:root{
    --navy:#1e1b4b;
    --indigo:#4338ca;
    --indigo-2:#6366f1;
    --ink:#111827;
    --body:#374151;
    --dim:#6b7280;
    --line:#e5e7eb;
    --bg:#ffffff;
    --bg-soft:#f9fafb;
    --bg-tint:#f5f3ff;
  }
  *{box-sizing:border-box;margin:0;padding:0}
  html{scroll-behavior:smooth}
  body{background:var(--bg);color:var(--body);font-family:'Inter',system-ui,sans-serif;font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased}
  .wrap{max-width:1080px;margin:0 auto;padding:0 28px}
  a{color:var(--indigo)}

  .topbar{background:var(--navy);position:sticky;top:0;z-index:50}
  .topbar .wrap{display:flex;align-items:center;justify-content:space-between;height:56px}
  .brand{font-family:'Inter';font-weight:700;font-size:15px;letter-spacing:.02em;color:#fff}
  .brand span{color:var(--indigo-2)}
  .brand-logo{display:block;height:26px;width:auto;filter:brightness(0) invert(1)}
  .nav{display:flex;gap:22px;font-size:13.5px;font-weight:500}
  .nav a{color:#c7d2fe;text-decoration:none;transition:color .15s}
  .nav a:hover{color:#fff}
  @media(max-width:820px){.nav{display:none}}

  .banner{background:var(--navy);color:#fff;position:relative;overflow:hidden}
  .hero-img{display:block;width:100%;max-width:1400px;margin:0 auto;height:auto}
  @media(max-width:640px){
    .hero-img{height:200px;object-fit:cover;object-position:left 40%}
  }
  .hero-overlay{position:relative;padding:34px 28px 52px}
  .mobile-title{display:none}
  @media(max-width:640px){
    .mobile-title{display:block;font-family:'Source Serif 4',serif;font-weight:700;color:#fff;font-size:34px;line-height:1.1;margin-bottom:16px}
    .mobile-title span{color:#c7d2fe;font-weight:600;font-size:26px}
    .hero-overlay{padding:26px 22px 44px}
  }
  .full-name{font-size:clamp(15px,1.8vw,18px);color:#c7d2fe;font-weight:400;max-width:64ch;line-height:1.5}
  .full-name b{color:#fff;font-weight:600}
  .banner-meta{margin-top:32px;display:flex;flex-wrap:wrap;gap:12px}
  .chip{font-family:'IBM Plex Mono',monospace;font-size:clamp(13px,1.25vw,16px);background:rgba(255,255,255,.08);border:1px solid rgba(199,210,254,.3);color:#e0e7ff;padding:clamp(8px,1vw,12px) clamp(13px,1.4vw,20px);border-radius:4px;line-height:1.2}
  .chip b{color:#fff}
  .chip-link{text-decoration:none;display:inline-flex;align-items:center;gap:8px;transition:background .15s,border-color .15s}
  .chip-link:hover{background:rgba(255,255,255,.14);border-color:rgba(199,210,254,.55)}
  .chip-map{font-size:.85em;opacity:.8}

  /* countdown */
  .countdown{margin-top:28px;display:flex;flex-wrap:wrap;align-items:center;gap:22px;padding-top:26px;border-top:1px solid rgba(199,210,254,.2)}
  .cd-label{font-family:'IBM Plex Mono',monospace;font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;color:#a5b4fc}
  .cd-units{display:flex;gap:14px}
  .cd-unit{text-align:center;min-width:58px}
  .cd-num{font-family:'Source Serif 4',serif;font-weight:700;font-size:34px;color:#fff;line-height:1;font-variant-numeric:tabular-nums}
  .cd-tag{font-family:'IBM Plex Mono',monospace;font-size:10.5px;letter-spacing:.08em;text-transform:uppercase;color:#a5b4fc;margin-top:6px}
  .cd-closed{font-family:'Source Serif 4',serif;font-size:22px;color:#fff}
  .hero-btn{display:inline-block;margin-top:0;margin-left:auto;background:var(--indigo-2);color:#fff;text-decoration:none;
    font-family:'Inter';font-weight:600;font-size:clamp(15px,1.4vw,17px);padding:14px 30px;border-radius:6px;
    transition:background .15s,transform .15s;box-shadow:0 2px 14px rgba(99,102,241,.35);white-space:nowrap}
  .hero-btn:hover{background:#818cf8;transform:translateY(-1px)}
  @media(max-width:640px){.hero-btn{margin-left:0;margin-top:6px}}

