:root{
    --ink:#1a2436;          /* deep slate ink */
    --ink-soft:#4a5568;     /* muted slate */
    --paper:#f4f6fa;        /* cool slate-white */
    --paper-2:#ffffff;
    --line:#dce2ec;         /* soft slate line */
    --accent:#2563c9;       /* academic royal blue */
    --accent-2:#0f7a98;     /* deep cyan grounding */
    --accent-soft:#e4ecfb;  /* pale blue wash */
    --teal-soft:#e6f1f5;    /* pale cyan wash */
    --shadow:0 1px 0 rgba(26,36,54,.05), 0 10px 30px -18px rgba(26,36,54,.30);
    --maxw:1080px;
    --prose:920px;          /* shared measure so centered text columns align */
  }
  *{box-sizing:border-box;}
  html{scroll-behavior:smooth;scroll-padding-top:88px;}
  body{
    margin:0;
    background:var(--paper);
    color:var(--ink);
    font-family:'Inter',system-ui,sans-serif;
    font-size:17px;
    line-height:1.65;
    -webkit-font-smoothing:antialiased;
  }
  a{color:var(--accent-2);text-decoration:none;}
  a:hover{text-decoration:underline;}
  h1,h2,h3,h4{font-family:'Sora',sans-serif;line-height:1.15;color:var(--ink);}

  /* ---------- nav ---------- */
  nav{
    position:sticky;top:0;z-index:50;
    background:rgba(246,244,238,.88);
    backdrop-filter:blur(10px);
    border-bottom:1px solid var(--line);
  }
  .nav-inner{
    max-width:var(--maxw);margin:0 auto;padding:17px 24px;
    display:flex;align-items:center;justify-content:space-between;gap:16px;
  }
  .brand{
    font-family:'JetBrains Mono',monospace;font-weight:600;font-size:16px;
    letter-spacing:.04em;color:var(--ink);text-transform:uppercase;
    display:flex;align-items:center;gap:10px;
  }
  .brand .dot{width:13px;height:13px;border-radius:50%;background:var(--accent);
    box-shadow:0 0 0 5px var(--accent-soft);}
  /* brand is a link home now — keep it looking like the wordmark, not a link */
  a.brand{text-decoration:none;}
  a.brand:hover{text-decoration:none;color:var(--accent);}
  .nav-links{display:flex;gap:6px;flex-wrap:wrap;}
  .nav-links a{
    font-size:16.5px;font-weight:500;color:var(--ink-soft);
    padding:8px 14px;border-radius:999px;transition:.15s;
  }
  .nav-links a:hover{background:var(--accent-soft);color:var(--accent);text-decoration:none;}
  .nav-toggle{display:none;background:none;border:1px solid var(--line);border-radius:8px;
    padding:6px 10px;font-size:18px;cursor:pointer;color:var(--ink);}

  /* ---------- hero ---------- */
  header.hero{
    /* full-bleed cover photo; the light gradient keeps the dark text readable
       and fades the image into the page background at the bottom */
    max-width:none;margin:0 auto;padding:96px 24px 72px;
    position:relative;text-align:center;
    background-image:
      linear-gradient(180deg,
        rgba(244,246,250,.72) 0%,
        rgba(244,246,250,.80) 45%,
        rgba(244,246,250,.95) 88%,
        rgba(244,246,250,1) 100%),
      url('cover.jpg');
    background-size:cover;
    background-position:center 42%;
  }
  /* hero content stays on the normal page measure even though the photo is full width */
  header.hero > *{max-width:var(--maxw);margin-left:auto;margin-right:auto;}
  .hero h1{
    font-size:clamp(27px,4.2vw,48px);font-weight:800;letter-spacing:-.02em;
    margin:0 auto 6px;max-width:22ch;
  }
  .hero h1 .g2a{color:var(--accent);}
  .hero .sub{
    font-size:clamp(17px,2.1vw,20px);color:var(--ink-soft);font-weight:500;
    max-width:64ch;margin:18px auto 0;font-family:'Sora',sans-serif;
  }

