:root{
  --primary:#0e6e5c;
  --primary-dark:#0a4f42;
  --primary-light:#e7f3f0;
  --accent:#c47f17;
  --ink:#1f2a2e;
  --muted:#5b6b70;
  --line:#dfe8e6;
  --bg:#f7faf9;
  --white:#ffffff;
  --radius:14px;
  --shadow:0 6px 24px rgba(14,110,92,.08);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC",sans-serif;
  color:var(--ink);background:var(--bg);line-height:1.75;font-size:16px;
}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;display:block}
.container{width:min(1120px,92%);margin:0 auto}

/* header */
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.nav-wrap{display:flex;align-items:center;justify-content:space-between;height:68px}
.brand{display:flex;align-items:center;gap:12px;color:var(--ink)}
.brand:hover{text-decoration:none}
.brand-mark{width:42px;height:42px;border-radius:10px;flex:none;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,var(--primary),var(--primary-dark));color:#fff;font-weight:700;font-size:20px}
.brand-text{display:flex;flex-direction:column;line-height:1.3}
.brand-text strong{font-size:16px}
.brand-text small{color:var(--muted);font-size:12px}
.site-nav{display:flex;gap:22px;align-items:center}
.site-nav a{color:var(--ink);font-size:15px}
.site-nav a:hover{color:var(--primary);text-decoration:none}
.lang-switch{border:1.5px solid var(--primary);color:var(--primary);border-radius:999px;padding:5px 14px;font-size:13px;font-weight:600}
.lang-switch:hover{background:var(--primary-light);text-decoration:none}
.nav-toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:8px}
.nav-toggle span{width:24px;height:2px;background:var(--ink);border-radius:2px}

/* hero */
.hero{background:radial-gradient(1200px 400px at 85% -10%,rgba(196,127,23,.14),transparent 60%),linear-gradient(160deg,var(--primary-dark),var(--primary) 55%,#138a72);color:#fff;padding:88px 0 72px}
.hero-kicker{letter-spacing:.12em;font-size:14px;opacity:.85;margin-bottom:14px}
.hero h1{font-size:clamp(28px,4.5vw,44px);line-height:1.25;font-weight:700;max-width:20em}
.hero-lead{max-width:46em;margin:20px 0 30px;opacity:.94}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}
.btn{display:inline-block;padding:12px 26px;border-radius:999px;font-size:15px;font-weight:600;transition:.2s}
.btn:hover{text-decoration:none;transform:translateY(-1px)}
.btn-primary{background:#fff;color:var(--primary-dark)}
.btn-primary:hover{background:var(--primary-light)}
.btn-ghost{border:1.5px solid rgba(255,255,255,.7);color:#fff}
.btn-ghost:hover{background:rgba(255,255,255,.12)}
.btn-light{background:var(--primary);color:#fff}
.hero-facts{list-style:none;display:flex;gap:40px;margin-top:44px;flex-wrap:wrap}
.hero-facts li{display:flex;flex-direction:column}
.hero-facts strong{font-size:30px;line-height:1.1}
.hero-facts span{font-size:13px;opacity:.85}

/* sections */
.section{padding:64px 0 8px}
.section-title{font-size:26px;color:var(--primary-dark);margin-bottom:28px;display:flex;align-items:center;gap:14px}
.section-title::before{content:"";width:8px;height:26px;border-radius:4px;background:linear-gradient(var(--primary),var(--accent))}

/* about */
.about-grid{display:grid;grid-template-columns:280px 1fr;gap:36px;align-items:start}
.about-pi h3{font-size:20px;color:var(--primary-dark)}
.about-pi .pi-sub{color:var(--muted);font-size:14px;margin-bottom:14px}
.photo-placeholder{aspect-ratio:3/4;border-radius:var(--radius);border:1.5px dashed #b8ccc7;background:var(--white);display:flex;flex-direction:column;gap:10px;align-items:center;justify-content:center;color:var(--muted)}
.photo-placeholder.sm{aspect-ratio:1;width:84px;border-radius:50%}
#about-paragraphs p{margin-bottom:14px;color:#31414a}
.about-note{color:var(--primary-dark);font-weight:600}

/* research cards */
.card-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
.card{background:var(--white);border:1px solid var(--line);border-radius:var(--radius);padding:26px 26px 22px;box-shadow:var(--shadow);transition:.2s}
.card:hover{transform:translateY(-3px);border-color:var(--primary)}
.card-icon{width:48px;height:48px;border-radius:12px;margin-bottom:16px;background:var(--primary-light);color:var(--primary);display:flex;align-items:center;justify-content:center}
.card h3{font-size:17px;color:var(--primary-dark);margin-bottom:8px}
.card p{color:var(--muted);font-size:14.5px}

