/* Shared Salesforce AI Research design system for Overview, Engineer, and TrainForge. */
  :root{
    color-scheme:light;
    --font-body:'DM Sans',system-ui,-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;
    --font-display:var(--font-body);
    --bg-primary:#f8fbfe;
    --bg-secondary:#ffffff;
    --bg-tertiary:#eef5fc;
    --sf-blue:#0176D3;
    --sf-blue-bright:#1B96FF;
    --sf-blue-deep:#0B5CAB;
    --sf-navy:#032D60;
    --sf-cloud:#EAF5FE;
    --sf-teal:#0B827C;
    --sf-green:#2E844A;
    --sf-orange:#DD7A01;
    --sf-orange-text:#A96404;
    --text-primary:#243b53;
    --text-secondary:#496078;
    --text-muted:#5e7288;
    --border-color:#dbe7f2;
    --gradient-1:linear-gradient(135deg,#1B96FF 0%,#0B5CAB 100%);
    --gradient-deep:linear-gradient(135deg,#0176D3 0%,#032D60 100%);
    --shadow-sm:0 1px 2px rgba(3,45,96,.05);
    --shadow-md:0 4px 12px rgba(3,45,96,.08);
    --shadow-lg:0 12px 40px rgba(3,45,96,.12);
  }
  *{margin:0;padding:0;box-sizing:border-box}
  html{scroll-behavior:smooth}
  body{
    font-family:var(--font-body);
    background:var(--bg-primary);
    color:var(--text-primary);
    line-height:1.7;
  }
  .bg-pattern{
    position:fixed;inset:0;z-index:-1;pointer-events:none;
    background-image:
      radial-gradient(circle at 18% 40%, rgba(1,118,211,.05) 0%, transparent 50%),
      radial-gradient(circle at 85% 15%, rgba(27,150,255,.05) 0%, transparent 45%);
  }
  .container{max-width:1120px;margin:0 auto;padding:0 2rem}
  a{color:var(--sf-blue-deep)}
  code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.86em;background:var(--bg-tertiary);border:1px solid var(--border-color);border-radius:6px;padding:.1em .4em;color:var(--sf-navy)}

  /* ---------- hero ---------- */
  .hero{
    display:flex;flex-direction:column;align-items:center;text-align:center;
    padding:4rem 2rem 3rem;max-width:1120px;margin:0 auto;
  }
  .hero-logo{height:64px;width:auto;margin-bottom:1.4rem;filter:drop-shadow(0 10px 24px rgba(1,118,211,.25))}
  .hero-eyebrow{
    font-size:.75rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase;
    color:var(--sf-blue-deep);margin-bottom:1.4rem;padding:.4rem .85rem;border:1px solid #cde6fa;border-radius:999px;background:var(--sf-cloud);
  }
  .hero h1{
    font-family:var(--font-display);
    font-size:clamp(2.5rem,6vw,4.5rem);line-height:1.1;font-weight:700;color:var(--sf-navy);
    margin-bottom:1rem;letter-spacing:-.045em;
  }
  .hero h2{
    font-family:var(--font-display);
    font-size:clamp(1.15rem,2.4vw,1.5rem);font-weight:500;line-height:1.5;color:var(--text-secondary);
    max-width:780px;margin-bottom:1.6rem;
  }
  .hero-description{
    font-size:1.06rem;color:var(--text-secondary);max-width:730px;margin-bottom:2rem;line-height:1.8;
  }
  .highlight-pills{display:flex;flex-direction:column;align-items:center;gap:.7rem;margin-bottom:2.2rem}
  .pill-row{display:flex;flex-wrap:wrap;gap:.7rem;justify-content:center}
  .pill{padding:.48rem 1.05rem;border-radius:50px;font-size:.85rem;font-weight:600;display:inline-flex;align-items:center;gap:.45rem;line-height:1.3}
  .pill.speed{background:rgba(46,132,74,.09);color:var(--sf-green);border:1px solid rgba(46,132,74,.3)}
  .pill.memory{background:rgba(11,130,124,.09);color:var(--sf-teal);border:1px solid rgba(11,130,124,.3)}
  .pill.exact{background:rgba(1,118,211,.08);color:var(--sf-blue-deep);border:1px solid rgba(1,118,211,.3)}
  .pill.oss{background:rgba(221,122,1,.09);color:var(--sf-orange-text);border:1px solid rgba(221,122,1,.35)}
  .pill.scope{background:rgba(3,45,96,.07);color:var(--sf-navy);border:1px solid rgba(3,45,96,.28)}
  .pill.search{background:rgba(88,103,232,.08);color:#3B4DB8;border:1px solid rgba(88,103,232,.3)}
  .pill.pandas{background:rgba(90,27,169,.07);color:#5A1BA9;border:1px solid rgba(90,27,169,.3)}
  .btn{
    padding:.8rem 1.6rem;border-radius:8px;font-size:.95rem;font-weight:600;text-decoration:none;
    display:inline-flex;align-items:center;gap:.5rem;transition:all .25s ease;
  }
  .btn-primary{background:var(--sf-blue);color:#fff}
  .btn-primary:hover{background:var(--sf-blue-deep);transform:translateY(-2px);box-shadow:0 10px 28px rgba(1,118,211,.35)}
  .btn-secondary{background:var(--bg-secondary);color:var(--text-primary);border:1px solid var(--border-color);box-shadow:var(--shadow-sm)}
  .btn-secondary:hover{background:var(--bg-tertiary);transform:translateY(-2px)}