  /* ---------- hero facts (time & location) ---------- */
  .hero-facts{
    display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));
    gap:14px;margin:34px auto 0;max-width:900px;text-align:left;
  }
  .fact{
    background:var(--paper-2);border:1px solid var(--line);border-radius:14px;
    padding:16px 18px;box-shadow:var(--shadow);
  }
  .fact .lbl{
    font-family:'JetBrains Mono',monospace;font-size:11px;font-weight:600;
    letter-spacing:.12em;text-transform:uppercase;color:var(--accent);
    display:block;margin-bottom:6px;
  }
  .fact .val{font-family:'Sora',sans-serif;font-weight:600;font-size:16.5px;color:var(--ink);display:block;line-height:1.3;}
  .fact .note{font-size:13.5px;color:var(--ink-soft);display:block;margin-top:5px;line-height:1.45;}
  .cta-row{display:flex;flex-wrap:wrap;gap:12px;margin-top:30px;justify-content:center;}
  .btn{
    font-family:'Sora',sans-serif;font-weight:600;font-size:15px;
    padding:12px 22px;border-radius:10px;border:1.5px solid var(--ink);
    transition:.16s;cursor:pointer;display:inline-flex;align-items:center;gap:8px;
  }
  .btn-primary{background:var(--accent);border-color:var(--accent);color:#fff;}
  .btn-primary:hover{background:#1d4fa3;border-color:#1d4fa3;color:#fff;text-decoration:none;}
  .btn-ghost{background:transparent;color:var(--ink);}
  .btn-ghost:hover{background:var(--ink);color:var(--paper);text-decoration:none;}
  .btn .icon{width:19px;height:19px;flex:none;}

  /* ---------- section frame ---------- */
  section{max-width:var(--maxw);margin:0 auto;padding:56px 24px;border-top:1px solid var(--line);}
  /* every block inside a section shares the prose column, so sub-heads, lists,
     grids and tables all start on the same left edge as the body text */
  section > *{max-width:var(--prose);margin-left:auto;margin-right:auto;}
  /* Sized to the prose column and shifted left by exactly the number gutter
     (18px + 14px gap), so the TITLE — not the number — sits on the paragraph's
     left edge. The shift collapses to 0 once the viewport is too narrow to
     hang the number in the margin. */
  .sec-head{
    display:flex;align-items:baseline;gap:14px;
    width:min(100%,var(--prose));margin:0 auto 30px;
    position:relative;
    left:calc(-1 * min(32px, max(0px, (100% - var(--prose)) / 2)));
  }
  .sec-num{
    font-family:'JetBrains Mono',monospace;font-size:13px;font-weight:600;
    color:var(--accent);letter-spacing:.05em;
    flex:0 0 18px;
  }
  .sec-head h2{font-size:clamp(23px,3vw,32px);font-weight:700;letter-spacing:-.015em;margin:0;}
  /* body prose sits in a centered column; text itself stays flush left */
  .lead{font-size:18px;color:var(--ink);max-width:var(--prose);margin-left:auto;margin-right:auto;}
  .prose{max-width:var(--prose);margin-left:auto;margin-right:auto;}
  p{margin:0 0 16px;}
  .sub-head{
    font-family:'Sora',sans-serif;font-size:21px;font-weight:600;
    letter-spacing:-.01em;color:var(--ink);line-height:1.2;
    margin:40px auto 18px;
    text-decoration:underline;text-decoration-thickness:1.5px;text-underline-offset:6px;
    text-decoration-color:var(--line);
  }

  /* ---------- callout ---------- */
  .callout{
    border-left:3px solid var(--accent);background:var(--accent-soft);
    border-radius:0 12px 12px 0;padding:18px 22px;margin:26px auto 0;max-width:var(--prose);
  }
  .callout .k{
    font-family:'JetBrains Mono',monospace;font-size:11.5px;font-weight:600;
    letter-spacing:.1em;text-transform:uppercase;color:var(--accent);display:block;margin-bottom:6px;
  }
  .callout p{margin:0;font-size:16.5px;}

