/* ============ Qavis site system ============ */
:root{
  --ink:#0B1826;
  --ink-2:#101F33;
  --ink-3:#16283F;
  --paper:#F7F8F6;
  --white:#FFFFFF;
  --text:#13202F;
  --muted:#54677C;
  --line:rgba(13,28,44,.13);
  --teal:#0B7A70;
  --teal-bright:#2BD9C8;
  --teal-soft:#E4F3F0;
  --green:#1F9D66;
  --blue:#2E6FD8;
  --font-display:"Inter Tight",-apple-system,sans-serif;
  --font-body:"Inter",-apple-system,sans-serif;
  --font-mono:"IBM Plex Mono",ui-monospace,monospace;
  --radius:10px;
  --maxw:1180px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--font-body);
  font-size:16px;line-height:1.6;
  color:var(--text);
  background:var(--paper);
  -webkit-font-smoothing:antialiased;
}
a{color:var(--teal);text-decoration:none}
a:hover{color:var(--ink)}
img{max-width:100%;display:block}
::selection{background:var(--teal-bright);color:var(--ink)}

h1,h2,h3,h4{font-family:var(--font-display);font-weight:700;line-height:1.08;letter-spacing:-0.02em;color:var(--ink);text-wrap:balance}
.display{font-size:clamp(40px,5.4vw,72px);font-weight:800}
h2.sec-title{font-size:clamp(30px,3.6vw,46px);margin-bottom:14px}
h3{font-size:21px;line-height:1.25}
p{text-wrap:pretty}
.lede{font-size:clamp(17px,1.5vw,20px);color:var(--muted);max-width:60ch}

.container{max-width:var(--maxw);margin:0 auto;padding:0 28px}
.section{padding:96px 0}
.section.tight{padding:64px 0}
.sec-head{max-width:760px;margin-bottom:52px}
.eyebrow{
  font-family:var(--font-mono);font-size:12.5px;font-weight:500;
  text-transform:uppercase;letter-spacing:.14em;color:var(--teal);
  display:block;margin-bottom:16px;
}

/* ---------- nav ---------- */
.nav{
  position:sticky;top:0;z-index:50;
  background:transparent;
  border-bottom:1px solid transparent;
  transition:background .28s ease,border-color .28s ease,backdrop-filter .28s ease;
}
.nav.scrolled{
  background:rgba(247,248,246,.92);
  backdrop-filter:blur(16px);
  -webkit-backdrop-filter:blur(16px);
  border-bottom-color:var(--line);
}
.nav-inner{
  max-width:var(--maxw);margin:0 auto;padding:0 28px;
  display:flex;align-items:center;gap:36px;
  height:80px;transition:height .28s ease;
}
.nav.scrolled .nav-inner{height:64px}
.logo{display:flex;align-items:center}
.logo:hover{opacity:.85}
.logo-img{height:40px;width:auto;display:block;transition:height .28s ease;margin-left:-8px}
.nav.scrolled .logo-img{height:30px}
.nav-links{display:flex;align-items:center;gap:28px;margin-left:auto}
.nav-links>a{font-size:14.5px;font-weight:500;color:var(--text)}
.nav-links>a:hover,.nav-links>a.on{color:var(--teal)}
.nav-links>a.on{position:relative}
.nav-links>a.on::after{content:"";position:absolute;left:0;right:0;bottom:-24px;height:2px;background:var(--teal)}
.dropdown{position:relative}
.dropdown>a{font-size:14.5px;font-weight:500;color:var(--text);display:inline-flex;align-items:center;gap:5px}
.dropdown>a::after{content:"";width:7px;height:7px;border-right:1.6px solid currentColor;border-bottom:1.6px solid currentColor;transform:rotate(45deg) translateY(-2px)}
.dropdown>a.on{color:var(--teal)}
.dropdown-menu{
  position:absolute;top:calc(100% + 14px);left:-16px;min-width:250px;
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:0 16px 40px rgba(11,24,38,.12);padding:8px;
  opacity:0;visibility:hidden;transform:translateY(-6px);transition:.18s;
}
.dropdown:hover .dropdown-menu,.dropdown:focus-within .dropdown-menu{opacity:1;visibility:visible;transform:none}
.dropdown-menu a{display:block;padding:11px 14px;border-radius:7px;color:var(--text);font-size:14.5px}
.dropdown-menu a:hover{background:var(--teal-soft);color:var(--ink)}
.dropdown-menu a small{display:block;color:var(--muted);font-size:12.5px;font-weight:400}
.nav-cta{margin-left:6px}
.nav-burger{display:none;margin-left:auto;background:none;border:0;cursor:pointer;padding:8px}
.nav-burger span{display:block;width:22px;height:2px;background:var(--ink);margin:5px 0}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:9px;
  font-family:var(--font-body);font-size:15px;font-weight:600;
  padding:13px 24px;border-radius:8px;border:1px solid transparent;
  cursor:pointer;transition:.16s;white-space:nowrap;
}
.btn-primary{background:var(--ink);color:var(--paper)}
.btn-primary:hover{background:var(--teal);color:#fff}
.btn-ghost{border-color:var(--line);color:var(--ink);background:transparent}
.btn-ghost:hover{border-color:var(--teal);color:var(--teal)}
.btn .arr{transition:transform .16s}
.btn:hover .arr{transform:translateX(3px)}