  /* authors */
  .authors{display:flex;flex-wrap:wrap;gap:1.6rem;justify-content:center;margin-bottom:.9rem}
  .author{display:flex;flex-direction:column;align-items:center;text-decoration:none;color:var(--text-primary);transition:transform .25s ease}
  .author:hover{transform:translateY(-3px)}
  .author-img{
    width:64px;height:64px;border-radius:50%;border:3px solid var(--bg-secondary);
    margin-bottom:.5rem;box-shadow:var(--shadow-md);object-fit:cover;background:var(--gradient-1);
    display:block;
  }
  .author-fallback{
    display:none;align-items:center;justify-content:center;
    color:#fff;font-weight:700;font-size:1.35rem;letter-spacing:.02em;
  }
  .author-name{font-size:.92rem;font-weight:600}
  .affiliation{color:var(--sf-blue-deep);font-size:.98rem;font-weight:600;margin-top:.4rem}
  .hero-meta{color:var(--text-muted);font-size:.85rem;margin-top:.3rem}
  /* MARKETING: add a "Corresponding author: name@salesforce.com" line under .affiliation if desired */

  /* ---------- sections ---------- */
  section{padding:3.6rem 0}
  .section-title{
    font-family:var(--font-display);font-size:1.9rem;font-weight:600;
    text-align:left;margin-bottom:2rem;color:var(--sf-navy);letter-spacing:-.025em;
  }
  .section-title::after{
    content:'';display:block;width:60px;height:4px;background:var(--gradient-1);
    margin:.9rem 0 0;border-radius:2px;
  }
  .card{
    background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:16px;
    padding:2rem;box-shadow:var(--shadow-sm);
  }
  .abstract{font-size:1.04rem;line-height:1.9;color:var(--text-secondary)}
  .abstract strong{color:var(--text-primary)}

  /* takeaways */
  .results-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:1.4rem;margin-bottom:1.8rem}
  .result-card{
    background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:16px;
    padding:1.7rem 1.4rem;text-align:center;box-shadow:var(--shadow-sm);
  }
  .result-value{
    font-family:var(--font-display);font-size:2.9rem;font-weight:700;line-height:1.15;
    background:var(--gradient-deep);-webkit-background-clip:text;background-clip:text;
    -webkit-text-fill-color:transparent;color:transparent;
  }
  .result-label{font-size:.98rem;font-weight:600;margin-top:.4rem}
  .result-detail{font-size:.83rem;color:var(--text-muted);margin-top:.2rem;line-height:1.5}
  .takeaway-box{
    background:linear-gradient(135deg,rgba(1,118,211,.06) 0%,rgba(3,45,96,.06) 100%);
    border:1px solid rgba(1,118,211,.22);border-radius:16px;padding:1.8rem 2rem;
  }
  .takeaway-box h4{font-size:1rem;font-weight:700;color:var(--sf-blue-deep);margin-bottom:.7rem;display:flex;align-items:center;gap:.5rem}
  .takeaway-box ul{margin-left:1.15rem}
  .takeaway-box li{font-size:.97rem;color:var(--text-secondary);line-height:1.75;margin-bottom:.5rem}
  .takeaway-box li strong{color:var(--text-primary)}
  .takeaway-box p{font-size:.95rem;color:var(--text-secondary)}

  /* breadth block */
  .breadth{
    background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:16px;
    padding:1.8rem 2rem;margin-bottom:1.4rem;box-shadow:var(--shadow-sm);
  }
  .breadth h3{font-family:var(--font-display);font-size:1.35rem;font-weight:600;color:var(--sf-navy);margin-bottom:.4rem}
  .breadth>p{color:var(--text-secondary);font-size:.97rem;max-width:780px}
  .domain-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1rem;margin:1.2rem 0 1.4rem}
  .domain{background:var(--bg-tertiary);border:1px solid var(--border-color);border-radius:12px;padding:1rem 1.1rem;display:flex;flex-direction:column}
  .domain-icon{font-size:1.35rem;margin-bottom:.35rem}
  .domain b{font-size:.98rem;color:var(--text-primary);margin-bottom:.15rem}
  .domain span:last-child{font-size:.84rem;color:var(--text-secondary);line-height:1.5}
  .breadth-stats{display:flex;flex-wrap:wrap;gap:.6rem 2.4rem;border-top:1px solid var(--border-color);padding-top:1.1rem}
  .breadth-stats div{display:flex;align-items:baseline;gap:.45rem}
  .breadth-stats b{font-family:var(--font-display);font-size:1.7rem;font-weight:700;color:var(--sf-blue-deep)}
  .breadth-stats span{font-size:.88rem;color:var(--text-secondary)}

