/* ===== XSYDA Research — editorial/academic design system ===== */
:root{
  --bg:#ffffff;
  --paper:#fbfbf8;
  --ink:#16181d;
  --ink-soft:#3c3f47;
  --muted:#6c707a;
  --line:#e6e5de;
  --line-strong:#d4d3ca;
  --accent:#1f3a8a;
  --accent-soft:#eef2fb;
  --serif:'Spectral', Georgia, 'Times New Roman', serif;
  --sans:'IBM Plex Sans', system-ui, sans-serif;
  --mono:'IBM Plex Mono', ui-monospace, monospace;
  --wrap:1140px;
  --gut:clamp(20px,5vw,48px);
}
*{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:var(--sans);font-size:17px;line-height:1.65;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
a{color:var(--accent);text-decoration:none;}
a:hover{text-decoration:underline;text-underline-offset:3px;}
h1,h2,h3,h4{font-family:var(--serif);font-weight:500;line-height:1.18;color:var(--ink);letter-spacing:-0.01em;margin:0;}
p{margin:0 0 1.1em;}
img{max-width:100%;display:block;}
.wrap{max-width:var(--wrap);margin:0 auto;padding-left:var(--gut);padding-right:var(--gut);}
.eyebrow{font-family:var(--mono);font-size:12px;letter-spacing:0.18em;text-transform:uppercase;color:var(--muted);margin:0 0 14px;}
.rule{height:1px;background:var(--line);border:0;margin:0;}
.muted{color:var(--muted);}
.lead{font-size:clamp(18px,2.4vw,21px);line-height:1.62;color:var(--ink-soft);}

/* fade-in (single, subtle) */
.fade{animation:fade .5s ease both;}
@keyframes fade{from{opacity:0;transform:translateY(8px);}to{opacity:1;transform:none;}}
@media (prefers-reduced-motion: reduce){.fade{animation:none;}}

/* ===== Navbar ===== */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.9);backdrop-filter:saturate(1.2) blur(6px);border-bottom:1px solid var(--line);}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:68px;}
.brand{display:flex;align-items:center;gap:11px;color:var(--ink);font-family:var(--serif);font-size:20px;font-weight:600;letter-spacing:-0.01em;}
.brand:hover{text-decoration:none;}
.brand img{width:26px;height:26px;}
.brand .sub{font-family:var(--mono);font-size:11px;letter-spacing:0.22em;text-transform:uppercase;color:var(--muted);font-weight:400;}
.nav-links{display:flex;gap:30px;align-items:center;}
.nav-links a{font-size:14.5px;color:var(--ink-soft);font-weight:500;}
.nav-links a:hover{color:var(--accent);text-decoration:none;}
.nav-links a.active{color:var(--accent);}
.nav-toggle{display:none;background:none;border:1px solid var(--line-strong);border-radius:6px;padding:7px 10px;font-family:var(--mono);font-size:12px;cursor:pointer;color:var(--ink);}
@media(max-width:820px){
  .nav-links{position:absolute;top:68px;left:0;right:0;flex-direction:column;gap:0;background:var(--bg);border-bottom:1px solid var(--line);padding:8px var(--gut) 16px;}
  .nav-links a{padding:11px 0;border-bottom:1px solid var(--line);}
  .nav-links.closed{display:none;}
  .nav-toggle{display:inline-block;}
}

/* ===== Sections ===== */
.section{padding:clamp(56px,8vw,104px) 0;}
.section.paper{background:var(--paper);border-top:1px solid var(--line);border-bottom:1px solid var(--line);}
.section-head{max-width:760px;margin-bottom:44px;}

/* ===== Hero ===== */
.hero{padding:clamp(72px,12vw,150px) 0 clamp(48px,7vw,86px);}
.hero h1{font-size:clamp(40px,7vw,76px);font-weight:500;letter-spacing:-0.025em;line-height:1.04;max-width:14ch;}
.hero .lead{max-width:60ch;margin-top:26px;}
.btns{display:flex;flex-wrap:wrap;gap:14px;margin-top:38px;}
.btn{display:inline-flex;align-items:center;gap:8px;font-family:var(--mono);font-size:13px;letter-spacing:0.04em;padding:13px 22px;border-radius:7px;border:1px solid var(--accent);background:var(--accent);color:#fff;cursor:pointer;transition:opacity .15s;}
.btn:hover{opacity:.88;text-decoration:none;}
.btn.ghost{background:transparent;color:var(--accent);}
.btn.ghost:hover{background:var(--accent-soft);}

/* ===== Featured paper ===== */
.feature{display:grid;grid-template-columns:1fr;gap:0;border:1px solid var(--line-strong);border-radius:12px;overflow:hidden;background:var(--bg);}
.feature-body{padding:clamp(26px,4vw,42px);}
.feature h3{font-size:clamp(22px,3vw,30px);line-height:1.2;margin:10px 0 14px;max-width:34ch;}
.meta-row{display:flex;flex-wrap:wrap;gap:8px 18px;font-family:var(--mono);font-size:12.5px;color:var(--muted);margin-top:18px;}
.meta-row span{white-space:nowrap;}

/* ===== Cards grid ===== */
.grid{display:grid;gap:20px;grid-template-columns:repeat(3,1fr);}
@media(max-width:900px){.grid{grid-template-columns:repeat(2,1fr);}}
@media(max-width:600px){.grid{grid-template-columns:1fr;}}
.card{border:1px solid var(--line);border-radius:11px;padding:26px;background:var(--bg);transition:border-color .15s, transform .15s;}
.card:hover{border-color:var(--line-strong);}
.card .num{font-family:var(--mono);font-size:12px;color:var(--accent);letter-spacing:0.1em;}
.card h3{font-size:20px;margin:12px 0 9px;}
.card p{font-size:15px;color:var(--ink-soft);margin:0;line-height:1.6;}
a.card:hover{text-decoration:none;}

