/* Rui Zhong — academic website | light green with light blue accents */
:root{
  --ink:#1f3d37;
  --ink-soft:#587a71;
  --green:#3f9c7d;
  --green-deep:#2d7a61;
  --green-pale:#e9f5f0;
  --blue:#4f9cbf;
  --blue-pale:#eaf4f9;
  --bg:#f8fbfa;
  --card:#ffffff;
  --line:#e2eee8;
  --radius:14px;
  --shadow:0 6px 22px -12px rgba(31,61,55,.18);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:'Inter',system-ui,sans-serif;
  color:var(--ink);
  background:var(--bg);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3{font-family:'Fraunces',Georgia,serif;font-weight:600;letter-spacing:-.01em}
a{color:var(--green-deep);text-decoration:none}
a:hover{color:var(--blue)}
.wrap{max-width:1080px;margin:0 auto;padding:0 24px}
main{min-height:60vh}
section{padding:72px 0}
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-size:.76rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;
  color:var(--green);margin-bottom:12px;
}
.eyebrow::before{content:"";width:24px;height:2px;background:var(--green);border-radius:2px}
h1.page-title{font-size:clamp(2rem,4.5vw,2.8rem);margin-bottom:10px}
h2{font-size:clamp(1.5rem,3vw,2rem);margin-bottom:10px}
.section-sub{color:var(--ink-soft);max-width:660px;margin-bottom:36px;font-size:.97rem}
.src{font-size:.78rem;color:var(--ink-soft)}
.src a{color:var(--blue);border-bottom:1px dotted #bcd9e6}
.src a:hover{color:var(--green-deep)}

/* ---------- Nav ---------- */
nav{
  position:sticky;top:0;z-index:100;
  background:rgba(248,251,250,.92);
  backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:62px}
.logo{font-family:'Fraunces',Georgia,serif;font-weight:700;font-size:1.12rem;color:var(--ink)}
.logo span{color:var(--green)}
.nav-links{display:flex;gap:22px;list-style:none;align-items:center}
.nav-links a{font-size:.86rem;font-weight:500;color:var(--ink-soft)}
.nav-links a:hover{color:var(--green-deep)}
.nav-links a.active{color:var(--green-deep);font-weight:600;border-bottom:2px solid var(--green);padding-bottom:3px}
.nav-cta{
  font-size:.8rem;font-weight:600;color:#fff!important;
  background:var(--green);padding:8px 16px;border-radius:999px;border-bottom:none!important;
}
.nav-cta:hover{background:var(--green-deep)}
.burger{display:none;background:none;border:none;font-size:1.5rem;color:var(--ink);cursor:pointer}

/* ---------- Page header band ---------- */
.page-head{
  background:linear-gradient(180deg,#edf7f2 0%,var(--bg) 100%);
  border-bottom:1px solid var(--line);
  padding:64px 0 48px;
}
.page-head p.lead{color:var(--ink-soft);max-width:680px}

/* ---------- Hero (home) ---------- */
.hero{
  background:linear-gradient(180deg,#ecf7f1 0%,#f2f9f6 60%,var(--bg) 100%);
  border-bottom:1px solid var(--line);
  padding:84px 0 64px;
}
.hero-grid{display:grid;grid-template-columns:1.3fr .7fr;gap:56px;align-items:center}
.hero h1{font-size:clamp(2.5rem,5.5vw,3.6rem);font-weight:700;line-height:1.08;margin-bottom:14px}
.hero h1 span{color:var(--green)}
.hero .role{font-size:1.04rem;font-weight:600;margin-bottom:4px}
.hero .org{font-size:.94rem;color:var(--ink-soft);margin-bottom:4px}
.hero .maf{margin-bottom:20px}
.hero .org a{border-bottom:1px dotted #b9d6cb}
.hero .interests{color:var(--ink-soft);max-width:580px;margin-bottom:24px;font-size:.99rem}
.hero .interests strong{color:var(--ink);font-weight:600}
.cred-chips{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:26px}
.chip{
  font-size:.73rem;font-weight:600;letter-spacing:.03em;
  background:#fff;border:1px solid var(--line);color:var(--green-deep);
  padding:6px 12px;border-radius:999px;
}
.chip.blue{color:var(--blue);border-color:#d7e9f2}
a.chip:hover{border-color:var(--green);color:var(--green-deep)}
.cta-row{display:flex;flex-wrap:wrap;gap:11px}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  font-size:.88rem;font-weight:600;padding:11px 20px;border-radius:999px;
  transition:all .15s ease;border:1.5px solid transparent;
}
.btn:hover{transform:translateY(-1px)}
.btn-primary{background:var(--green);color:#fff!important}
.btn-primary:hover{background:var(--green-deep)}
.btn-outline{border-color:var(--green);color:var(--green-deep)!important;background:#fff}
.btn-outline:hover{background:var(--green-pale)}
.btn-blue{border-color:#cde4ef;color:var(--blue)!important;background:var(--blue-pale)}
.btn-blue:hover{background:#ddeef7}
.btn svg{width:15px;height:15px;fill:currentColor}
.portrait-col{display:flex;justify-content:center}
.portrait-frame{
  width:min(280px,75vw);aspect-ratio:5/6;border-radius:18px;overflow:hidden;
  border:1px solid var(--line);background:#fff;padding:8px;box-shadow:var(--shadow);
}
.portrait-frame img{width:100%;height:100%;object-fit:cover;border-radius:12px;display:block}
.portrait-fallback{
  display:none;width:100%;height:100%;border-radius:12px;
  align-items:center;justify-content:center;
  font-family:'Fraunces',Georgia,serif;font-size:4rem;font-weight:700;
  color:var(--green-deep);background:linear-gradient(150deg,var(--green-pale),var(--blue-pale));
}

