/* ═══════════════════════════════════════════════════
   Lab website styles (CWI-inspired)
   Site colors are defined here via CSS variables; no need to touch the code below
   ═══════════════════════════════════════════════════ */
:root{
  --bg:#FFFFFF;            /* Page background */
  --ink:#111111;           /* Primary text (near-black) */
  --ink-2:#55595E;         /* Secondary text (graphite gray) */
  --line:#E3E5E8;          /* Dividers */
  --accent:#E4572E;        /* Accent (CWI-style orange-red; links/hover/tags) */
  --dark:#16181D;          /* Dark blocks (footer/join section/buttons) */
  --paper:#F6F6F4;         /* Light gray (alternate sections) */
  --font:"PingFang SC","Helvetica Neue","Microsoft YaHei",sans-serif;
  --w:1160px;              /* Max content width */
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.7;font-size:15.5px}
img{max-width:100%;display:block}
a{color:var(--ink);text-decoration:none}
.container{max-width:var(--w);margin:0 auto;padding:0 28px}

/* ── Common elements ── */
.eyebrow{font-size:12px;letter-spacing:2.5px;text-transform:uppercase;color:var(--accent);font-weight:600;margin-bottom:10px}
.sec-title{font-size:34px;font-weight:700;letter-spacing:-.5px;line-height:1.2;margin-bottom:14px}
.sec-row{display:flex;align-items:flex-end;justify-content:space-between;gap:20px;margin-bottom:34px}
.textlink{color:var(--accent);font-weight:600;font-size:14px;white-space:nowrap}
.textlink:hover{text-decoration:underline}
.btn{display:inline-block;padding:12px 30px;font-size:14px;font-weight:600;border:1px solid transparent}
.btn-dark{background:var(--dark);color:#fff}
.btn-dark:hover{background:var(--accent)}

/* ── Top bar ── */
.topbar{background:var(--dark);color:#9CA1AA;font-size:12px}
.topbar .container{display:flex;justify-content:space-between;height:34px;align-items:center}
.topbar-links a{color:#C9CDD4;margin-left:18px}
.topbar-links a:hover{color:#fff}

/* ── Navigation ── */
.nav{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.94);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.nav .container{display:flex;align-items:center;height:64px;gap:32px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:17px;letter-spacing:-.3px}
.brand .mark{width:26px;height:26px;border-radius:6px;background:var(--accent);position:relative}
.brand .mark::after{content:"";position:absolute;inset:7px;border-radius:50%;background:#fff}
.menu{display:flex;gap:2px;margin-left:auto}
.menu a{padding:8px 14px;font-size:14px;color:var(--ink-2);border-radius:4px;font-weight:500}
.menu a:hover{color:var(--ink);background:var(--paper)}
.menu a.active{color:var(--accent)}
.nav-toggle{display:none;margin-left:auto;background:none;border:none;font-size:20px;cursor:pointer}

/* ── Hero ── */
.hero{position:relative;min-height:560px;display:flex;align-items:flex-end;color:#fff;overflow:hidden}
.hero-media{position:absolute;inset:0;background:
  linear-gradient(160deg,#1B1F26 0%,#232830 55%,#2A303A 100%)}
.hero-media img{position:absolute;right:0;top:0;height:100%;width:52%;object-fit:cover;object-position:center 42%;
  -webkit-mask-image:linear-gradient(to left,#000 22%,rgba(0,0,0,.5) 50%,transparent 88%),linear-gradient(to bottom,transparent 0%,#000 14%,#000 80%,rgba(0,0,0,.45) 100%);
  -webkit-mask-composite:source-in;
          mask-image:linear-gradient(to left,#000 22%,rgba(0,0,0,.5) 50%,transparent 88%),linear-gradient(to bottom,transparent 0%,#000 14%,#000 80%,rgba(0,0,0,.45) 100%);
          mask-composite:intersect}
.hero-media::after{content:"";position:absolute;inset:0;background:linear-gradient(0deg,rgba(8,9,12,.85) 0%,rgba(8,9,12,.25) 55%,rgba(8,9,12,.35) 100%)}
.hero-text{position:relative;z-index:2;padding-top:120px;padding-bottom:64px;width:100%}
.hero h1{font-size:52px;font-weight:800;letter-spacing:-1px;line-height:1.1;max-width:760px}
.hero .eyebrow{color:var(--accent)}
.hero .lead{max-width:620px;color:#D8DBE0;font-size:17px;margin:18px 0 28px}

