/* ===== Tang Lab — shared stylesheet ===== */
:root{
  --blue:#0a4b8c;        /* Xuanwu Hospital blue (primary) */
  --blue-d:#073a6e;      /* darker */
  --blue-l:#1c6bbd;      /* lighter accent */
  --sky:#e8f1fb;         /* tint */
  --ink:#1f2933;
  --muted:#5b6b7b;
  --line:#e2e8f0;
  --bg:#f6f9fc;
  --card:#ffffff;
  --maxw:1120px;
}
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{
  font-family:"Inter",-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  color:var(--ink);background:var(--bg);line-height:1.65;font-size:16px;-webkit-font-smoothing:antialiased;
}
a{color:var(--blue-l);text-decoration:none;}
a:hover{text-decoration:underline;}
img{max-width:100%;display:block;}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px;}

/* ---- Nav ---- */
.nav{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.95);backdrop-filter:blur(8px);border-bottom:1px solid var(--line);}
.nav .wrap{display:flex;align-items:center;gap:20px;height:64px;}
.nav .logo{font-weight:800;color:var(--blue);font-size:20px;letter-spacing:.2px;white-space:nowrap;}
.nav .logo span{color:var(--blue-l);}
.nav .menu{display:flex;gap:6px;margin-left:auto;flex-wrap:wrap;}
.nav .menu a{color:var(--muted);font-size:14.5px;font-weight:500;padding:8px 12px;border-radius:8px;}
.nav .menu a:hover{color:var(--blue);background:var(--sky);text-decoration:none;}
.nav .menu a.active{color:var(--blue);background:var(--sky);}
.nav .lang-toggle{margin-left:6px;border:1px solid var(--blue);background:none;color:var(--blue);font-size:13.5px;font-weight:600;padding:6px 12px;border-radius:8px;cursor:pointer;font-family:inherit;white-space:nowrap;}
.nav .lang-toggle:hover{background:var(--blue);color:#fff;}
.nav .burger{display:none;margin-left:auto;background:none;border:none;font-size:24px;color:var(--blue);cursor:pointer;}

/* ---- Hero ---- */
.hero{position:relative;color:#fff;overflow:hidden;}
.hero .bg{position:absolute;inset:0;background-size:cover;background-position:center;}
.hero .ov{position:absolute;inset:0;background:linear-gradient(120deg,rgba(7,58,110,.92),rgba(10,75,140,.78) 55%,rgba(28,107,189,.6));}
.hero .wrap{position:relative;z-index:2;padding:110px 24px 96px;}
.hero h1{font-size:42px;line-height:1.18;font-weight:800;max-width:880px;margin-bottom:18px;}
.hero p{font-size:18px;max-width:680px;opacity:.95;}
.hero p:has(.hero-sub-zh){max-width:none;}
.hero .hero-sub-zh{white-space:nowrap;}
@media(max-width:760px){.hero .hero-sub-zh{white-space:normal;}}
.hero .cta{margin-top:30px;display:flex;gap:14px;flex-wrap:wrap;}
.btn{display:inline-block;padding:12px 24px;border-radius:10px;font-weight:600;font-size:15px;cursor:pointer;border:1px solid transparent;}
.btn.primary{background:#fff;color:var(--blue);}
.btn.primary:hover{background:var(--sky);text-decoration:none;}
.btn.ghost{background:transparent;color:#fff;border-color:rgba(255,255,255,.6);}
.btn.ghost:hover{background:rgba(255,255,255,.12);text-decoration:none;}

/* ---- Page header (inner pages) ---- */
.phead{background:linear-gradient(120deg,var(--blue-d),var(--blue));color:#fff;padding:54px 24px 46px;}
.phead h1{font-size:34px;font-weight:800;}
.phead p{opacity:.9;margin-top:8px;max-width:760px;}

/* ---- Sections ---- */
section.block{padding:60px 0;}
.eyebrow{color:var(--blue-l);font-size:13px;font-weight:700;letter-spacing:1.6px;text-transform:uppercase;margin-bottom:10px;}
h2.title{font-size:28px;color:var(--blue-d);font-weight:800;margin-bottom:10px;}
.lead{color:var(--muted);margin-bottom:30px;font-size:17px;}
h3{color:var(--blue-d);font-size:20px;margin:26px 0 12px;}