  /* method cards */
  .contributions-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1.4rem;margin-top:2rem}
  .contribution-card{
    background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:16px;
    padding:1.7rem;transition:all .3s ease;box-shadow:var(--shadow-sm);
  }
  .contribution-card:hover{border-color:var(--sf-blue);transform:translateY(-4px);box-shadow:var(--shadow-lg)}
  .contribution-icon{
    width:48px;height:48px;border-radius:13px;display:flex;align-items:center;justify-content:center;
    font-size:1.35rem;margin-bottom:.9rem;
  }
  .contribution-card:nth-child(1) .contribution-icon{background:rgba(1,118,211,.1)}
  .contribution-card:nth-child(2) .contribution-icon{background:rgba(46,132,74,.1)}
  .contribution-card:nth-child(3) .contribution-icon{background:rgba(11,130,124,.1)}
  .contribution-card:nth-child(4) .contribution-icon{background:rgba(221,122,1,.1)}
  .contribution-card h3{font-size:1.04rem;font-weight:700;margin-bottom:.5rem}
  .contribution-card p{font-size:.92rem;color:var(--text-secondary);line-height:1.65}
  .footnote{font-size:.85rem;color:var(--text-muted);font-style:italic;margin-top:1.8rem;text-align:center;max-width:760px;margin-left:auto;margin-right:auto;line-height:1.6}


  /* technical-details dropdowns */
  details.tech{margin:1.3rem 0 .3rem;border:1px solid var(--border-color);border-radius:12px;background:var(--bg-tertiary);overflow:hidden}
  details.tech summary{cursor:pointer;list-style:none;display:flex;align-items:center;gap:.7rem;padding:.9rem 1.2rem;font-weight:700;font-size:.95rem;color:var(--sf-blue-deep);user-select:none}
  details.tech summary::-webkit-details-marker{display:none}
  details.tech summary::before{content:'';flex:none;width:8px;height:8px;border-right:2px solid var(--sf-blue-deep);border-bottom:2px solid var(--sf-blue-deep);transform:rotate(-45deg);transition:transform .2s;margin:0 .1rem 0 .2rem}
  details.tech[open] summary::before{transform:rotate(45deg);margin-top:-.25rem}
  details.tech summary:hover{background:rgba(1,118,211,.06)}
  details.tech .tech-body{padding:.3rem 1.5rem 1.4rem;font-size:1rem;color:var(--text-primary);border-top:1px solid var(--border-color);background:var(--bg-secondary);line-height:1.75}
  details.tech h5{font-family:'Source Serif 4',Georgia,serif;font-size:1.08rem;font-weight:600;color:var(--sf-navy);margin:1.3rem 0 .5rem;padding-bottom:.3rem;border-bottom:1px solid var(--border-color)}
  details.tech p{margin:0 0 .85rem}
  details.tech ul{margin:0 0 .85rem 1.25rem}
  details.tech li{margin-bottom:.45rem}
  details.tech .tech-body code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.86em;background:#eef3f9;border:0;border-radius:5px;padding:.08em .38em;color:#0b3d7a}
  details.tech pre{background:#f7f9fc;border:1px solid var(--border-color);color:#1e293b;border-radius:10px;padding:1rem 1.15rem;font-size:.86rem;line-height:1.6;overflow-x:auto;margin:.5rem 0 1rem}
  details.tech .tech-body pre code{background:none;border:0;border-radius:0;padding:0;color:inherit;font-size:inherit;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
  details.tech var{font-family:'Source Serif 4',Georgia,serif;font-style:italic;font-size:1.06em;color:var(--sf-navy)}
  details.tech .math{display:block;text-align:center;font-family:'Source Serif 4',Georgia,serif;font-size:1.15rem;color:var(--text-primary);margin:.7rem 0 1rem;line-height:1.7}
  details.tech .frac{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;margin:0 .3em;line-height:1.3}
  details.tech .frac>span:first-child{border-bottom:1px solid currentColor;padding:0 .35em .12em}
  details.tech .frac>span:last-child{padding:.12em .35em 0}