/* ── Project cards ── */
.projects{padding:96px 0}
.project-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:24px}
.gcard{border:1px solid var(--line);border-radius:8px;overflow:hidden;transition:transform .2s,box-shadow .2s}
.gcard:hover{transform:translateY(-4px);box-shadow:0 10px 26px rgba(0,0,0,.10)}
.gcard .thumb{height:150px;background:repeating-linear-gradient(135deg,#E9EAE7 0 12px,#DFE1DD 12px 24px);display:flex;align-items:center;justify-content:center;color:#9AA0A6;font-size:12px}
.gcard .thumb img{width:100%;height:100%;object-fit:cover}
.gcard .body{padding:20px 22px 24px}
.gcard h3{font-size:17px;margin-bottom:8px}
.gcard p{font-size:13.5px;color:var(--ink-2);margin-bottom:14px;
  display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}

/* ── Project detail modal ── */
.modal{position:fixed;inset:0;background:rgba(20,22,26,.55);backdrop-filter:blur(3px);
  display:flex;align-items:center;justify-content:center;padding:24px;z-index:200;
  opacity:0;visibility:hidden;transition:opacity .2s,visibility .2s}
.modal.open{opacity:1;visibility:visible}
.modal-panel{background:#fff;border-radius:10px;max-width:760px;width:100%;max-height:86vh;overflow:auto;
  position:relative;transform:translateY(14px);transition:transform .2s}
.modal.open .modal-panel{transform:translateY(0)}
.modal-close{position:absolute;top:10px;right:12px;width:34px;height:34px;border:none;border-radius:50%;
  background:rgba(255,255,255,.92);font-size:22px;line-height:1;cursor:pointer;color:var(--ink);
  box-shadow:0 2px 10px rgba(0,0,0,.15)}
.modal-close:hover{background:#fff}
.modal-thumb{height:300px;background:repeating-linear-gradient(135deg,#E9EAE7 0 12px,#DFE1DD 12px 24px);
  display:flex;align-items:center;justify-content:center;color:#9AA0A6;font-size:13px}
.modal-thumb img{width:100%;height:100%;object-fit:cover;border-radius:10px 10px 0 0}
.modal-body{padding:26px 30px 32px}
.modal-body h3{font-size:21px;margin-bottom:6px}
.modal-desc{color:var(--accent);font-size:14px;font-weight:600;margin-bottom:16px}
.modal-text{color:var(--ink-2);font-size:14.5px;line-height:1.75}
.modal-text p{margin-bottom:12px}
.modal-text p:last-child{margin-bottom:0}
.modal-text a{color:var(--accent);font-weight:600}
.modal-text a:hover{text-decoration:underline}
.modal-refs{margin-top:20px;padding-top:16px;border-top:1px solid #E5E6E2}
.modal-refs h4{font-size:13px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-2);margin-bottom:10px}
.modal-refs ol{padding-left:20px;counter-reset:none}
.modal-refs li{font-size:13px;color:var(--ink-2);line-height:1.65;margin-bottom:8px;padding-left:4px}
.modal-refs li::marker{color:var(--accent);font-weight:700}
.modal-refs a{color:var(--accent);font-weight:600}
.modal-refs a:hover{text-decoration:underline}
/* ── Alumni modal (reuses .modal; wider panel so the 3-column list has room) ── */
.alum-panel{max-width:920px}
.alum-panel .modal-desc{margin-bottom:20px}
/* Summary-only variant (no entry list, just the headline number) */
.alum-note-panel{max-width:560px}
.alum-note-panel .modal-body{padding-bottom:26px}
.alum-note-panel .modal-desc{margin-bottom:0}
/* In-card pointer to an external page (e.g. the IIP alumni list). The arrow
   drifts up-right on hover to signal that the link opens in a new tab. */
.modal-more{display:inline-flex;align-items:center;gap:6px;margin-top:15px;font-size:13.5px;
  font-weight:600;color:var(--accent)}
.modal-more:hover,.modal-more:focus-visible{text-decoration:underline}
.modal-more span{font-size:12px;line-height:1;transition:transform .18s}
.modal-more:hover span,.modal-more:focus-visible span{transform:translate(2px,-2px)}