/* ---------- cards & grids ---------- */
.grid{display:grid;gap:20px}
.grid.c2{grid-template-columns:repeat(2,1fr)}
.grid.c3{grid-template-columns:repeat(3,1fr)}
.grid.c4{grid-template-columns:repeat(4,1fr)}
.card{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius);
  padding:28px;transition:transform .18s,box-shadow .18s;
}
a.card{color:var(--text)}
a.card:hover{transform:translateY(-4px);box-shadow:0 18px 40px rgba(11,24,38,.10);color:var(--text)}
.card h3{margin-bottom:8px}
.card p{font-size:14.5px;color:var(--muted)}
.card .mono-tag{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--teal);display:block;margin-bottom:14px}

.chip{
  display:inline-block;font-family:var(--font-mono);font-size:11.5px;
  padding:4px 10px;border:1px solid var(--line);border-radius:99px;
  color:var(--muted);background:var(--paper);
}
.chip-row{display:flex;flex-wrap:wrap;gap:7px;margin-top:16px}

/* ---------- metrics ---------- */
.metric-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.metric{border-top:2px solid var(--teal);padding-top:18px}
.metric .num{font-family:var(--font-display);font-size:clamp(34px,3.6vw,52px);font-weight:800;letter-spacing:-.03em;color:var(--ink);line-height:1}
.metric .lbl{font-family:var(--font-mono);font-size:12.5px;color:var(--muted);margin-top:10px;letter-spacing:.06em;text-transform:uppercase}
.metric .note{font-size:13px;color:var(--muted);margin-top:6px}

/* ---------- alternating blocks ---------- */
.alt-block{display:grid;grid-template-columns:1fr 1fr;gap:64px;align-items:center;padding:56px 0}
.alt-block + .alt-block{border-top:1px solid var(--line)}
.alt-block.flip .alt-media{order:2}
.alt-media{
  background:var(--white);border:1px solid var(--line);border-radius:var(--radius);
  min-height:300px;display:flex;align-items:center;justify-content:center;overflow:hidden;
}

/* ---------- steps / scroll narrative ---------- */
.steps{position:relative;display:grid;gap:0}
.step{
  display:grid;grid-template-columns:72px 1fr;gap:28px;padding:36px 0;
  border-top:1px solid var(--line);
}
.step-num{
  font-family:var(--font-mono);font-size:14px;color:var(--teal);
  padding-top:4px;
}
.step h3{margin-bottom:8px}
.step p{color:var(--muted);max-width:62ch}

/* ---------- tabs ---------- */
.tabbar{display:flex;flex-wrap:wrap;gap:8px;border-bottom:1px solid var(--line);padding-bottom:16px;margin-bottom:36px}
.tabbar button{
  font-family:var(--font-body);font-size:14.5px;font-weight:600;
  padding:10px 18px;border-radius:8px;border:1px solid var(--line);
  background:var(--white);color:var(--muted);cursor:pointer;transition:.15s;
}
.tabbar button:hover{color:var(--ink);border-color:var(--teal)}
.tabbar button.on{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.tabpanel{display:none}
.tabpanel.on{display:block}