/* ---------- Stats ---------- */
.stats{background:#fff;border-bottom:1px solid var(--line);padding:30px 0}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;text-align:center}
.stat .num{font-family:'Fraunces',Georgia,serif;font-size:1.9rem;font-weight:700;color:var(--green-deep)}
.stat .lbl{font-size:.8rem;color:var(--ink-soft)}
.stat .lbl a{color:inherit;border-bottom:1px dotted #b9d6cb}

/* ---------- Achievement cards (home) ---------- */
.ach-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.ach-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px 28px;
}
.ach-card:hover{box-shadow:var(--shadow)}
.ach-card .ico{
  width:40px;height:40px;border-radius:10px;display:flex;align-items:center;justify-content:center;
  font-size:1.15rem;margin-bottom:14px;background:var(--green-pale);
}
.ach-card:nth-child(even) .ico{background:var(--blue-pale)}
.ach-card h3{font-size:1.08rem;margin-bottom:10px}
.ach-card ul{list-style:none;display:grid;gap:9px}
.ach-card li{font-size:.87rem;color:var(--ink-soft);padding-left:16px;position:relative}
.ach-card li::before{content:"";position:absolute;left:0;top:10px;width:6px;height:6px;border-radius:50%;background:var(--green)}
.ach-card li a{border-bottom:1px dotted #b9d6cb}
.ach-card .more{display:inline-block;margin-top:14px;font-size:.82rem;font-weight:600}
.ach-card .more::after{content:" →"}

/* ---------- Generic cards ---------- */
.card-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px;
}
.card:hover{box-shadow:var(--shadow)}
.card .ico{
  width:40px;height:40px;border-radius:10px;display:flex;align-items:center;justify-content:center;
  background:var(--green-pale);margin-bottom:14px;font-size:1.15rem;
}
.card h3{font-size:1.06rem;margin-bottom:8px}
.card p{font-size:.88rem;color:var(--ink-soft)}
.kw{margin-top:13px;display:flex;flex-wrap:wrap;gap:6px}
.kw span{font-size:.69rem;font-weight:600;padding:4px 10px;border-radius:999px;background:var(--green-pale);color:var(--green-deep)}
.kw span.blue{background:var(--blue-pale);color:var(--blue)}