  /* findings */
  .disc{margin-bottom:2rem}
  .disc-head{display:flex;align-items:flex-start;gap:1rem;margin-bottom:.9rem}
  .disc-badge{
    flex:none;width:44px;height:44px;border-radius:12px;background:var(--gradient-1);
    display:flex;align-items:center;justify-content:center;font-weight:700;color:#fff;font-size:1.1rem;
    box-shadow:0 6px 16px rgba(1,118,211,.3);
  }
  .disc-kicker{font-size:.76rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--sf-blue-deep)}
  .disc h3{font-family:var(--font-display);font-size:1.5rem;font-weight:600;margin:.1em 0 0;color:var(--sf-navy)}
  .disc p{color:var(--text-secondary);font-size:.99rem;margin-bottom:1em}
  .disc p strong{color:var(--text-primary)}
  .badge-row{margin:.2rem 0 1.1rem}
  .opt-head{
    display:flex;align-items:center;gap:.8rem;flex-wrap:wrap;
    margin:1.9rem 0 .7rem;padding-top:1.5rem;border-top:1px solid var(--border-color);
    font-family:var(--font-display);font-size:1.2rem;font-weight:600;color:var(--sf-navy);
  }
  .opt-head span{
    font-family:var(--font-body);font-size:.72rem;font-weight:700;letter-spacing:.12em;
    text-transform:uppercase;color:var(--sf-blue-deep);background:rgba(1,118,211,.08);
    border:1px solid rgba(1,118,211,.25);border-radius:999px;padding:.2rem .7rem;white-space:nowrap;
  }
  .mini-pill{
    display:inline-block;font-size:.78rem;font-weight:700;border-radius:999px;padding:.22rem .8rem;margin:.15rem .4rem .15rem 0;
  }
  .mini-pill.blue{background:rgba(1,118,211,.08);color:var(--sf-blue-deep);border:1px solid rgba(1,118,211,.3)}
  .mini-pill.green{background:rgba(46,132,74,.09);color:var(--sf-green);border:1px solid rgba(46,132,74,.3)}
  .pr-row{margin-top:1.4rem;padding-top:1.2rem;border-top:1px solid var(--border-color);display:flex;align-items:center;gap:1rem;flex-wrap:wrap}
  .pr-row .btn{padding:.6rem 1.2rem;font-size:.88rem}
  .pr-row small{color:var(--text-muted)}

  /* figures / charts */
  figure.chart{margin:1.6rem 0 .4rem;text-align:center;overflow-x:auto}
  figure.chart svg{width:100%;min-width:470px;max-width:560px;height:auto}
  figure.chart figcaption{font-size:.84rem;color:var(--text-muted);max-width:600px;margin:.6rem auto 0;line-height:1.55;text-align:center}
  figure.chart figcaption strong{color:var(--text-secondary)}
  figure.chart svg path[fill]:hover{opacity:.85}
  .legend{display:flex;gap:1.4rem;justify-content:center;flex-wrap:wrap;margin:1rem 0 -.4rem;font-size:.85rem;color:var(--text-secondary)}
  .legend i{display:inline-block;width:12px;height:12px;border-radius:3px;margin-right:.45rem;vertical-align:-1px}
  figure.diagram{margin:1.8rem 0 .3rem;overflow-x:auto}
  figure.diagram svg{width:100%;min-width:780px;height:auto}
  figure.diagram figcaption{font-size:.84rem;color:var(--text-muted);margin-top:.6rem;text-align:center}
  .duo{display:grid;grid-template-columns:1fr 1fr;gap:.6rem 1.6rem;align-items:start}
  .duo figure.chart svg{min-width:430px}
  @media(max-width:820px){.duo{grid-template-columns:1fr}}

  /* Research demos: shared player styling for Engineer and TrainForge. */
  .video-section{background:rgba(234,245,254,.4)}
  .video-heading{display:flex;align-items:baseline;justify-content:space-between;flex-wrap:wrap;gap:1rem;margin-bottom:2rem}
  .video-heading .section-title{margin-bottom:0}
  .video-duration{font-size:.875rem;color:var(--text-secondary)}
  .video-frame{overflow:hidden;border:1px solid var(--border-color);border-radius:16px;background:var(--sf-navy);box-shadow:var(--shadow-md)}
  .video-frame video{display:block;width:100%;height:auto;aspect-ratio:16 / 9;background:var(--sf-navy)}

  /* footer */
  footer{
    padding:2.6rem 2rem;text-align:center;border-top:1px solid var(--border-color);
    color:var(--text-muted);font-size:.87rem;background:var(--bg-tertiary);
  }
  footer img{height:34px;width:auto;margin-bottom:.8rem;opacity:.95}
  footer p{max-width:720px;margin:0 auto .5rem;line-height:1.65}
  footer a{color:var(--sf-blue-deep);text-decoration:none}
  footer a:hover{text-decoration:underline}

  @media(max-width:600px){
    .hero{padding:3rem 1.2rem 2.6rem}
    section{padding:2.6rem 0}
    .container{padding:0 1.2rem}
  }

  /* Family navigation: the same brand and page links on every route. */
  .site-nav{
    position:sticky;top:0;z-index:20;display:flex;align-items:center;justify-content:space-between;gap:1rem;
    padding:.8rem max(2rem,calc((100vw - 1056px)/2));background:rgba(255,255,255,.96);
    backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--border-color);
  }
  .site-nav-brand{display:inline-flex;align-items:center;gap:.75rem;color:var(--sf-navy);text-decoration:none;white-space:nowrap}
  .site-nav-brand img{height:34px;width:auto}
  .site-nav-wordmark{display:flex;flex-direction:column;line-height:1.4}
  .site-nav-wordmark strong{font-size:.94rem;font-weight:700;letter-spacing:-.025em}
  .site-nav-wordmark small{font-size:.75rem;color:var(--text-secondary)}
  .site-nav-links{display:flex;gap:.35rem;align-items:center;min-width:0;max-width:100%;overflow-x:auto;scrollbar-width:thin}
  .site-nav-links a{font-size:.875rem;font-weight:600;color:var(--text-secondary);text-decoration:none;padding:.5rem .9rem;border-radius:8px;white-space:nowrap;transition:background .2s ease,color .2s ease}
  .site-nav-links a:hover{color:var(--sf-blue-deep);background:var(--bg-tertiary)}
  .site-nav-links a[aria-current=page]{color:var(--sf-blue-deep);background:var(--sf-cloud);box-shadow:inset 0 -2px 0 var(--sf-blue)}
  @media(max-width:900px){
    .site-nav{padding:.75rem 1.25rem;flex-wrap:wrap;gap:.75rem}
    .site-nav-links{width:100%;gap:.4rem}
    .site-nav-links a{flex:1;text-align:center;padding:.4rem .6rem}
  }
  @media(max-width:640px){
    .site-nav-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}
  }