  section.block{padding:58px 0;border-bottom:1px solid var(--line)}
  .sec-head{display:flex;align-items:baseline;gap:14px;margin-bottom:24px}
  .sec-no{font-family:'IBM Plex Mono',monospace;font-size:13px;color:var(--indigo);font-weight:600}
  h2{font-family:'Source Serif 4',serif;font-weight:600;color:var(--ink);font-size:clamp(23px,3.2vw,32px);letter-spacing:-.01em}
  .lead{font-size:16.5px;line-height:1.75;max-width:68ch;color:var(--body)}
  .subhead{font-family:'Source Serif 4',serif;font-weight:600;font-size:20px;color:var(--ink);margin:38px 0 16px}

  /* ---- overview two-column layout ---- */
  .overview-grid{display:grid;grid-template-columns:1fr 340px;gap:44px;align-items:start}
  .overview-side{position:sticky;top:78px;display:flex;flex-direction:column;gap:18px}
  .side-card{border:1px solid var(--line);border-radius:10px;padding:22px;background:var(--bg-soft)}
  .side-title{font-family:'IBM Plex Mono',monospace;font-size:11px;letter-spacing:.1em;text-transform:uppercase;
    color:var(--indigo);font-weight:600;margin-bottom:14px}
  .side-timeline{border-top:none}
  .side-timeline .tl-row{grid-template-columns:1fr;gap:2px;padding:10px 0;align-items:start}
  .side-timeline .tl-row:first-child{padding-top:0}
  .side-timeline .tl-date{font-size:12.5px}
  .side-timeline .tl-what{font-size:13.5px;line-height:1.35}
  .side-timeline .tl-tag{display:none}
  .side-timeline .note{margin-top:12px}
  .venue-name{font-family:'Source Serif 4',serif;font-weight:600;font-size:16px;color:var(--ink);margin-bottom:4px}
  .venue-addr{display:block;font-size:13px;color:var(--indigo);text-decoration:none;line-height:1.4;margin-bottom:14px}
  .venue-addr:hover{text-decoration:underline}
  .side-map{border-radius:8px;overflow:hidden;border:1px solid var(--line);line-height:0}
  .side-map iframe{width:100%;height:200px;border:0;display:block;filter:grayscale(.2)}
  @media(max-width:900px){
    .overview-grid{grid-template-columns:1fr;gap:28px}
    .overview-side{position:static;flex-direction:column}
  }
  @media(min-width:640px) and (max-width:900px){
    .overview-side{flex-direction:row}
    .side-card{flex:1}
  }
  .lead p+p{margin-top:15px}
  .lead .em{color:var(--ink);font-weight:600}

  /* domains */
  .domains{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px;margin-top:6px}
  .domain{border:1px solid var(--line);border-left:3px solid var(--indigo);border-radius:5px;padding:18px 20px;background:var(--bg-soft)}
  .domain h4{font-family:'Source Serif 4',serif;font-size:16px;color:var(--ink);font-weight:600;margin-bottom:6px}
  .domain p{font-size:13.5px;line-height:1.5;color:var(--dim)}

  /* bottlenecks / CFP */
  .cfp{display:grid;gap:0;border:1px solid var(--line);border-radius:6px;overflow:hidden}
  .row{display:grid;grid-template-columns:52px 1fr;border-bottom:1px solid var(--line)}
  .row:last-child{border-bottom:none}
  .row:hover{background:var(--bg-tint)}
  .row .n{background:var(--navy);color:#fff;font-family:'IBM Plex Mono',monospace;font-weight:600;font-size:14px;display:flex;align-items:flex-start;justify-content:center;padding-top:22px}
  .row .c{padding:20px 24px}
  .row .c h3{font-family:'Source Serif 4',serif;font-weight:600;color:var(--ink);font-size:19px;margin-bottom:6px}
  .row .c h3 .letter{color:var(--indigo);font-weight:700}
  .row .c p{font-size:14.5px;line-height:1.6;color:var(--body)}