/* ── News ── */
.news{background:var(--paper);padding:88px 0}
.news-item{display:grid;grid-template-columns:110px 84px 1fr;gap:20px;align-items:baseline;padding:18px 0;border-bottom:1px solid #D5D7D2}
.news-item .date{font-size:13.5px;color:var(--ink-2);font-variant-numeric:tabular-nums}
.news-item .tag{font-size:11.5px;font-weight:700;color:var(--accent);letter-spacing:1px;text-transform:uppercase}
.news-item .tag-paper{color:var(--accent)}
.news-item .tag-project{color:#0F766E}
.news-item .tag-honor{color:#B8860B}
.news-item .tag-visit{color:#4477AA}
.news-item .tag-opening{color:#188038}
.news-item .tag-standard{color:#6D4FC2}
.news-item .txt{font-size:15px}
.news-item .txt a:hover{color:var(--accent)}

/* ── Publications ── */
.pubs{padding:96px 0}
.pub{display:grid;grid-template-columns:110px 1fr;gap:24px;padding:24px 0;border-bottom:1px solid var(--line)}
.pub .venue{font-size:11.5px;font-weight:800;letter-spacing:.5px;color:#fff;background:var(--dark);padding:4px 10px;border-radius:3px;align-self:start;text-align:center}
.pub .venue.journal{background:var(--accent)}
.pub .venue.arxiv{background:#6E7780}
.pub h3{font-size:17.5px;line-height:1.4;margin-bottom:6px}
.pub h3 a:hover{color:var(--accent)}
.pub .authors{font-size:13.5px;color:var(--ink-2)}
.pub .authors b{color:var(--ink)}
.pub .plinks{margin-top:8px;font-size:13px}
.pub .plinks a{color:var(--accent);margin-right:14px;font-weight:600}
.pub .plinks a:hover{text-decoration:underline}
.pub .plinks .na{color:#A6ABB0;margin-right:14px;font-weight:600;cursor:default}

/* ── Team ── */
.team{background:var(--paper);padding:96px 0}
.director{display:flex;gap:32px;align-items:center;background:#fff;border-radius:8px;padding:30px 34px;margin-bottom:36px;border:1px solid #E5E6E2}
.director .avatar{flex:0 0 96px;height:96px;border-radius:50%;background:var(--dark);color:#fff;font-size:30px;font-weight:700;display:flex;align-items:center;justify-content:center;object-fit:cover}
.director h3{font-size:20px;margin-bottom:2px}
.director .role{color:var(--accent);font-size:13.5px;font-weight:600;margin-bottom:10px}
.director p{color:var(--ink-2);font-size:14px}
.people-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:20px}
.person{background:#fff;border:1px solid #E5E6E2;border-radius:8px;padding:22px 12px;text-align:center}
.person .avatar{width:72px;height:72px;border-radius:50%;object-fit:cover;margin:0 auto 10px;display:block}
.person .nm{font-size:14.5px;font-weight:600}
.person .role{font-size:12px;color:var(--ink-2)}
/* Initials avatar (used when a member has no photo yet) — same circle as .person .avatar,
   declared after it so display:flex wins over the base display:block. */
.person .avatar-initials{display:flex;align-items:center;justify-content:center;
  background:#E9EAE7;color:#8A9099;font-size:19px;font-weight:700;letter-spacing:.5px;user-select:none}
.sub-title{font-size:13px;font-weight:700;letter-spacing:1.5px;text-transform:uppercase;color:var(--ink-2);margin:0 0 18px}
.people-grid + .sub-title{margin-top:40px}
.people-grid + .alum-row{margin-top:40px}
/* ── Alumni headings in one row, three equal columns ──
   The second selector outranks the generic ".sub-title + .sub-title" spacing rule
   further down, which would otherwise push cards 2 and 3 out of line. */
.alum-row{display:grid;grid-template-columns:repeat(3,1fr);gap:0 28px}
.alum-row .sub-title,.alum-row .sub-title + .sub-title{margin:0}
/* ── Clickable section heading (opens a modal card instead of listing content inline) ── */
.sub-title.is-clickable{cursor:pointer;display:flex;align-items:center;gap:9px;transition:color .18s}
.sub-title.is-clickable:hover,.sub-title.is-clickable:focus-visible{color:var(--accent);outline:none}
.sub-title.is-clickable .cnt{font-weight:600;letter-spacing:0;color:#A6ABB0;transition:color .18s}
.sub-title.is-clickable .chev{font-size:14px;line-height:1;transition:transform .18s}
.sub-title.is-clickable:hover .cnt,.sub-title.is-clickable:focus-visible .cnt{color:var(--accent)}
.sub-title.is-clickable:hover .chev,.sub-title.is-clickable:focus-visible .chev{transform:translateX(3px)}
/* consecutive clickable headings (e.g. Ph.D. Alumni / M.Sc.·M.Eng. Alumni) */
.sub-title + .sub-title{margin-top:26px}
.alum-list{display:grid;grid-template-columns:repeat(3,1fr);gap:0 48px}
.alum{padding:6px 0;border-bottom:1px solid #E5E6E2}
.alum .row1{display:flex;justify-content:space-between;align-items:baseline;gap:16px}
.alum .nm{font-weight:600;font-size:13.5px}
.alum .yr{font-size:12px;color:var(--ink-2);font-variant-numeric:tabular-nums}
.alum .note{margin-top:1px;font-size:12px;color:var(--ink-2);line-height:1.45}