  /* ---- umbrella page: editorial hero, section nav, question cards, stepper, switcher, motion ---- */
  :root{--nav-h:74px;--subnav-h:61px;--board-accent:var(--sf-blue)}
  .hero-ed{background:var(--bg-secondary);text-align:left}
  .hero-ed-inner{max-width:1120px;margin:0 auto;padding:2.25rem 2.625rem 1.8125rem}
  .kicker{font-size:.75rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--sf-blue-deep)}
  .byline{font-size:.9rem;color:var(--text-secondary);margin-top:.75rem;line-height:1.7}
  .byline a{color:var(--text-primary);font-weight:600;text-decoration:none}
  .byline a:hover{color:var(--sf-blue-deep);text-decoration:underline}
  .byline-row{display:block}
  .byline-org{color:var(--text-muted);font-size:.84rem;margin-top:.15rem}
  .team{padding:3.2rem 0 3.6rem}
  .team-block{text-align:center}
  .team .authors{gap:1.2rem 2.4rem;margin:1.3rem 0 0}
  .team .byline{font-size:.95rem;margin-top:.9rem}
  .hero-ed h1{font-family:var(--font-display);font-size:2.625rem;font-weight:700;color:var(--sf-navy);line-height:1.12;letter-spacing:-.045em;margin:.75rem 0 0}
  .hero-title-row{display:flex;align-items:center;justify-content:space-between;gap:1.5rem;padding-bottom:1.625rem;border-bottom:1px solid var(--border-color)}
  .hero-title-row > div{min-width:0}
  .hero-mascots{display:block;width:225px;flex:0 0 225px;height:auto;object-fit:contain}
  .hero-title-row.no-art .hero-mascots{display:none}
  .hero-ed .hero-eyebrow{font-size:.75rem;line-height:1.5;letter-spacing:.11em;color:var(--sf-blue);margin:0;padding:0;border:0;border-radius:0;background:none}
  .hero-ed .deck{font-family:var(--font-body);font-size:1rem;line-height:1.75;color:var(--text-secondary)}
  .hero-ed .deck strong{color:var(--sf-navy);font-weight:600}
  .hero-ed .hero-question{max-width:800px;margin:1.6875rem 0 1.5625rem;font-size:1.5625rem;line-height:1.5;font-weight:400;letter-spacing:-.022em;color:var(--sf-navy)}
  .hero-copy-columns{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:2.125rem}
  .hero-copy-columns > p + p{border-left:1px solid var(--border-color);padding-left:2.125rem}
  .hero-ed .hero-goal{margin-top:1.5625rem;padding-top:1.1875rem;border-top:1px solid var(--border-color);line-height:1.65;color:var(--sf-navy)}
  .hero-ed .hero-question strong,.hero-ed .hero-goal strong{color:var(--sf-blue)}
  .hero-ed .stat-strip{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:.75rem;margin-top:1.75rem;padding-top:1.375rem;border-top:1px solid var(--border-color)}
  .hero-ed .stat-strip div{min-width:0}
  .hero-ed .stat-strip b{display:block;font-family:var(--font-display);font-size:1.75rem;font-weight:600;line-height:1.15;letter-spacing:-.04em;color:var(--sf-blue);font-variant-numeric:tabular-nums}
  .hero-ed .stat-strip span{display:block;font-size:.75rem;line-height:1.5;margin-top:.4375rem;color:var(--text-secondary)}
  @media(max-width:740px){
    .hero-ed-inner{padding:1.75rem 1.5rem 1.5rem}
    .hero-ed h1{font-size:2.1875rem}
    .hero-mascots{width:160px;flex-basis:160px}
    .hero-ed .hero-question{font-size:1.375rem}
    .hero-copy-columns{gap:1.4375rem}
    .hero-copy-columns > p + p{padding-left:1.4375rem}
  }
  @media(max-width:500px){
    .hero-ed-inner{padding:1.5625rem 1.3125rem 1.5rem}
    .hero-ed h1{font-size:2rem}
    .hero-title-row{gap:.625rem;align-items:flex-start;flex-direction:column;padding-bottom:1.25rem}
    .hero-mascots{flex-basis:auto;align-self:flex-end;margin-top:-.25rem}
    .hero-ed .hero-question{font-size:1.3125rem;margin:1.3125rem 0}
    .hero-copy-columns{grid-template-columns:minmax(0,1fr);gap:1rem}
    .hero-copy-columns > p + p{border-left:0;padding-left:0}
    .hero-ed .stat-strip{grid-template-columns:repeat(3,minmax(0,1fr));row-gap:1.25rem}
  }