  /* ---------- topics list ---------- */
  /* bullet sits on the prose edge, in line with the sub-head above it;
     text is indented and wrapped lines hang to that same indent */
  .topic-list{list-style:none;padding-left:0;margin:0 auto;max-width:var(--prose);}
  .topic-list li{
    position:relative;padding-left:26px;
    margin-bottom:16px;font-size:16.5px;line-height:1.7;color:var(--ink);
  }
  .topic-list li:last-child{margin-bottom:0;}
  .topic-list li::before{content:"•";position:absolute;left:3px;top:0;color:var(--ink-soft);}
  .topic-list li b{font-weight:700;}

  /* ---------- schedule ---------- */
  .sched{border:1px solid var(--line);border-radius:14px;overflow:hidden;background:var(--paper-2);box-shadow:var(--shadow);}
  .sched-row{display:grid;grid-template-columns:170px 1fr;border-top:1px solid var(--line);}
  .sched-row:first-child{border-top:none;}
  .sched-row .t{
    font-family:'JetBrains Mono',monospace;font-size:13.5px;font-weight:500;
    color:var(--accent-2);padding:16px 18px;background:var(--teal-soft);
    display:flex;align-items:center;
  }
  .sched-row .d{padding:16px 18px;font-size:16px;}
  .sched-row .d b{font-weight:600;}
  .sched-tag{
    font-family:'JetBrains Mono',monospace;font-size:11.5px;letter-spacing:.04em;
    text-transform:uppercase;color:var(--accent);font-weight:600;
    display:block;margin-bottom:2px;
  }
  .sched-note{font-size:14px;color:var(--ink-soft);margin-top:18px;font-style:italic;text-align:center;}

  /* ---------- organizers ---------- */
  /* same figure treatment as speakers, 5 across since there are fourteen */
  .org-grid{grid-template-columns:repeat(5,1fr);gap:32px 20px;}
  @media(max-width:960px){.org-grid{grid-template-columns:repeat(3,1fr);}}
  @media(max-width:640px){.org-grid{grid-template-columns:repeat(2,1fr);}}
  /* stand-in for the few organizers whose photo we do not have yet */
  .ph-fallback{
    width:156px;height:156px;border-radius:50%;margin:0 auto 16px;
    display:flex;align-items:center;justify-content:center;
    font-family:'Sora',sans-serif;font-weight:700;font-size:40px;color:#fff;
    background:linear-gradient(135deg,var(--accent),#5b8de8);
  }
  .spk:nth-child(even) .ph-fallback{background:linear-gradient(135deg,var(--accent-2),#3ba6c2);}
  /* ---------- invited speakers ---------- */
  .spk-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:34px 24px;margin-top:10px;}
  section > .spk-grid{max-width:none;}
  @media(max-width:860px){.spk-grid{grid-template-columns:repeat(2,1fr);}}
  @media(max-width:460px){.spk-grid{grid-template-columns:1fr;}}
  .spk{margin:0;text-align:center;}
  .spk img{
    width:156px;height:156px;border-radius:50%;object-fit:cover;
    display:block;margin:0 auto 16px;background:var(--paper-2);
  }
  .spk .nm{
    display:block;font-family:'Sora',sans-serif;font-size:18px;font-weight:600;
    color:var(--ink);letter-spacing:-.01em;margin-bottom:4px;
  }
  .spk .aff{display:block;font-size:15px;color:var(--ink-soft);line-height:1.4;}

  /* ---------- call for papers ---------- */
  .cfp-box{
    background:var(--ink);color:var(--paper);border-radius:16px;padding:30px 32px;
    margin-top:20px;
  }
  .cfp-box h3{color:#fff;font-size:21px;margin:0 0 12px;}
  .cfp-box p{color:#d3ddea;margin:0 0 12px;}
  .cfp-box p:last-child{margin-bottom:0;}
  .cfp-box a{color:#9dc1f5;}
  .track-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px;margin-top:20px;}
  .track{
    background:var(--paper-2);border:1px solid var(--line);border-radius:14px;
    padding:20px 22px;box-shadow:var(--shadow);
  }
  .track .tag{
    font-family:'JetBrains Mono',monospace;font-size:11px;font-weight:600;
    letter-spacing:.08em;text-transform:uppercase;color:#fff;background:var(--accent);
    border-radius:999px;padding:4px 11px;display:inline-block;margin-bottom:11px;
  }
  .track:nth-child(2) .tag{background:var(--accent-2);}
  .track h4{font-size:17.5px;margin:0 0 7px;font-weight:600;}
  .track p{font-size:15px;color:var(--ink-soft);margin:0 0 10px;line-height:1.55;}
  .track .len{
    font-family:'JetBrains Mono',monospace;font-size:13px;color:var(--accent-2);font-weight:600;
  }