/* publications */
.pub-meta{color:var(--muted);font-size:14px;margin:-14px 0 20px}
.pub-meta span{color:var(--accent);font-weight:700}
#pub-note[data-live="ok"]{color:var(--primary);font-weight:600}
.pub-list{list-style:none;display:grid;gap:14px}
.pub-item{background:var(--white);border:1px solid var(--line);border-left:4px solid var(--primary);border-radius:10px;padding:16px 20px}
.pub-journal{font-weight:700;font-style:italic;color:var(--primary-dark)}
.pub-year{color:var(--accent);font-weight:700;font-size:14px;margin-left:10px}
.pub-authors{color:#31414a;font-size:14px;margin-top:6px}
.pub-title{width:100%;color:var(--ink);font-weight:600;margin-top:2px}
.pub-cite{color:var(--muted);font-size:14px;margin-top:4px}
.pub-cite a{margin-right:4px}

/* timeline */
.timeline{position:relative;margin:6px 0 34px;padding-left:26px;border-left:2px solid var(--line)}
.tl-item{position:relative;margin-bottom:22px}
.tl-item::before{content:"";position:absolute;left:-33px;top:6px;width:12px;height:12px;border-radius:50%;background:var(--primary);border:3px solid var(--primary-light)}
.tl-time{font-size:13.5px;color:var(--accent);font-weight:700;letter-spacing:.03em}
.tl-body{display:flex;flex-direction:column}
.tl-body strong{color:var(--ink)}
.tl-body span{color:var(--muted);font-size:14.5px}
.service h3{font-size:17px;color:var(--primary-dark);margin-bottom:10px}
.service ul{list-style:none;display:grid;gap:8px}
.service li{padding-left:22px;position:relative;color:#31414a}
.service li::before{content:"";position:absolute;left:0;top:.62em;width:8px;height:8px;border-radius:2px;background:var(--accent)}

/* news */
.news-list{display:grid;gap:16px}
.news-item{background:var(--white);border:1px solid var(--line);border-radius:12px;padding:20px 24px;box-shadow:var(--shadow)}
.news-item time{color:var(--accent);font-size:13.5px;font-weight:700;letter-spacing:.04em}
.news-item h3{font-size:17px;color:var(--primary-dark);margin:6px 0 6px}
.news-item p{color:var(--muted);font-size:14.5px}
.news-link{display:inline-block;margin-top:8px;font-size:14px;font-weight:600}
.news-preview{margin-top:8px}

/* join */
.section-join{padding-bottom:72px}
.join-box{background:linear-gradient(150deg,var(--primary-dark),var(--primary));color:#fff;border-radius:18px;padding:38px 40px;box-shadow:var(--shadow)}
.join-pos{margin-bottom:16px}
.join-box h3{font-size:19px;margin-bottom:8px}
.join-box p{max-width:56em;opacity:.94}
.join-note{font-size:14px;opacity:.85;border-top:1px solid rgba(255,255,255,.25);padding-top:14px;margin-top:6px}
.join-actions{margin-top:22px}
.btn-light:hover{background:var(--primary-dark)}

/* team */
.pi-card{display:grid;grid-template-columns:240px 1fr;gap:30px;background:var(--white);border:1px solid var(--line);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow);margin-bottom:34px;align-items:center}
.pi-photo .photo-placeholder{aspect-ratio:3/4}
.pi-info h3{font-size:22px;color:var(--primary-dark);margin-bottom:4px}
.pi-info p{color:var(--muted);margin-top:10px}
.member-role{color:var(--accent);font-size:14px;font-weight:600}
.team-group{margin-bottom:30px}
.group-title{font-size:18px;color:var(--primary-dark);margin-bottom:14px;display:flex;align-items:center;gap:10px}
.group-count{background:var(--primary-light);color:var(--primary);border-radius:999px;font-size:12.5px;padding:2px 10px;font-weight:700}
.member-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px}
.member-card{background:var(--white);border:1px solid var(--line);border-radius:12px;padding:20px;display:flex;gap:16px;align-items:flex-start;box-shadow:var(--shadow)}
.member-card img{width:84px;height:84px;border-radius:50%;object-fit:cover;flex:none}
.member-card h4{font-size:16px;color:var(--ink)}
.member-card p{color:#31414a;font-size:13.5px;margin-top:5px;line-height:1.6}

/* footer */
.site-footer{background:var(--primary-dark);color:#d8e8e4}
.footer-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:30px;padding:48px 0}
.footer-grid h3{font-size:15px;color:#fff;margin-bottom:12px;letter-spacing:.05em}
.footer-grid p{font-size:14px;line-height:1.9}
.footer-grid a{color:#d8e8e4}
.footer-grid a:hover{color:#fff}
.footer-bar{border-top:1px solid rgba(255,255,255,.15);padding:16px 0;font-size:13px;opacity:.8}