  /* section nav (sticky under the family nav) */
  .section-nav{position:sticky;top:var(--nav-h);z-index:19;background:rgba(255,255,255,.96);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--border-color)}
  .section-nav-inner{display:flex;align-items:center;min-height:60px;max-width:1120px;margin:0 auto;padding:0 2rem;gap:.4rem}
  .section-nav-title{display:flex;align-items:center;flex:0 0 auto;margin-right:.4rem;padding-right:1.2rem;border-right:1px solid var(--border-color);font-size:.68rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--sf-navy)}
  .section-nav-track{display:flex;align-items:center;flex:1 1 auto;min-width:0;gap:clamp(1.5rem,3.5vw,2.75rem);overflow-x:auto;scrollbar-width:none;scroll-snap-type:x proximity}
  .section-nav-track::-webkit-scrollbar{display:none}
  .section-nav a.sn-link{position:relative;display:flex;align-items:center;gap:.55rem;flex:0 0 auto;min-height:60px;padding:.75rem .125rem;color:var(--sf-navy);font-size:1rem;font-weight:600;line-height:1.4;text-decoration:none;white-space:nowrap;scroll-snap-align:start;transition:color .18s ease}
  .sn-icon{width:18px;height:18px;flex:none;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round;opacity:.7}
  .sn-link:hover .sn-icon,.sn-link[aria-current=location] .sn-icon{opacity:1}
  .section-nav a.sn-link::after{content:'';position:absolute;left:.125rem;right:.125rem;bottom:0;height:3px;border-radius:3px 3px 0 0;background:var(--sf-blue);transform:scaleX(0);transform-origin:left;transition:transform .2s ease,opacity .2s ease;opacity:0}
  .section-nav a.sn-link:hover,.section-nav a.sn-link[aria-current=location]{color:var(--sf-blue-deep)}
  .section-nav a.sn-link:hover::after{transform:scaleX(1);opacity:.3}
  .section-nav a.sn-link[aria-current=location]::after{transform:scaleX(1);opacity:1}
  @media(max-width:640px){
    body.has-section-nav .site-nav{position:static}
    .section-nav{top:0}
    .section-nav-title{display:none}
    .section-nav-inner{padding:0 1rem;position:relative;min-height:54px}
    .section-nav a.sn-link{min-height:54px;font-size:.9375rem}
    .section-nav-track{gap:1.5rem}
  }

  /* editorial sections: big heading left, lead or prose right */
  .ed,.board-section{padding:4.2rem 0;border-top:1px solid var(--border-color);scroll-margin-top:calc(var(--nav-h) + var(--subnav-h))}
  .ed-grid{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);gap:1.6rem 4rem;align-items:start}
  .ed-head .kicker{display:block;margin-bottom:.9rem}
  .ed-head h2{font-family:var(--font-display);font-size:clamp(1.9rem,3.6vw,2.6rem);font-weight:700;color:var(--sf-navy);line-height:1.15;letter-spacing:-.01em;margin:0}
  .ed-lead{font-family:var(--font-display);font-size:1.1rem;line-height:1.65;color:var(--text-secondary);padding-top:2.3rem;margin:0}
  .ed-prose p{font-size:1.02rem;line-height:1.8;color:var(--text-secondary);margin:0 0 1rem}
  .ed-prose strong{color:var(--text-primary)}
  @media(max-width:760px){.ed-grid{grid-template-columns:1fr;gap:1.1rem}.ed-lead{padding-top:0}}

  /* two research directions, presented as equal-width cards */
  .q-row{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1.5rem;align-items:stretch;margin-top:2.4rem}
  .q-card{background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:16px;padding:1.5rem 1.5rem 1.3rem;display:flex;flex-direction:column;box-shadow:var(--shadow-sm);transition:transform .25s ease,box-shadow .25s ease,border-color .25s ease}
  .q-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-md);border-color:rgba(1,118,211,.4)}
  .q-label{font-size:.68rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--sf-blue-deep);margin-bottom:.9rem}
  .q-title{font-family:var(--font-display);font-size:1.25rem;font-weight:700;color:var(--sf-navy);line-height:1.3;margin:0 0 .8rem}
  .q-meta{display:flex;justify-content:space-between;align-items:baseline;gap:.6rem;flex-wrap:wrap;font-size:.74rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--sf-navy);padding-bottom:.7rem;border-bottom:1px solid var(--border-color);margin-bottom:.8rem}
  .q-meta a{color:var(--sf-blue-deep);text-decoration:none;letter-spacing:0;text-transform:none;font-size:.82rem;white-space:nowrap}
  .q-meta a:hover{text-decoration:underline}
  .q-meta .soft{color:var(--text-muted);letter-spacing:0;text-transform:none;font-weight:600;font-size:.8rem}
  .q-card p{font-size:1rem;line-height:1.65;color:var(--text-secondary);margin:0 0 1rem;flex:1}
  .q-test{border-top:1px solid var(--border-color);padding-top:.7rem;font-size:.82rem;line-height:1.5;color:var(--text-primary);font-weight:600}
  .q-test small{display:block;font-size:.64rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--text-muted);margin-bottom:.15rem}
  @media(max-width:900px){.q-row{grid-template-columns:1fr}}