/* ---------- publications ---------- */
.pub-card{background:var(--white);border:1px solid var(--line);border-radius:var(--radius);padding:26px;display:flex;flex-direction:column;gap:12px}
.pub-card .badge{
  align-self:flex-start;font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;text-transform:uppercase;
  padding:4px 10px;border-radius:4px;background:var(--teal-soft);color:var(--teal);
}
.pub-card .badge.paper{background:var(--ink);color:var(--teal-bright)}
.pub-card h3{font-size:18px}
.pub-card .date{font-family:var(--font-mono);font-size:12px;color:var(--muted)}
.pub-card .pub-act{margin-top:auto;padding-top:8px;font-weight:600;font-size:14px}

/* ---------- trust / logo strip ---------- */
.strip{
  display:flex;flex-wrap:wrap;gap:14px 40px;align-items:center;
  font-family:var(--font-mono);font-size:13px;letter-spacing:.05em;color:var(--muted);
}
.strip b{color:var(--ink);font-weight:600}

/* ---------- dark band (shared CTA) ---------- */
.band{
  background:var(--ink);color:#B9C6D6;border-radius:16px;
  padding:clamp(40px,6vw,80px);
}
.band h2{color:var(--paper);font-size:clamp(28px,3.4vw,44px);margin-bottom:12px}
.band p{max-width:56ch}
.band .btn-primary{background:var(--teal-bright);color:var(--ink)}
.band .btn-primary:hover{background:#fff;color:var(--ink)}
.band a:not(.btn){color:var(--teal-bright)}
.band a:not(.btn):hover{color:#fff}

/* ---------- footer ---------- */
.footer{border-top:1px solid var(--line);padding:64px 0 40px;background:var(--white)}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;margin-bottom:48px}
.footer h4{font-size:13px;font-family:var(--font-mono);font-weight:500;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);margin-bottom:16px}
.footer a{display:block;color:var(--text);font-size:14.5px;padding:4px 0}
.footer a:hover{color:var(--teal)}
.footer .mission{color:var(--muted);font-size:14.5px;max-width:32ch;margin-top:12px}
.footer-logo{height:32px;width:auto;display:block;margin-left:-8px}
.footer-base{display:flex;justify-content:space-between;gap:20px;border-top:1px solid var(--line);padding-top:24px;font-size:13px;color:var(--muted);flex-wrap:wrap}

/* ---------- forms ---------- */
.field{margin-bottom:18px}
.field label{display:block;font-size:13.5px;font-weight:600;color:var(--ink);margin-bottom:7px}
.field input,.field select,.field textarea{
  width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:8px;
  font-family:var(--font-body);font-size:15px;color:var(--text);background:var(--white);
}
.field input:focus,.field select:focus,.field textarea:focus{outline:2px solid var(--teal-bright);outline-offset:0;border-color:var(--teal)}

/* ---------- page transition overlay ---------- */
body::before{
  content:'';position:fixed;inset:0;
  background:var(--paper);
  z-index:9998;pointer-events:none;
  animation:pgReveal .32s ease forwards;
}
@keyframes pgReveal{from{opacity:1}to{opacity:0}}
body.page-leaving::before{animation:pgLeave .22s ease forwards}
@keyframes pgLeave{from{opacity:0}to{opacity:1}}
@media(prefers-reduced-motion:reduce){body::before{display:none}}

/* ---------- reveal ---------- */
.rv{opacity:0;transform:translateY(22px);transition:opacity .7s cubic-bezier(.16,1,.3,1),transform .7s cubic-bezier(.16,1,.3,1)}
.rv.in{opacity:1;transform:none}
/* grid card stagger */
.grid>.rv:nth-child(2){transition-delay:.09s}
.grid>.rv:nth-child(3){transition-delay:.18s}
.grid>.rv:nth-child(4){transition-delay:.27s}
.grid>.rv:nth-child(5){transition-delay:.36s}
.grid>.rv:nth-child(6){transition-delay:.45s}
@media (prefers-reduced-motion:reduce){.rv{opacity:1;transform:none;transition:none}}

/* ---------- inner page hero entrance ---------- */
@keyframes pageIn{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:none}}
.page-hero .ctx  {animation:pageIn .55s cubic-bezier(.16,1,.3,1) .05s both}
.page-hero h1    {animation:pageIn .65s cubic-bezier(.16,1,.3,1) .15s both}
.page-hero .lede {animation:pageIn .6s  cubic-bezier(.16,1,.3,1) .3s  both}
@media (prefers-reduced-motion:reduce){
  .page-hero .ctx,.page-hero h1,.page-hero .lede{animation:none}
}