  .dates-wrap{border:1px solid var(--line);border-radius:14px;overflow:hidden;
    background:var(--paper-2);box-shadow:var(--shadow);}
  table.dates{width:100%;border-collapse:collapse;}
  table.dates th{
    font-family:'JetBrains Mono',monospace;font-size:11.5px;font-weight:600;
    letter-spacing:.1em;text-transform:uppercase;color:var(--accent);
    text-align:left;padding:13px 20px;background:var(--accent-soft);
    border-bottom:1px solid var(--line);
  }
  table.dates td{padding:14px 20px;border-bottom:1px solid var(--line);font-size:16px;}
  table.dates tr:last-child td{border-bottom:none;}
  table.dates td.dt{
    font-family:'JetBrains Mono',monospace;font-size:14.5px;font-weight:500;color:var(--accent-2);
    white-space:nowrap;
  }
  table.dates tr.hl td{background:var(--teal-soft);font-weight:600;}
  .dates-note{font-size:14px;color:var(--ink-soft);margin-top:14px;font-style:italic;text-align:center;}

  /* ---------- footer ---------- */
  footer{border-top:1px solid var(--line);background:var(--paper-2);}
  .foot-inner{max-width:var(--maxw);margin:0 auto;padding:38px 24px;
    display:flex;flex-wrap:wrap;justify-content:space-between;gap:20px;align-items:center;}
  .foot-inner .brand{font-size:15px;}
  .foot-inner p{font-size:16px;color:var(--ink-soft);margin:0;}
  .sponsor{display:flex;align-items:center;gap:12px;font-size:16px;color:var(--ink-soft);}
  /* wordmark inherits colour via currentColor on its paths */
  .lambda-logo{width:auto;display:block;}
  .sponsor .lambda-logo{height:38px;color:var(--ink);}
  .sponsor a{display:inline-flex;color:var(--ink);text-decoration:none;transition:color .16s;}
  .sponsor a:hover{color:var(--accent);text-decoration:none;}

  /* ---------- sponsor section ---------- */
  .sponsor-block{text-align:center;margin-top:6px;}
  .sponsor-mark{display:inline-block;color:var(--ink);transition:color .16s;}
  .sponsor-mark:hover{color:var(--accent);text-decoration:none;}
  .sponsor-mark .lambda-logo{height:66px;}
  .sponsor-block p{margin:28px auto 0;font-size:16.5px;color:var(--ink-soft);max-width:var(--prose);text-align:left;}
  @media(max-width:600px){.sponsor-mark .lambda-logo{height:48px;}}

  /* ---------- responsive ---------- */
  @media(max-width:720px){
    .nav-links{
      display:none;position:absolute;top:100%;left:0;right:0;
      flex-direction:column;background:var(--paper);border-bottom:1px solid var(--line);
      padding:10px 16px;gap:2px;
    }
    .nav-links.open{display:flex;}
    .nav-toggle{display:block;}
    .sched-row{grid-template-columns:1fr;}
    .sched-row .t{background:var(--teal-soft);}
    header.hero{padding:52px 24px 40px;}
    .dates-wrap{overflow-x:auto;}
    .cfp-box{padding:24px 22px;}
  }

  /* ---------- multi-page nav ---------- */
  /* the current page's pill stays filled, including under :hover */
  .nav-links a.active,
  .nav-links a.active:hover{background:var(--accent);color:#fff;}
  /* a page whose first element is a section sits right under the nav bar,
     so drop the rule that would double up with the nav's bottom border */
  main > section:first-child{border-top:none;padding-top:64px;}