/* ---- Grid & cards ---- */
.grid{display:grid;gap:20px;}
.g2{grid-template-columns:repeat(2,1fr);}
.g3{grid-template-columns:repeat(3,1fr);}
.g4{grid-template-columns:repeat(4,1fr);}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:24px;transition:transform .15s,box-shadow .15s;}
.card:hover{transform:translateY(-4px);box-shadow:0 14px 34px rgba(10,75,140,.10);}
.card .ic{width:48px;height:48px;border-radius:12px;background:var(--sky);color:var(--blue);display:flex;align-items:center;justify-content:center;font-size:24px;margin-bottom:14px;}
.card h4{color:var(--blue-d);font-size:18px;margin-bottom:8px;}
.card p{color:var(--muted);font-size:14.5px;}

/* ---- People ---- */
.people-group{margin-bottom:44px;}
.people-group h3{border-bottom:2px solid var(--sky);padding-bottom:8px;margin-bottom:22px;}
.person{background:var(--card);border:1px solid var(--line);border-radius:14px;overflow:hidden;transition:transform .15s,box-shadow .15s;}
.person:hover{transform:translateY(-4px);box-shadow:0 14px 34px rgba(10,75,140,.10);}
.person .ph-wrap{position:relative;width:100%;aspect-ratio:1/1;}
.person .ph{width:100%;height:100%;object-fit:cover;background:var(--sky);}
.person .ph-img{position:absolute;inset:0;}
.person .ph.ph-ph{display:flex;align-items:center;justify-content:center;color:var(--blue-l);font-size:46px;font-weight:700;}
.person .body{padding:16px;}
.person .nm{font-weight:700;color:var(--blue-d);font-size:16px;}
.person .ex{color:var(--muted);font-size:13.5px;margin:6px 0 10px;min-height:38px;}
.person .em{font-size:13px;word-break:break-all;}
/* structured multi-section experience (Faculty) */
.person .ex-sec{margin:8px 0;}
.person .ex-h{font-size:12.5px;font-weight:700;color:var(--blue);text-transform:uppercase;letter-spacing:.4px;margin-bottom:3px;}
.person .ex-list{margin:0 0 4px 16px;padding:0;color:var(--muted);font-size:13px;line-height:1.55;}
.person .ex-list li{margin-bottom:3px;}
/* horizontal layout for PI / Faculty: photo left, info right */
.grid-horizontal{display:grid;grid-template-columns:1fr;gap:20px;}
/* Faculty: two per row on wider screens */
@media(min-width:760px){.grid-horizontal{grid-template-columns:repeat(2,1fr);}}
/* PI: always full width (single column), overriding the 2-col rule above */
.grid-horizontal.grid-pi{grid-template-columns:1fr;}
/* PI + Faculty share one uniform card height; long content scrolls inside */
.person.horizontal{display:grid;grid-template-columns:200px 1fr;height:300px;}
.person.horizontal .ph-wrap{aspect-ratio:auto;height:300px;}
.person.horizontal .body{padding:20px 22px;display:flex;flex-direction:column;justify-content:center;overflow-y:auto;}
.person.horizontal .nm{font-size:18px;}
.person.horizontal .ex{font-size:14px;min-height:auto;margin:8px 0 10px;}
@media(max-width:460px){
  .person.horizontal{grid-template-columns:1fr;height:auto;}
  .person.horizontal .ph-wrap{aspect-ratio:1/1;height:auto;}
  .person.horizontal .body{overflow:visible;}
}

/* ---- PI / About ---- */
.pi-card{display:grid;grid-template-columns:260px 1fr;gap:30px;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:28px;}
.pi-card img{width:100%;border-radius:12px;}
.pi-card .name{font-size:26px;font-weight:800;color:var(--blue-d);}
.pi-card .ti{color:var(--blue-l);font-weight:600;margin:4px 0;}
.pi-card .meta{color:var(--muted);font-size:14.5px;margin-top:6px;}
.pi-card .bio{margin-top:14px;color:var(--ink);}
.timeline{list-style:none;border-left:2px solid var(--sky);margin:6px 0 6px 8px;padding-left:22px;}
.timeline li{position:relative;margin-bottom:14px;}
.timeline li::before{content:"";position:absolute;left:-29px;top:7px;width:10px;height:10px;border-radius:50%;background:var(--blue-l);border:3px solid var(--bg);}
.timeline .per{font-weight:700;color:var(--blue);font-size:14px;}
.timeline .det{color:var(--muted);font-size:14.5px;}
@media(max-width:620px){.pi-card{grid-template-columns:1fr;}}

