media (max-width: 480px) {
  .banner-logo { display: none; }
  .banner-divider { display: none; }
  .banner-title { font-size: 1.05rem; }
  .banner-title.en-text { font-size: 1.2rem; }
  .banner-inner { padding: 14px 16px; }
  .banner-lablogo-img { display: none; }
  .nav-lablogo { height: 26px; }
  .side-col { grid-template-columns: 1fr; }
  #page-wrap { padding: 16px 14px 36px; }
  .hero-slideshow { height: 260px; }
}

/* ================================================================
   HERO SLIDESHOW
================================================================ */
.hero-slideshow {
  position: relative;
  width: 100%;
  height: 600px;
  overflow: hidden;
  background: #050d1a;
}
@media (max-width: 768px) { .hero-slideshow { height: 500; } }
.hs-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 1s ease;
  pointer-events: none;
}
.hs-slide.active { opacity: 1; pointer-events: auto; }
.hs-bg { position: absolute; inset: 0; overflow: hidden; }
.hs-bg svg { width: 100%; height: 100%; display: block; }
.hs-caption {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  background: linear-gradient(transparent, rgba(3,9,24,0.92));
  padding: 50px 48px 24px;
  z-index: 5;
}
.hs-caption h2 {
  font-family: 'EB Garamond', 'Noto Serif SC', serif;
  font-size: 1.3rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 4px;
  line-height: 1.3;
}
.hs-caption p {
  font-size: 0.87rem;
  color: rgba(255,255,255,0.78);
}
.hs-desc-link {
  color: rgba(255,255,255,0.78);
  text-decoration: none;
  transition: color 0.2s;
  cursor: pointer;
}
.hs-desc-link:hover {
  color: #fff;
}
.hs-dots {
  position: absolute;
  bottom: 18px;
  right: 24px;
  display: flex;
  gap: 6px;
  z-index: 10;
}
.hs-dots button {
  width: 6px; height: 6px;
  border-radius: 3px;
  border: none;
  background: rgba(255,255,255,0.35);
  cursor: pointer;
  padding: 0;
  transition: all 0.3s;
}
.hs-dots button.active { background: #fff; width: 16px; }

/* ================================================================
   HOME PAGE: Research Cards Grid (full-width, no sidebar)
================================================================ */
.home-research-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 28px;
}
@media (max-width: 640px) { .home-research-grid { grid-template-columns: 1fr; } }
.home-rc {
  background: var(--bg-card);
  overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s;
}
.home-rc:hover {
  transform: scale(1.015);
  z-index: 2;
  box-shadow: var(--shadow-md);
}
.home-rc-img {
  height: 160px;
  overflow: hidden;
  position: relative;
}
.home-rc-img svg { width: 100%; height: 100%; display: block; }
.home-rc-body { padding: 18px 20px 22px; }
.home-rc-body h3 {
  font-family: 'EB Garamond', 'Noto Serif SC', serif;
  font-size: 1rem;
  color: var(--navy);
  margin-bottom: 6px;
  font-weight: 600;
}
.home-rc-body p {
  font-size: 0.82rem;
  color: var(--text-mid);
  line-height: 1.7;
}
.rc-tags { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 8px; }
.rc-tag {
  font-size: 0.68rem;
  color: var(--text-light);
}
.rc-papers { margin-top: 10px; display: flex; flex-direction: column; gap: 3px; }
.rc-papers a {
  font-size: 0.9rem;
  color: var(--text-dark);
  background: none;
  padding: 0;
  border: none;
  border-radius: 0;
  text-decoration: none;
  transition: color 0.15s;
}
.rc-papers a:hover { color: var(--blue); text-decoration: underline; }

/* Research page: slideshow then existing content */
.research-slideshow-wrap { margin-bottom: 0; }

/* ================================================================
   PHOTO WALL (Members page)
================================================================ */
.photo-wall-section {
  margin-top: 36px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}
.photo-wall-section h3 {
  font-size: 1rem;
  color: var(--navy);
  margin-bottom: 16px;
  padding: 6px 0;
}
.photo-wall {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}
@media (max-width: 640px) { .photo-wall { grid-template-columns: 1fr 1fr; } }
.pw-frame {
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 4/3;
  background: linear-gradient(135deg, #e2ecf6, #cdddf0);
  border: 1px solid var(--border);
  position: relative;
}
.pw-frame img {
  width: 100%; height: 100%;
  object-fit: cover;
  display: block;
}
.pw-placeholder {
  width: 100%; height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 7px;
  color: var(--text-light);
  font-size: 0.75rem;
  text-align: center;
  padding: 12px;
}
.pw-placeholder svg { opacity: 0.4; }
.pw-add {
  border: 1px dashed var(--gold);
  background: #fffbf0;
  color: var(--gold);
}
.pw-add svg { opacity: 0.6; }

/* ================================================================
   PUBLICATIONS: Selected, Conferences, Patents
================================================================ */
.selected-pubs-box {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 6px 28px 16px;
  margin-bottom: 28px;
  box-shadow: var(--shadow-sm);
}
.pub-num.reverse { color: var(--gold); }

.pub-section-title {
  font-family: 'EB Garamond', 'Noto Serif SC', serif;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--gold);
  border-bottom: 1px solid var(--border);
  padding-bottom: 6px;
  margin: 28px 0 14px;
}
.conf-item, .patent-item {
  display: flex;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border-light);
  align-items: flex-start;
}
.conf-item:last-child, .patent-item:last-child { border-bottom: none; }
.pub-num.conf { color: #4a6a9a; }
.pub-num.patent { color: #2a7a4a; }