/* ===== Page header ===== */
.page-head{padding:clamp(56px,9vw,110px) 0 clamp(30px,5vw,52px);border-bottom:1px solid var(--line);}
.page-head h1{font-size:clamp(34px,5.5vw,58px);font-weight:500;letter-spacing:-0.02em;max-width:18ch;}
.page-head .lead{margin-top:20px;max-width:62ch;}

/* ===== Prose / content blocks ===== */
.prose{max-width:72ch;}
.prose h2{font-size:clamp(24px,3.4vw,32px);margin:1.6em 0 .5em;}
.prose h3{font-size:20px;font-family:var(--sans);font-weight:600;margin:1.5em 0 .4em;}
.prose p{color:var(--ink-soft);}
.prose ul{color:var(--ink-soft);padding-left:1.2em;margin:0 0 1.1em;}
.prose li{margin-bottom:.4em;}

/* research area block */
.area{padding:clamp(40px,6vw,70px) 0;border-bottom:1px solid var(--line);}
.area:last-child{border-bottom:0;}
.area-grid{display:grid;grid-template-columns:1fr 1.4fr;gap:clamp(24px,5vw,64px);}
@media(max-width:820px){.area-grid{grid-template-columns:1fr;gap:24px;}}
.area h2{font-size:clamp(26px,3.6vw,36px);}
.subblock{margin-bottom:26px;}
.subblock h4{font-family:var(--mono);font-size:12px;letter-spacing:0.14em;text-transform:uppercase;color:var(--accent);font-weight:500;margin-bottom:8px;}
.subblock p,.subblock ul{font-size:15.5px;color:var(--ink-soft);margin:0;}
.subblock ul{padding-left:1.15em;}

/* ===== Publication card ===== */
.pub{border:1px solid var(--line-strong);border-radius:12px;padding:clamp(26px,4vw,40px);background:var(--bg);}
.pub h2{font-size:clamp(22px,3vw,30px);line-height:1.22;margin:14px 0 16px;max-width:36ch;}
.tag{display:inline-block;font-family:var(--mono);font-size:11px;letter-spacing:0.14em;text-transform:uppercase;color:var(--accent);background:var(--accent-soft);border-radius:4px;padding:4px 9px;}
.pub-meta{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:18px;margin:22px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:18px 0;}
.pub-meta dt{font-family:var(--mono);font-size:11px;letter-spacing:0.1em;text-transform:uppercase;color:var(--muted);margin-bottom:4px;}
.pub-meta dd{margin:0;font-size:15px;color:var(--ink);}

/* ===== Artifacts ===== */
.artifact{display:flex;justify-content:space-between;align-items:baseline;gap:20px;padding:20px 0;border-bottom:1px solid var(--line);}
.artifact h3{font-size:18px;font-family:var(--sans);font-weight:600;}
.artifact p{font-size:14.5px;color:var(--muted);margin:5px 0 0;max-width:60ch;}
.status{font-family:var(--mono);font-size:11px;letter-spacing:0.08em;text-transform:uppercase;color:var(--muted);border:1px solid var(--line-strong);border-radius:20px;padding:4px 12px;white-space:nowrap;}

/* ===== Contact ===== */
.contact-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:28px;}
.contact-item h4{font-family:var(--mono);font-size:12px;letter-spacing:0.12em;text-transform:uppercase;color:var(--muted);font-weight:500;margin-bottom:8px;}
.contact-item p,.contact-item a{font-size:16px;}

/* ===== Footer ===== */
.foot{border-top:1px solid var(--line);background:var(--paper);padding:48px 0 40px;margin-top:0;}
.foot-grid{display:flex;justify-content:space-between;flex-wrap:wrap;gap:28px;}
.foot .brand{font-size:18px;}
.foot-links{display:flex;flex-wrap:wrap;gap:22px;}
.foot-links a{font-size:14px;color:var(--ink-soft);}
.foot-bottom{margin-top:34px;padding-top:20px;border-top:1px solid var(--line);font-family:var(--mono);font-size:12px;color:var(--muted);display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;}

/* ===== Accessibility & responsiveness hardening ===== */
html,body{overflow-x:hidden;max-width:100%;}
.skip{position:absolute;left:-9999px;top:0;background:var(--ink);color:#fff;padding:10px 16px;border-radius:0 0 6px 0;z-index:100;font-family:var(--mono);font-size:13px;}
.skip:focus{left:0;text-decoration:none;}
a:focus-visible,button:focus-visible,.btn:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:4px;}
.btn{min-height:44px;}
.nav-toggle{min-height:40px;min-width:44px;}
.nav-links a{min-height:24px;}
img{height:auto;}
@media(max-width:380px){
  :root{--gut:18px;}
  .hero h1{font-size:34px;}
}
/* governance section */
.gov-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:24px;margin-top:18px;}
.gov-item h4{font-family:var(--mono);font-size:12px;letter-spacing:0.1em;text-transform:uppercase;color:var(--accent);font-weight:500;margin-bottom:7px;}
.gov-item p{font-size:14.5px;color:var(--ink-soft);margin:0;}
.note{background:var(--accent-soft);border-left:3px solid var(--accent);padding:14px 18px;border-radius:0 7px 7px 0;font-size:14.5px;color:var(--ink-soft);margin:8px 0 28px;}
.status.available{color:#1d6b3a;border-color:#9ed3b0;}
.status.released{color:var(--accent);border-color:#9bb6e8;}
.status.archived{color:#6c707a;}