  .topics{columns:2;column-gap:44px;max-width:820px;margin-top:4px}
  @media(max-width:640px){.topics{columns:1}}
  .topics li{list-style:none;break-inside:avoid;padding:11px 0 11px 24px;position:relative;border-bottom:1px solid var(--line);font-size:15px;color:var(--body)}
  .topics li::before{content:"›";position:absolute;left:2px;color:var(--indigo);font-weight:700}

  .timeline{border-top:2px solid var(--navy)}
  .tl-row{display:grid;grid-template-columns:170px 1fr auto;gap:20px;align-items:center;padding:16px 0;border-bottom:1px solid var(--line)}
  .tl-row.hl .tl-date{color:#fff;background:var(--indigo);padding:3px 9px;border-radius:3px;display:inline-block}
  .tl-date{font-family:'IBM Plex Mono',monospace;font-size:13.5px;font-weight:600;color:var(--indigo)}
  .tl-what{font-size:16px;font-weight:500;color:var(--ink)}
  .tl-tag{font-family:'IBM Plex Mono',monospace;font-size:11px;color:var(--dim);text-transform:uppercase;letter-spacing:.07em}
  @media(max-width:640px){.tl-row{grid-template-columns:1fr;gap:3px}.tl-tag{display:none}}
  .note{margin-top:16px;font-size:12.5px;color:var(--dim);font-family:'IBM Plex Mono',monospace}

  /* ---- program / schedule ---- */
  .schedule{position:relative;border-left:2px solid var(--line);margin-left:8px}
  .sch-row{display:grid;grid-template-columns:76px 1fr auto;gap:16px;align-items:center;
    padding:13px 0 13px 22px;position:relative}
  .sch-row + .sch-row{border-top:1px solid var(--line)}
  .sch-time{font-family:'IBM Plex Mono',monospace;font-size:14px;font-weight:600;color:var(--ink);font-variant-numeric:tabular-nums}
  .sch-dot{position:absolute;left:-7px;width:12px;height:12px;border-radius:50%;background:#fff;border:2px solid var(--line-2)}
  .sch-title{font-size:15.5px;color:var(--body)}
  .sch-tag{font-family:'IBM Plex Mono',monospace;font-size:10px;letter-spacing:.08em;text-transform:uppercase;
    padding:3px 9px;border-radius:3px;color:var(--indigo);background:var(--bg-tint);border:1px solid var(--line)}
  /* accents by kind */
  .sch-keynote .sch-dot{background:var(--indigo);border-color:var(--indigo)}
  .sch-keynote .sch-title{font-weight:600;color:var(--ink)}
  .sch-oral .sch-dot{background:var(--indigo-2);border-color:var(--indigo-2)}
  .sch-poster .sch-dot{background:#fff;border-color:var(--indigo-2)}
  .sch-panel .sch-dot{background:var(--ink);border-color:var(--ink)}
  .sch-panel .sch-title{font-weight:600;color:var(--ink)}
  .sch-break .sch-title{color:var(--dim);font-style:italic}
  .sch-break .sch-dot{background:var(--bg-soft);border-color:var(--line)}
  @media(max-width:560px){.sch-row{grid-template-columns:60px 1fr;gap:10px}.sch-tag{display:none}}

  .cta-box{background:var(--navy);color:#fff;border-radius:8px;padding:40px;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:26px;position:relative;overflow:hidden}
  .cta-box svg{position:absolute;inset:0;width:100%;height:100%;opacity:.5}
  .cta-box>div{position:relative}
  .cta-box h2{color:#fff}
  .cta-box p{color:#c7d2fe;margin-top:9px;max-width:48ch;font-size:15px}
  .btn{position:relative;display:inline-block;background:var(--indigo-2);color:#fff;text-decoration:none;font-weight:600;font-size:15px;padding:14px 26px;border-radius:5px;transition:background .15s,transform .15s;white-space:nowrap}
  .btn:hover{background:#818cf8;transform:translateY(-1px)}

  /* ---- shared photo + initials placeholder ---- */
  .spk-photo,.org-photo{position:relative;overflow:hidden;background:var(--bg-tint)}
  .spk-photo img,.org-photo img{width:100%;height:100%;object-fit:cover;display:block}
  .spk-ph,.org-ph{display:none;position:absolute;inset:0;align-items:center;justify-content:center;
    font-family:'Source Serif 4',serif;font-weight:600;color:var(--indigo);background:var(--bg-tint)}

