/* Wentang Song — academic homepage */
:root{
  --bg:#ffffff;
  --bg-alt:#f6f7f9;
  --text:#17191d;
  --muted:#69707a;
  --line:#e5e7eb;
  --accent:#2457d6;
  --accent-soft:#edf2ff;
  --max:1080px;
  --serif:"Source Serif 4", Georgia, serif;
  --sans:"Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--sans);line-height:1.7}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.container{width:min(calc(100% - 48px),var(--max));margin:0 auto}
.site-header{position:sticky;top:0;z-index:10;background:rgba(255,255,255,.92);backdrop-filter:blur(12px);border-bottom:1px solid rgba(229,231,235,.85)}
.nav-wrap{width:min(calc(100% - 48px),var(--max));margin:auto;height:66px;display:flex;align-items:center;justify-content:space-between}
.brand{font-weight:700;letter-spacing:.08em;color:var(--text);font-size:15px}
nav{display:flex;gap:28px}
nav a{font-size:13px;font-weight:500;color:var(--muted)}
nav a:hover{color:var(--text);text-decoration:none}
.hero{min-height:680px;display:grid;grid-template-columns:1.6fr .8fr;gap:80px;align-items:center;padding:100px 0 110px}
.eyebrow{text-transform:uppercase;letter-spacing:.14em;font-size:11px;font-weight:700;color:var(--accent);margin:0 0 18px}
h1{font-family:var(--serif);font-size:clamp(56px,8vw,92px);line-height:.98;letter-spacing:-.055em;margin:0 0 28px;font-weight:700}
.tagline{font-size:22px;line-height:1.45;max-width:690px;margin:0 0 22px;color:#30343b}
.tagline span{color:var(--accent)}
.intro{max-width:690px;color:var(--muted);font-size:15px}
.links{display:flex;flex-wrap:wrap;gap:10px;margin-top:28px}
.pill{display:inline-flex;align-items:center;border:1px solid var(--line);border-radius:999px;padding:8px 14px;color:var(--text);font-size:12px;font-weight:600}
.pill:hover{background:var(--bg-alt);text-decoration:none}
.pill.primary{background:var(--text);border-color:var(--text);color:white}
.hero-card{border:1px solid var(--line);padding:28px;background:linear-gradient(145deg,#fff,#fafafa);box-shadow:0 18px 50px rgba(20,30,50,.06)}
.avatar-placeholder{width:100%;aspect-ratio:1/1;border-radius:50%;display:grid;place-items:center;background:#eef0f3;color:#a0a6ae;font-family:var(--serif);font-size:64px;font-weight:700;margin-bottom:30px}
.card-label{font-size:10px;text-transform:uppercase;letter-spacing:.14em;color:var(--muted);margin:10px 0 2px}
.card-title{font-size:16px;font-weight:700;margin:0}
.card-meta{font-size:12px;color:var(--muted);margin:0}
.mini-line{height:1px;background:var(--line);margin:22px 0}
.section{padding:105px 0}
.section-alt{background:var(--bg-alt)}
.section-heading{display:flex;align-items:baseline;gap:15px;margin-bottom:48px}
.section-heading span{font-size:11px;letter-spacing:.12em;color:var(--accent);font-weight:700}
.section-heading h2{font-family:var(--serif);font-size:38px;line-height:1.1;margin:0;letter-spacing:-.035em}
.two-col{display:grid;grid-template-columns:1.1fr .9fr;gap:90px}
.two-col p{font-size:15px;color:var(--muted)}
.two-col strong{color:var(--text)}
.focus-list{border-top:1px solid var(--line)}
.focus-list>div{display:grid;grid-template-columns:38px 1fr;gap:8px;padding:18px 0;border-bottom:1px solid var(--line)}
.focus-list span{font-size:11px;color:var(--accent);padding-top:2px}
.focus-list strong{font-size:14px}
.focus-list small{grid-column:2;color:var(--muted);font-size:12px}
.research-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.research-card{background:white;border:1px solid var(--line);padding:28px;min-height:300px;display:flex;flex-direction:column}
.number{font-size:11px;color:var(--accent);font-weight:700;letter-spacing:.12em}
.research-card h3{font-family:var(--serif);font-size:26px;line-height:1.15;margin:55px 0 12px}
.research-card p{font-size:13px;color:var(--muted);margin:0}
.tags{display:flex;gap:7px;flex-wrap:wrap;margin-top:auto;padding-top:25px}
.tags span{font-size:10px;border:1px solid var(--line);padding:4px 7px;color:var(--muted)}
.section-note{color:var(--muted);font-size:13px;margin:-20px 0 40px}
.pub-list{border-top:1px solid var(--line)}
.publication{display:grid;grid-template-columns:90px 1fr;gap:20px;padding:30px 0;border-bottom:1px solid var(--line)}
.pub-year{font-size:12px;color:var(--accent);font-weight:700;padding-top:4px}
.publication h3{font-family:var(--serif);font-size:22px;line-height:1.3;margin:0 0 8px;letter-spacing:-.015em}
.authors,.venue{font-size:12px;margin:3px 0;color:var(--muted)}
.venue{font-style:italic}
.pub-links{display:flex;gap:14px;margin-top:12px}
.pub-links a{font-size:11px;font-weight:700}
.timeline{border-top:1px solid var(--line)}
.timeline-item{display:grid;grid-template-columns:180px 1fr;gap:30px;padding:25px 0;border-bottom:1px solid var(--line)}
.timeline-date{font-size:12px;color:var(--accent);font-weight:600}
.timeline-item h3{font-size:16px;margin:0 0 3px}
.timeline-item p{font-size:13px;color:var(--muted);margin:0}
.contact{text-align:center;padding:120px 0}
.contact h2{font-family:var(--serif);font-size:44px;line-height:1.1;letter-spacing:-.035em;margin:0 auto 18px;max-width:650px}
.email-link{font-size:14px;font-weight:600}
footer{border-top:1px solid var(--line);padding:24px 0;color:var(--muted);font-size:10px}
.footer-inner{display:flex;justify-content:space-between;gap:20px}
@media(max-width:800px){
  .hero{grid-template-columns:1fr;gap:50px;padding:75px 0}
  .hero-card{max-width:360px}
  .two-col,.research-grid{grid-template-columns:1fr;gap:35px}
  .research-card{min-height:260px}
  nav{gap:14px}
  nav a:nth-child(3),nav a:nth-child(4){display:none}
}
@media(max-width:520px){
  .container,.nav-wrap{width:min(calc(100% - 30px),var(--max))}
  h1{font-size:56px}
  .tagline{font-size:19px}
  .section{padding:75px 0}
  .publication{grid-template-columns:1fr;gap:4px}
  .timeline-item{grid-template-columns:1fr;gap:5px}
  .contact h2{font-size:35px}
  .footer-inner{flex-direction:column}
}