/* ================================================================
   CONTACT: Google Maps embed
================================================================ */
.map-embed-wrap {
  margin-top: 20px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.map-embed-wrap iframe {
  width: 100%;
  height: 340px;
  display: block;
  border: none;
}
.map-caption {
  background: var(--bg-card);
  padding: 10px 18px;
  font-size: 0.82rem;
  color: var(--text-light);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

/* ================================================================
   IMAGE-BASED SLIDES — object-fit handles any aspect ratio
================================================================ */
.hs-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;       /* crops to fill, never distorts */
  object-position: center;
  display: block;
}
/* SVG fallback still works alongside */
.hs-bg svg {
  width: 100%;
  height: 100%;
  display: block;
}

/* ================================================================
   IMAGE-BASED RESEARCH CARDS
================================================================ */
.home-rc-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
  transition: transform 0.4s ease;
}
.home-rc:hover .home-rc-img img {
  transform: scale(1.04);
}

/* ================================================================
   LOGO IMAGE — any square/circle image works
================================================================ */
.banner-logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;     /* show full logo, no cropping */
  border-radius: 50%;
  display: block;
}

/* ================================================================
   RESEARCH PAGE — SUB-NAV TABS
================================================================ */
.research-subnav {
  display: flex;
  gap: 0;
  margin-bottom: 32px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.research-subnav::-webkit-scrollbar { display: none; }

.rst-btn {
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  margin-bottom: 0;
  padding: 10px 22px;
  font-family: 'Noto Serif SC', 'EB Garamond', serif;
  font-size: 0.87rem;
  font-weight: 600;
  color: var(--text-light);
  cursor: pointer;
  white-space: nowrap;
  letter-spacing: 0.01em;
  transition: color var(--transition), border-color var(--transition);
}
.rst-btn:hover { color: var(--navy); }
.rst-btn.active {
  color: var(--navy);
  border-bottom-color: var(--navy);
}

.rst-panel { display: none; }
.rst-panel.active { display: block; }

/* Overview — 4 direction summary cards */
.ov-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin-top: 24px;
}
@media (max-width: 600px) {
  .ov-grid { grid-template-columns: 1fr; }
}
.ov-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  cursor: pointer;
  transition: box-shadow var(--transition), transform var(--transition);
}
.ov-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.ov-card h4 {
  font-size: 0.88rem;
  color: var(--navy);
  margin-bottom: 8px;
}
.ov-card p {
  font-size: 0.80rem;
  color: var(--text-mid);
  line-height: 1.65;
}

/* ================================================================
   PUBLICATIONS PAGE — YEAR FILTER SIDEBAR
================================================================ */
#page-wrap.has-year-filter {
  grid-template-columns: 1fr 118px;
}

.pyf-wrap {
  position: sticky;
  top: 72px;
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.pyf-title {
  font-family: 'Noto Serif SC', 'EB Garamond', serif;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-light);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 6px;
  padding-bottom: 7px;
  border-bottom: 1px solid var(--border);
}

.pyf-btn {
  display: block;
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 7px 10px;
  font-size: 0.84rem;
  color: var(--text-mid);
  text-align: center;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.pyf-btn:hover {
  background: var(--border-light);
  color: var(--navy);
}
.pyf-btn.active {
  background: var(--navy);
  color: #fff;
  border-color: var(--navy);
  font-weight: 600;
}

@media (max-width: 768px) {
  #page-wrap.has-year-filter {
    grid-template-columns: 1fr;
  }
  .pyf-wrap {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 20px;
  }
  .pyf-btn { width: auto; }
}

/* Collaborators list */
.collab-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
}
.collab-list li {
  border-bottom: 1px solid var(--border-light);
  padding: 13px 4px;
}
.collab-list li:first-child { border-top: 1px solid var(--border-light); }
.collab-list li a {
  font-size: 0.92rem;
  color: var(--text);
  text-decoration: none;
  transition: color var(--transition);
}
.collab-list li a:hover { color: var(--blue); }

/* Placeholder panels (Facilities / Fundings) */
.rst-placeholder {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-light);
}
.rst-placeholder .rp-icon {
  font-size: 2.2rem;
  margin-bottom: 14px;
  opacity: 0.4;
}
.rst-placeholder p {
  font-size: 0.88rem;
  line-height: 1.8;
}

/* ================================================================
   PI PHOTO
================================================================ */
.pi-photo-wrap {
  width: 110px;
  height: 130px;
  border-radius: var(--radius);
  overflow: hidden;
  flex-shrink: 0;
  border: 1px solid var(--border);
  background: var(--border-light);
}
.pi-photo-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  display: block;
}

/* ================================================================
   MEMBER PHOTO — supports real image with initials fallback
================================================================ */
.member-photo {
  position: relative;
  overflow: hidden;
  background: var(--border-light);
  display: flex;
  align-items: center;
  justify-content: center;
}
.member-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;  /* favour face at top */
  display: block;
}
.member-photo img.photo-loaded + .mp-initials { display: none; }
/* when img fails to load, hide it and show initials */
.member-photo img.photo-error { display: none; }

.hidden { display: none !important; }