/* ---------- Flagship / spotlight ---------- */
.flagship{
  background:var(--card);border:1px solid var(--line);border-left:4px solid var(--green);
  border-radius:8px var(--radius) var(--radius) 8px;
  padding:30px 32px;margin-bottom:24px;
}
.flag-label{font-size:.71rem;font-weight:700;letter-spacing:.13em;text-transform:uppercase;color:var(--blue);margin-bottom:8px}
.flagship h3{font-size:1.3rem;line-height:1.3;margin-bottom:6px}
.flagship h3 a{color:var(--ink)}
.flagship h3 a:hover{color:var(--green-deep)}
.flagship .meta{font-size:.88rem;color:var(--ink-soft);margin-bottom:16px}
.impact-row{display:flex;flex-wrap:wrap;gap:9px}
.impact{
  display:inline-flex;align-items:center;gap:7px;font-size:.78rem;font-weight:600;
  background:var(--green-pale);color:var(--green-deep);
  border:1px solid #d4eae0;padding:7px 13px;border-radius:999px;
}
.impact:hover{border-color:var(--green)}
.impact.blue{background:var(--blue-pale);color:var(--blue);border-color:#d7e9f2}
.impact.blue:hover{border-color:var(--blue)}
.spot-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.spot-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px}
.spot-card:hover{box-shadow:var(--shadow)}
.spot-card .tag{font-size:.69rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--blue)}
.spot-card h4{font-family:'Fraunces',Georgia,serif;font-size:1.02rem;margin:7px 0;line-height:1.35}
.spot-card p{font-size:.84rem;color:var(--ink-soft)}
.spot-card p a{border-bottom:1px dotted #b9d6cb}

/* ---------- SDG ---------- */
.sdg-strip{margin-top:40px;text-align:center}
.sdg-strip .lbl{font-size:.8rem;color:var(--ink-soft);margin-bottom:12px}
.sdgs{display:flex;flex-wrap:wrap;gap:8px;justify-content:center}
.sdg{font-size:.74rem;font-weight:600;color:#fff;padding:7px 13px;border-radius:8px;opacity:.92}

/* ---------- Publications ---------- */
.filter-row{display:flex;flex-wrap:wrap;gap:9px;margin-bottom:28px}
.fbtn{
  font-family:'Inter',sans-serif;font-size:.8rem;font-weight:600;cursor:pointer;
  padding:8px 16px;border-radius:999px;border:1.5px solid var(--line);background:#fff;color:var(--ink-soft);
  transition:all .15s ease;
}
.fbtn:hover{border-color:var(--green)}
.fbtn.active{background:var(--green);color:#fff;border-color:var(--green)}
.pub-list{display:grid;gap:11px}
.pub{
  display:grid;grid-template-columns:58px 1fr auto;gap:16px;align-items:baseline;
  background:var(--card);border:1px solid var(--line);border-radius:12px;padding:17px 20px;
}
.pub:hover{border-color:#c5e0d4;box-shadow:var(--shadow)}
.pub .yr{font-family:'Fraunces',Georgia,serif;font-weight:700;font-size:1rem;color:var(--blue)}
.pub .ti{font-weight:600;font-size:.92rem;line-height:1.45}
.pub .ti a{color:var(--ink)}
.pub .ti a:hover{color:var(--green-deep)}
.pub .jr{font-size:.82rem;color:var(--ink-soft);font-style:italic}
.pub .note{font-size:.77rem;color:var(--green-deep);font-weight:600;margin-top:3px}
.pub .note a{border-bottom:1px dotted #b9d6cb}
.badges{display:flex;gap:6px;flex-wrap:wrap;justify-content:flex-end}
.bdg{font-size:.66rem;font-weight:700;letter-spacing:.04em;padding:4px 8px;border-radius:6px}
.bdg.ft{background:var(--green-deep);color:#dff3ea}
.bdg.astar{background:var(--green-pale);color:var(--green-deep);border:1px solid #d4eae0}
.bdg.a{background:var(--blue-pale);color:var(--blue);border:1px solid #d7e9f2}
.pub.hidden{display:none}
.wp-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.wp{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:20px}
.wp:hover{box-shadow:var(--shadow)}
.wp .st{font-size:.68rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--blue)}
.wp h4{font-size:.92rem;font-weight:600;margin:6px 0 4px;line-height:1.4;font-family:'Inter',sans-serif}
.wp h4 a{color:var(--ink)}
.wp h4 a:hover{color:var(--green-deep)}
.wp p{font-size:.8rem;color:var(--ink-soft)}

/* ---------- About / timeline ---------- */
.about-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:44px;align-items:start}
.about-text p{color:var(--ink-soft);margin-bottom:15px;font-size:.95rem}
.about-text strong{color:var(--ink)}
.about-text a{border-bottom:1px dotted #b9d6cb}
.side-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px}
.side-card h3{font-size:1.03rem;margin-bottom:16px}
.timeline{border-left:2px solid var(--line);padding-left:20px;display:grid;gap:16px}
.t-item{position:relative}
.t-item::before{
  content:"";position:absolute;left:-26px;top:7px;width:9px;height:9px;border-radius:50%;
  background:var(--green);box-shadow:0 0 0 3px var(--green-pale);
}
.t-item .t-when{font-size:.72rem;font-weight:600;letter-spacing:.07em;color:var(--blue);text-transform:uppercase}
.t-item .t-what{font-weight:600;font-size:.92rem}
.t-item .t-where{font-size:.84rem;color:var(--ink-soft)}