/* ── Join us + Contact (dark block) ── */
.join{background:var(--dark);color:#C9CDD4;padding:96px 0}
.join-grid{display:grid;grid-template-columns:7fr 5fr;gap:64px;align-items:start}
.join-list{list-style:none;margin-top:10px}
.join-list li{padding:14px 0 14px 26px;border-bottom:1px solid #2A2E36;position:relative;font-size:15px}
.join-list a{color:var(--accent);font-weight:600;text-decoration:none;border-bottom:1px solid transparent}
.join-list a:hover{border-bottom-color:var(--accent)}
.join-list li::before{content:"—";position:absolute;left:0;color:var(--accent);font-weight:700}
.join-card{background:#1D2026;border:1px solid #2A2E36;border-radius:10px;padding:32px 34px}
.join-card h3{color:#fff;font-size:18px;margin-bottom:18px}
.join-card p{font-size:14px;margin-bottom:12px}
.join-card b{color:#fff}

/* ── Footer ── */
footer{background:#0C0D10;color:#8B8F97;padding:56px 0;font-size:13.5px}
.footer-grid{display:flex;justify-content:space-between;gap:30px;flex-wrap:wrap}
.fbrand{color:#fff;font-size:16px;font-weight:700;margin-bottom:8px}
.copy{text-align:right}

/* ── Back to top ── */
#toTop{position:fixed;right:26px;bottom:30px;width:44px;height:44px;border-radius:50%;background:var(--accent);color:#fff;border:none;cursor:pointer;font-size:18px;display:none;box-shadow:0 6px 16px rgba(228,87,46,.4)}
#toTop.show{display:block}

/* ── Responsive ── */
@media(max-width:900px){
  .hero h1{font-size:34px}
  .hero-media img{width:78%}
  .join-grid{grid-template-columns:1fr;gap:36px}
  .sec-row{flex-direction:column;align-items:flex-start;gap:6px}
  .news-item{grid-template-columns:96px 1fr;row-gap:4px}
  .news-item .tag{grid-column:1}
  .pub{grid-template-columns:1fr}
  .director{flex-direction:column;text-align:center}
  .alum-list{grid-template-columns:1fr;gap:0}
  .alum-row{grid-template-columns:1fr;gap:0}
  .alum-row .sub-title + .sub-title{margin-top:22px}
  .menu{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);flex-direction:column;padding:10px 20px}
  .menu.open{display:flex}
  .nav-toggle{display:block}
}