  /* dark stepper card */
  .stepper{background:var(--sf-navy);color:#fff;border-radius:16px;padding:1.4rem 1.6rem 1.1rem;box-shadow:var(--shadow-lg)}
  .step{display:grid;grid-template-columns:32px 1fr;gap:.9rem;align-items:center;padding:.75rem 0;border-bottom:1px solid rgba(255,255,255,.14)}
  .step:last-of-type{border-bottom:0}
  .step i,.stepper-foot i{flex:none;width:30px;height:30px;border-radius:50%;border:1px solid rgba(255,255,255,.4);display:flex;align-items:center;justify-content:center;font-style:normal;font-size:.68rem;font-weight:700;letter-spacing:.04em;color:#dbeafe}
  .step small{display:block;font-size:.62rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:#93c5fd;margin-bottom:.1rem}
  .step b{font-size:.95rem;font-weight:600;color:#fff}
  .step .desc{display:block;font-size:.8rem;color:rgba(255,255,255,.72);margin-top:.15rem;line-height:1.45}
  .stepper-foot{display:flex;align-items:center;gap:.8rem;margin-top:.8rem;padding-top:.9rem;border-top:1px solid rgba(255,255,255,.22);font-size:.82rem;line-height:1.5;color:rgba(255,255,255,.85)}
  .stepper-foot i{font-size:1rem;color:#fff}
  .stepper .step{opacity:0;transform:translateY(8px)}
  .stepper.is-visible .step{animation:reveal-cell .45s ease forwards;animation-delay:calc(var(--i,0)*110ms)}
  html.no-js .stepper .step{opacity:1;transform:none}

  /* drawn loop line */
  .loop-line{width:100%;max-width:440px;height:auto;display:block;margin-top:1.7rem;overflow:visible}
  .loop-line path{fill:none;stroke:var(--sf-blue);stroke-width:2;stroke-linecap:round;stroke-dasharray:1;stroke-dashoffset:1}
  .loop-line .ll-back{stroke:var(--sf-orange)}
  .is-visible .loop-line .ll-main{animation:draw-trend 1s ease forwards}
  .is-visible .loop-line .ll-back{animation:draw-trend .9s ease .9s forwards}
  .loop-line circle{fill:#fff;stroke:var(--sf-blue);stroke-width:2;opacity:0}
  .is-visible .loop-line circle{animation:reveal-dot .3s ease forwards;animation-delay:calc(var(--i,0)*.18s)}
  .loop-line text{font-family:var(--font-body);font-size:11px;font-weight:600;fill:var(--text-secondary)}
  .loop-line .ll-note{fill:var(--sf-orange-text);font-weight:500}
  html.no-js .loop-line path{stroke-dashoffset:0}
  html.no-js .loop-line circle{opacity:1}