  /* ---- keynote speakers ---- */
  .speakers{display:grid;grid-template-columns:1fr;gap:0;border-top:1px solid var(--line)}
  .spk{display:grid;grid-template-columns:132px 1fr;gap:26px;padding:26px 0;border-bottom:1px solid var(--line);align-items:start}
  .spk-photo{width:132px;height:132px;border-radius:6px;flex:none}
  .spk-ph{font-size:34px;border-radius:6px}
  .spk-head{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
  .spk-name{font-family:'Source Serif 4',serif;font-weight:600;font-size:21px;color:var(--ink)}
  .spk-status{font-family:'IBM Plex Mono',monospace;font-size:10.5px;letter-spacing:.08em;text-transform:uppercase;
    padding:3px 9px;border-radius:3px}
  .spk-status.confirmed{background:#dcfce7;color:#166534}
  .spk-status.tentative{background:#f1f0fb;color:var(--indigo);border:1px solid var(--line)}
  .spk-role{font-size:14px;color:var(--indigo);font-weight:500;margin-top:3px}
  .spk-talk{font-family:'Source Serif 4',serif;font-style:italic;font-size:15.5px;color:var(--ink);margin-top:10px}
  .spk-bio{font-size:14.5px;line-height:1.6;color:var(--body);margin-top:10px;max-width:70ch}
  @media(max-width:560px){
    .spk{grid-template-columns:1fr;gap:14px}
    .spk-photo{width:96px;height:96px}.spk-ph{font-size:26px}
  }

  /* ---- organizers ---- */
  .org-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:28px 26px}
  .org{display:flex;flex-direction:column}
  .org-photo{width:100%;aspect-ratio:1/1;border-radius:6px;margin-bottom:14px;border:1px solid var(--line)}
  .org-ph{font-size:40px;border-radius:6px}
  .org-name{font-family:'Source Serif 4',serif;font-weight:600;font-size:17px;color:var(--ink)}
  .org-aff{font-size:13px;color:var(--indigo);font-weight:500;margin-top:2px}
  .org-bio{font-size:13px;line-height:1.55;color:var(--dim);margin-top:8px}
  .contact{margin-top:34px;font-size:14px;color:var(--body)}
  .tagline{margin-top:14px;font-family:'Source Serif 4',serif;font-style:italic;font-size:18px;color:var(--ink);max-width:60ch}

  /* ---- sponsors ---- */
  .sp-tier{margin-bottom:30px}
  .sp-tier-label{font-family:'IBM Plex Mono',monospace;font-size:11px;letter-spacing:.1em;text-transform:uppercase;
    color:var(--dim);margin-bottom:16px;padding-bottom:8px;border-bottom:1px solid var(--line)}
  .sp-row{display:flex;flex-wrap:wrap;gap:20px;align-items:center}
  .sp-logo{display:flex;align-items:center;justify-content:center;min-width:150px;height:84px;padding:16px 26px;
    background:var(--bg-soft);border:1px solid var(--line);border-radius:8px;text-decoration:none;transition:border-color .15s,background .15s}
  .sp-logo:hover{border-color:var(--indigo-2);background:#fff}
  .sp-logo img{max-height:48px;max-width:180px;width:auto;object-fit:contain;display:block}
  .sp-name{font-family:'Source Serif 4',serif;font-weight:600;font-size:18px;color:var(--ink);align-items:center}
  .sponsor-cta{margin-top:8px;font-size:14px;color:var(--body)}
  .sponsor-cta a{color:var(--indigo);text-decoration:none;font-weight:600}
  .sponsor-cta a:hover{text-decoration:underline}

  footer{background:var(--bg-soft);padding:40px 0;font-size:13.5px;color:var(--dim);border-top:1px solid var(--line)}
  footer .wrap{display:flex;flex-wrap:wrap;justify-content:space-between;gap:18px}
  footer a{text-decoration:none}
  footer a:hover{text-decoration:underline}
  .footmark{font-family:'Inter';font-weight:700;color:var(--ink)}
  .foot-brand{display:flex;align-items:flex-start;gap:16px}
  .foot-icon{width:46px;height:46px;flex:none;border-radius:10px}

  @media(prefers-reduced-motion:no-preference){
    .reveal{opacity:0;transform:translateY(12px);transition:opacity .55s ease,transform .55s ease}
    .reveal.in{opacity:1;transform:none}
  }