/* ---------- context bar (inner pages) ---------- */
.ctx{
  font-size:13.5px;color:var(--muted);border:1px solid var(--line);
  background:var(--white);border-radius:99px;padding:8px 18px;display:inline-block;margin-bottom:28px;
}
.ctx b{color:var(--ink);font-weight:600}

/* ---------- page hero ---------- */
.page-hero{padding:88px 0 64px}
.page-hero .lede{margin-top:18px}

/* ---------- responsive ---------- */
@media (max-width:960px){
  .grid.c3,.grid.c4{grid-template-columns:repeat(2,1fr)}
  .alt-block{grid-template-columns:1fr;gap:28px}
  .alt-block.flip .alt-media{order:0}
  .footer-grid{grid-template-columns:1fr 1fr}
  .metric-strip{grid-template-columns:1fr}
  .nav-links{
    display:none;position:absolute;top:68px;left:0;right:0;
    background:var(--white);border-bottom:1px solid var(--line);
    flex-direction:column;align-items:flex-start;padding:20px 28px;gap:16px;
  }
  .nav-links.open{display:flex}
  .nav-links>a.on::after{display:none}
  .nav-burger{display:block}
  .dropdown-menu{position:static;opacity:1;visibility:visible;transform:none;box-shadow:none;border:0;padding:4px 0 0 12px;min-width:0}
}
@media (max-width:640px){
  .grid.c2,.grid.c3,.grid.c4{grid-template-columns:1fr}
  .section{padding:64px 0}
  .step{grid-template-columns:44px 1fr;gap:16px}
}

/* ---------- article layout (blog + papers) ---------- */
.art-back{font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--teal-bright);margin-bottom:28px;display:inline-block}
.art-meta{display:flex;gap:14px;align-items:center;margin-bottom:32px;flex-wrap:wrap;font-size:13px;font-family:var(--font-mono);color:var(--muted)}
.art-grid{display:grid;grid-template-columns:1fr 268px;gap:64px;align-items:start}
.art-body h2{font-size:22px;margin:44px 0 12px;color:#F2F5F3}
.art-body h3{font-size:17px;margin:28px 0 8px;color:#DDE5EC}
.art-body p{font-size:16px;line-height:1.78;color:#B9C6D6;margin-bottom:16px}
.art-body p+p{margin-top:0}
.art-body p b{color:#DDE5EC}
.art-body ul,.art-body ol{padding-left:20px;margin:10px 0 18px}
.art-body li{font-size:15.5px;line-height:1.65;color:#B9C6D6;margin-bottom:6px}
.art-body li b{color:#DDE5EC}
.art-body blockquote{border-left:3px solid var(--teal-bright);padding:14px 22px;margin:28px 0;background:rgba(43,217,200,.07);border-radius:0 8px 8px 0}
.art-body blockquote p{color:#DDE5EC;font-weight:600;font-size:16.5px;margin:0}
.art-body a{color:var(--teal-bright)}
.art-body a:hover{color:#fff}
/* KaTeX math in article context */
.art-body .katex{font-size:1.04em;color:#E4EBF2}
.art-body .katex-display{margin:26px 0;overflow-x:auto;overflow-y:hidden;padding:6px 2px}
.art-body .katex-display>.katex{text-align:center}
.art-stat-box{background:rgba(14,27,48,.8);border:1px solid rgba(43,217,200,.22);border-radius:12px;padding:20px 26px;margin:28px 0;display:flex;align-items:center;gap:22px}
.art-stat-box .n{font-size:34px;font-weight:800;color:var(--teal-bright);font-family:var(--font-display);white-space:nowrap;line-height:1}
.art-stat-box .lbl{font-size:14px;color:#8FA1B5;line-height:1.5}
.art-aside{position:sticky;top:90px}
.aside-card{background:rgba(14,27,48,.7);border:1px solid rgba(185,198,214,.14);border-radius:12px;padding:22px;margin-bottom:18px}
.aside-card h4{font-size:11px;font-family:var(--font-mono);letter-spacing:.1em;text-transform:uppercase;color:#66788D;margin-bottom:12px}
.aside-card ul{list-style:none;padding:0;margin:0}
.aside-card li{font-size:13.5px;color:#B9C6D6;padding:6px 0 6px 14px;position:relative;border-bottom:1px solid rgba(185,198,214,.1)}
.aside-card li:last-child{border-bottom:none}
.aside-card li::before{content:"";position:absolute;left:0;top:14px;width:5px;height:5px;background:var(--teal-bright);border-radius:50%}
.aside-card a{color:#B9C6D6;font-size:13.5px}
.aside-card a:hover{color:var(--teal-bright)}
/* paper-specific */
.paper-abstract{background:rgba(14,27,48,.7);border:1px solid rgba(185,198,214,.14);border-radius:12px;padding:28px 32px;margin:32px 0}
.paper-abstract h3{font-size:13px;font-family:var(--font-mono);letter-spacing:.1em;text-transform:uppercase;color:#66788D;margin-bottom:14px}
.paper-abstract p{font-size:15.5px;line-height:1.75;color:#B9C6D6;margin:0}
.paper-h2{font-size:22px;margin:36px 0 14px;color:#F2F5F3;font-family:var(--font-display)}
.paper-results{list-style:none;padding:0;margin:14px 0}
.paper-results li{position:relative;padding:10px 0 10px 20px;border-bottom:1px solid rgba(185,198,214,.1);font-size:15.5px;line-height:1.6;color:#B9C6D6}
.paper-results li:last-child{border-bottom:none}
.paper-results li::before{content:"";position:absolute;left:0;top:18px;width:5px;height:5px;background:var(--teal-bright);border-radius:50%}
.paper-results li b{color:#DDE5EC}
.paper-cite{background:rgba(6,12,25,.6);border:1px solid rgba(185,198,214,.1);border-radius:10px;padding:20px 24px;font-family:var(--font-mono);font-size:12.5px;color:#66788D;line-height:1.7;margin-top:32px}
.paper-cite b{color:#8FA1B5;display:block;margin-bottom:8px;font-size:11px;letter-spacing:.08em;text-transform:uppercase}
@media(max-width:900px){.art-grid{grid-template-columns:1fr}.art-aside{position:static}}