/* ---------- Grants ---------- */
.grant-list{display:grid}
.grant{
  display:grid;grid-template-columns:1fr auto;gap:18px;align-items:baseline;
  padding:19px 4px;border-bottom:1px solid var(--line);
}
.grant:last-child{border-bottom:none}
.grant .amt{font-family:'Fraunces',Georgia,serif;font-weight:700;font-size:1.08rem;color:var(--green-deep)}
.grant .gt{font-weight:600;font-size:.92rem}
.grant .gt a{color:var(--ink);border-bottom:1px dotted #b9d6cb}
.grant .gt a:hover{color:var(--green-deep)}
.grant .gf{font-size:.81rem;color:var(--ink-soft)}
.grant .gy{font-size:.78rem;font-weight:600;color:var(--blue);white-space:nowrap}

/* ---------- Awards ---------- */
.award-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.award{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:21px;display:flex;gap:14px;align-items:flex-start}
.award:hover{box-shadow:var(--shadow)}
.award .yr{font-family:'Fraunces',Georgia,serif;font-weight:700;color:var(--blue);font-size:.98rem;min-width:44px}
.award p{font-size:.88rem;font-weight:600;line-height:1.45}
.award p a{color:var(--ink);border-bottom:1px dotted #b9d6cb}
.award p a:hover{color:var(--green-deep)}
.award span{display:block;font-size:.77rem;font-weight:500;color:var(--ink-soft);margin-top:3px}

/* ---------- Teaching ---------- */
.teach-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.teach-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px}
.teach-card h3{font-size:1rem;margin-bottom:13px}
.teach-card ul{list-style:none;display:grid;gap:8px}
.teach-card li{font-size:.85rem;color:var(--ink-soft);padding-left:16px;position:relative}
.teach-card li::before{content:"";position:absolute;left:0;top:9px;width:6px;height:6px;border-radius:50%;background:var(--green)}

/* ---------- Contact ---------- */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.contact-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:28px}
.contact-card h3{font-size:1.05rem;margin-bottom:12px}
.contact-card p,.contact-card li{font-size:.9rem;color:var(--ink-soft)}
.contact-card ul{list-style:none;display:grid;gap:9px}
.contact-card a{border-bottom:1px dotted #b9d6cb}

/* ---------- Footer ---------- */
footer{background:#eef6f1;border-top:1px solid var(--line);padding:44px 0 26px;margin-top:24px}
.foot-grid{display:grid;grid-template-columns:1.2fr .8fr .9fr;gap:36px;margin-bottom:30px}
footer h3{font-size:1rem;margin-bottom:10px}
footer p,footer li{font-size:.84rem;color:var(--ink-soft)}
footer ul{list-style:none;display:grid;gap:7px}
.foot-bottom{border-top:1px solid var(--line);padding-top:18px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px;font-size:.76rem;color:var(--ink-soft)}

/* ---------- Responsive ---------- */
@media(max-width:900px){
  .hero-grid{grid-template-columns:1fr;gap:36px}
  .portrait-col{order:-1}
  .about-grid{grid-template-columns:1fr}
  .ach-grid,.card-grid,.wp-grid,.award-grid,.contact-grid{grid-template-columns:1fr}
  .spot-grid{grid-template-columns:1fr}
  .teach-grid{grid-template-columns:1fr 1fr}
  .stats-grid{grid-template-columns:1fr 1fr;gap:24px}
  .foot-grid{grid-template-columns:1fr}
  .nav-links{
    display:none;position:absolute;top:62px;left:0;right:0;
    background:#fff;border-bottom:1px solid var(--line);
    flex-direction:column;padding:18px 24px;gap:14px;align-items:flex-start;
  }
  .nav-links.open{display:flex}
  .burger{display:block}
}
@media(max-width:560px){
  .pub{grid-template-columns:1fr}
  .badges{justify-content:flex-start}
  .grant{grid-template-columns:1fr}
  .teach-grid{grid-template-columns:1fr}
  section{padding:54px 0}
}