@media (max-width:860px){
  .site-nav{position:absolute;top:68px;right:0;left:0;display:none;flex-direction:column;gap:0;background:#fff;border-bottom:1px solid var(--line);padding:8px 4%}
  .site-nav.open{display:flex}
  .site-nav a{padding:12px 0;border-top:1px solid var(--line)}
  .nav-toggle{display:flex}
  .about-grid{grid-template-columns:1fr}
  .card-grid{grid-template-columns:1fr}
  .pi-card{grid-template-columns:1fr}
  .pi-photo{max-width:280px}
  .footer-grid{grid-template-columns:1fr;gap:24px}
  .join-box{padding:28px 24px}
  .hero{padding:64px 0 56px}
  .hero-facts{gap:26px}
}

/* publications: year-collapsible groups */
.year-group{background:var(--white);border:1px solid var(--line);border-radius:12px;margin-bottom:14px;box-shadow:var(--shadow);overflow:hidden}
.year-head{display:flex;align-items:center;gap:14px;width:100%;padding:14px 20px;background:none;border:0;cursor:pointer;font:inherit;text-align:left}
.year-head:hover{background:var(--primary-light)}
.year-label{font-size:18px;font-weight:700;color:var(--primary-dark);min-width:4.2em}
.year-count{color:var(--muted);font-size:13px}
.year-toggle{margin-left:auto;width:28px;height:28px;flex:none;border-radius:50%;border:1.5px solid var(--primary);color:var(--primary);display:flex;align-items:center;justify-content:center}
.year-toggle::after{content:"+";font-size:18px;font-weight:700;line-height:1}
.year-group.open .year-toggle::after{content:"\2212"}
.year-body{padding:2px 14px 14px}
.year-body .pub-item{border-left:3px solid var(--primary-light)}
@media (max-width:860px){
  .year-head{padding:12px 14px}
  .year-label{font-size:16px}
  .year-body{padding:2px 8px 10px}
}

/* research figure */
.research-figure{margin-top:26px;background:var(--white);border:1px solid var(--line);border-radius:12px;padding:18px;box-shadow:var(--shadow)}
.research-figure img{width:100%;border-radius:8px;display:block}
.research-figure figcaption{text-align:center;color:var(--muted);font-size:14px;margin-top:12px}

/* courses & outreach */
.course-grid{display:grid;gap:20px}
.course-card{background:var(--white);border:1px solid var(--line);border-radius:12px;overflow:hidden;box-shadow:var(--shadow);display:grid;grid-template-columns:minmax(240px,380px) 1fr}
.course-card img{width:100%;height:100%;object-fit:cover;display:block}
.course-body{padding:22px 24px}
.course-body h3{font-size:17px;color:var(--primary-dark);margin-bottom:10px}
.course-body p{color:var(--muted);font-size:14.5px;margin-bottom:8px}
.course-cap{font-size:13px;color:var(--accent)}
.course-online .course-body{display:flex;flex-direction:column;align-items:flex-start;gap:4px}
@media (max-width:760px){
  .course-card{grid-template-columns:1fr}
  .course-card img{max-height:320px}
}

/* courses taught */
.course-names{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:6px}
.course-names span{background:var(--primary-light);color:var(--primary-dark);border-radius:999px;padding:10px 24px;font-weight:600;font-size:15px}

/* footer QR */
.footer-grid.four{grid-template-columns:repeat(4,1fr)}
@media (max-width:960px){.footer-grid.four{grid-template-columns:repeat(2,1fr)}}
@media (max-width:560px){.footer-grid.four{grid-template-columns:1fr}}
#contact-qr{display:flex;flex-wrap:wrap}
.footer-bar-inner{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:8px}
.course-card.no-img{grid-template-columns:1fr}
html[lang="en"] .section-title,html[lang="en"] .footer-grid h3,html[lang="en"] .group-title{text-transform:uppercase;letter-spacing:.03em}

/* publication metric buttons */
.pub-metrics{display:flex;gap:8px;flex-wrap:wrap;margin-top:8px}
.metric-btn{font-size:12px;border:1px solid var(--line);border-radius:999px;padding:2px 11px;background:var(--bg);color:var(--muted);line-height:1.7}
.metric-btn:hover{border-color:var(--primary);color:var(--primary);text-decoration:none}
.pub-pdf{border-color:var(--accent);color:var(--accent);font-weight:600}
.site-nav a{white-space:nowrap}
.site-nav{gap:18px}
.brand-mark{width:113px;height:38px;object-fit:contain;display:block;border-radius:0;background:none}