/* ---------- resources / blog / papers listing ---------- */
.pub-card{position:relative}
.pub-card p{font-size:14px;color:var(--muted)}
.pin-tag{position:absolute;top:18px;right:18px;font-family:var(--font-mono);font-size:10px;letter-spacing:.08em;text-transform:uppercase;color:var(--teal);background:var(--teal-soft);padding:3px 9px;border-radius:99px}
.papers{background:var(--ink);border-radius:16px;padding:clamp(32px,5vw,64px)}
.papers h2{color:#F2F5F3}
.papers .lede{color:#8FA1B5}
.papers .pub-card{background:#0E1B30;border-color:rgba(185,198,214,.14)}
.papers .pub-card h3{color:#F2F5F3}
.papers .pub-card p{color:#8FA1B5}
.papers .pub-card .date{color:#66788D}
.papers a{color:var(--teal-bright)}
.papers a:hover{color:#fff}
.papers .pin-tag{background:rgba(43,217,200,.14);color:var(--teal-bright)}
.view-all{margin-top:30px;display:flex;justify-content:flex-end}
.view-all a{font-family:var(--font-mono);font-size:13px;letter-spacing:.04em;color:var(--teal);display:inline-flex;align-items:center;gap:6px}
.view-all a:hover{color:var(--ink)}
.papers .view-all a{color:var(--teal-bright)}
.papers .view-all a:hover{color:#fff}
/* empty state — shown until the first entry is published */
.empty-state{border:1px dashed var(--line);border-radius:16px;padding:clamp(40px,6vw,64px) 40px;text-align:center;max-width:660px;margin:0 auto}
.empty-state .es-icon{font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--teal);display:block;margin-bottom:18px}
.empty-state h3{font-size:clamp(20px,2.4vw,26px);margin-bottom:12px}
.empty-state p{color:var(--muted);font-size:15px;max-width:46ch;margin:0 auto 26px}
.papers .empty-state{border-color:rgba(185,198,214,.2)}
.papers .empty-state h3{color:#F2F5F3}
.papers .empty-state p{color:#8FA1B5}