/* ---- Publications ---- */
.scholar-banner{display:flex;gap:12px;align-items:flex-start;background:var(--sky);border:1px solid #cfe2f6;border-radius:12px;padding:14px 18px;margin-bottom:22px;font-size:14.5px;color:var(--blue-d);line-height:1.6;}
.scholar-banner .si{font-size:18px;line-height:1.4;}
.scholar-banner a{font-weight:700;}
.pub-tools{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:24px;align-items:center;}
.pub-tools input,.pub-tools select{padding:10px 14px;border:1px solid var(--line);border-radius:10px;font-size:14.5px;font-family:inherit;}
.pub-tools input{flex:1;min-width:220px;}
.pub-count{color:var(--muted);font-size:14px;}
.pub-index{position:sticky;top:64px;z-index:20;display:flex;flex-wrap:wrap;gap:8px;padding:14px 0;margin-bottom:8px;background:var(--bg);border-bottom:1px solid var(--line);}
.pub-index a{font-size:13px;font-weight:600;color:var(--blue);background:var(--sky);padding:5px 12px;border-radius:999px;text-decoration:none;transition:background .15s,color .15s;}
.pub-index a:hover{background:var(--blue);color:#fff;}
.pub-year{scroll-margin-top:120px;margin:26px 0 12px;color:var(--blue);font-weight:800;font-size:20px;border-bottom:2px solid var(--sky);padding-bottom:6px;}
.pub{padding:14px 0;border-bottom:1px solid var(--line);font-size:14.8px;line-height:1.7;}
.pub b{color:var(--blue-d);}
.pub .pub-title{font-weight:600;color:var(--ink);}
.pub .links{margin-top:4px;}
.pub .links a{font-size:13px;margin-right:12px;}

/* ---- News (article layout) ---- */
.news-article{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:30px 34px;margin-bottom:30px;}
.news-article .na-head .tag{display:inline-block;background:var(--sky);color:var(--blue);font-size:12px;font-weight:700;padding:3px 12px;border-radius:999px;}
.news-article .na-head .date{color:var(--muted);font-size:13px;margin-left:10px;}
.news-article h2{margin:12px 0 18px;font-size:23px;color:var(--blue-d);font-weight:800;line-height:1.35;}
.news-article .na-img{width:100%;max-height:460px;object-fit:cover;border-radius:12px;margin-bottom:20px;background:var(--sky);}
.news-article .na-body p{color:var(--ink);font-size:15.5px;line-height:1.95;margin-bottom:14px;text-align:justify;}
.news-article .na-src{color:var(--muted);font-size:13.5px;margin-top:18px;}
.news-article .na-link{margin-top:6px;font-weight:600;}
@media(max-width:640px){.news-article{padding:22px 20px;}}

/* ---- Join ---- */
.join-pos{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:24px;margin-bottom:18px;}
.join-pos h4{color:var(--blue-d);font-size:19px;margin-bottom:8px;}
.join-pos ul{margin:10px 0 0 20px;color:var(--muted);font-size:14.5px;}
.callout{background:var(--sky);border:1px solid #cfe2f6;border-radius:14px;padding:24px;margin-top:24px;}
.callout b{color:var(--blue-d);}
/* bilingual: Chinese text shown as a secondary line under English */
.zh{display:block;color:var(--muted);font-size:13.5px;line-height:1.7;margin-top:3px;opacity:.92;}
.join-pos li .zh{margin-bottom:8px;}
.zh-inline{color:var(--accent);font-weight:500;font-size:.82em;margin-left:6px;}

/* ---- Footer ---- */
.footer{background:var(--blue-d);color:#c5d6ea;padding:40px 24px 28px;margin-top:40px;}
.footer .wrap{display:flex;flex-wrap:wrap;gap:30px;justify-content:space-between;}
.footer h5{color:#fff;font-size:15px;margin-bottom:10px;}
.footer a{color:#c5d6ea;}
.footer .bottom{text-align:center;color:#8fb0d4;font-size:13px;margin-top:24px;border-top:1px solid rgba(255,255,255,.12);padding-top:18px;}

/* ---- responsive ---- */
@media(max-width:860px){
  .g4,.g3{grid-template-columns:repeat(2,1fr);}
  .nav .menu{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;flex-direction:column;border-bottom:1px solid var(--line);padding:8px 16px;}
  .nav .menu.open{display:flex;}
  .nav .burger{display:block;}
  .hero h1{font-size:32px;}
  /* on narrow screens allow the long second line to wrap to avoid overflow */
  .hero h1 span{white-space:normal !important;}
}
@media(max-width:560px){.g4,.g3,.g2{grid-template-columns:1fr;}}