  /* sub-project switcher */
  .board-hint{font-size:.8rem;color:var(--text-muted);text-align:right;margin-top:.7rem}
  .board{display:grid;grid-template-columns:250px minmax(0,1fr);border:1px solid var(--border-color);border-radius:16px;background:var(--bg-secondary);overflow:hidden;box-shadow:var(--shadow-md);margin-top:2rem}
  .board-tabs{display:flex;flex-direction:column;border-right:1px solid var(--border-color);background:var(--bg-tertiary)}
  .board-tab{font:inherit;text-align:left;background:none;border:0;border-left:3px solid transparent;border-bottom:1px solid var(--border-color);padding:1.3rem 1.2rem;cursor:pointer;color:var(--text-secondary);flex:1;transition:background .2s ease,border-color .2s ease}
  .board-tab:last-child{border-bottom:0}
  .board-tab small{display:block;font-size:.66rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--sf-blue-deep);margin-bottom:.4rem}
  .board-tab b{display:block;font-family:var(--font-display);font-size:1.12rem;font-weight:700;color:var(--sf-navy);line-height:1.25}
  .board-tab span{display:block;font-size:.8rem;margin-top:.25rem}
  .board-tab:hover,.board-tab:focus-visible,.board-tab[aria-selected=true]{background:var(--bg-secondary);border-left-color:var(--board-accent);outline:0}
  .board-stage{min-width:0;position:relative}
  .board-panel{padding:1.6rem 1.8rem 1.5rem}
  html:not(.no-js) .board-panel:not(.active){display:none}
  .board-panel.active{animation:panel-in .3s ease}
  .panel-head{display:flex;justify-content:space-between;align-items:flex-start;gap:1.2rem;flex-wrap:wrap;padding-bottom:1rem;border-bottom:1px solid var(--border-color);margin-bottom:1.2rem}
  .panel-head small{display:block;font-size:.72rem;color:var(--text-muted);margin-bottom:.2rem}
  .panel-head h3{font-family:var(--font-display);font-size:1.5rem;font-weight:700;color:var(--sf-navy);margin:0;line-height:1.2}
  .panel-head>div:first-child{flex:1 1 260px;min-width:0}
  .headline-stat{text-align:right;flex:0 1 auto;max-width:300px}
  .headline-stat b{display:block;font-family:var(--font-display);font-size:1.5rem;font-weight:700;color:var(--board-accent);line-height:1.15}
  .headline-stat span{font-size:.76rem;color:var(--text-muted)}
  .viz-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:1rem}
  .viz-card{border:1px solid var(--border-color);border-radius:12px;padding:1.1rem 1.2rem;background:var(--bg-primary)}
  .viz-card h4{font-size:.9rem;font-weight:700;color:var(--text-primary);margin:0 0 .15rem}
  .viz-card .sub{font-size:.74rem;color:var(--text-muted);margin-bottom:.9rem}
  .gain-row{display:grid;grid-template-columns:minmax(90px,150px) 1fr 54px;align-items:center;gap:.7rem;font-size:.78rem;line-height:1.3;color:var(--text-secondary);margin:.5rem 0}
  .gain-track{height:14px;border-radius:4px;background:#e7edf3;overflow:hidden}
  .gain-fill{height:100%;border-radius:4px;background:var(--board-accent);transform-origin:left center;transform:scaleX(0)}
  .board-panel.active .gain-fill{animation:grow-bar .8s cubic-bezier(.4,0,.2,1) forwards;animation-delay:calc(var(--i,0)*90ms)}
  .gain-row b{font-family:var(--font-display);font-size:.95rem;color:var(--text-primary);text-align:right;white-space:nowrap}
  .big-stats{display:grid;gap:.9rem}
  .big-stat b{display:block;font-family:var(--font-display);font-size:2.1rem;font-weight:700;line-height:1.1;background:var(--gradient-deep);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;color:transparent}
  .big-stat span{display:block;font-size:.8rem;color:var(--text-secondary);line-height:1.45}
  .fact-list{list-style:none;margin:0;padding:0}
  .fact-list li{display:block;padding:.55rem 0;border-top:1px solid var(--border-color);font-size:.8rem;color:var(--text-secondary);line-height:1.45}
  .fact-list li:first-child{border-top:0;padding-top:.1rem}
  .fact-list li:last-child{padding-bottom:.1rem}
  .fact-list b{display:block;font-family:var(--font-display);color:var(--text-primary);font-size:.95rem;margin-bottom:.1rem}
  .panel-note{font-size:.8rem;color:var(--text-muted);margin:1rem 0 0;line-height:1.55}
  .panel-note strong{color:var(--text-secondary)}
  .panel-actions{display:flex;gap:.7rem;flex-wrap:wrap;margin-top:1.1rem;padding-top:1.1rem;border-top:1px solid var(--border-color)}
  .panel-actions .btn{padding:.6rem 1.1rem;font-size:.86rem}
  html.no-js .gain-fill{transform:none}
  @media(max-width:820px){
    .board{grid-template-columns:1fr}
    .board-tabs{flex-direction:row;border-right:0;border-bottom:1px solid var(--border-color)}
    .board-tab{border-left:0;border-bottom:3px solid transparent;padding:1rem}
    .board-tab:last-child{border-bottom:3px solid transparent}
    .board-tab:hover,.board-tab:focus-visible,.board-tab[aria-selected=true]{border-bottom-color:var(--board-accent)}
    .viz-grid{grid-template-columns:1fr}
    .board-panel{padding:1.2rem 1.1rem}
    .headline-stat{text-align:left}
  }

  /* definition rows and footer */
  .def-rows{margin-top:1.2rem;border-top:1px solid var(--border-color)}
  .def-row{display:grid;grid-template-columns:200px 1fr;gap:1rem;padding:1rem 0;border-bottom:1px solid var(--border-color)}
  .def-row b{font-size:.9rem;color:var(--sf-blue-deep)}
  .def-row p{font-size:.92rem;color:var(--text-secondary);line-height:1.6;margin:0}
  .def-row a{font-weight:600;text-decoration:none}
  .def-row a:hover{text-decoration:underline}
  @media(max-width:640px){.def-row{grid-template-columns:1fr;gap:.3rem}}
  .foot-ed{display:flex;justify-content:space-between;gap:.6rem 1rem;flex-wrap:wrap;padding:1.6rem 2rem;border-top:1px solid var(--border-color);font-size:.8rem;color:var(--text-muted);background:var(--bg-tertiary)}
  .foot-ed a{color:var(--text-secondary);text-decoration:none;font-weight:600}
  .foot-ed a:hover{color:var(--sf-blue-deep)}
  .foot-ed .fine{flex-basis:100%;font-size:.76rem;line-height:1.5}

  /* scroll reveal and keyframes */
  .reveal{opacity:0;transform:translateY(14px);transition:opacity .6s ease,transform .6s ease;transition-delay:calc(var(--i,0)*80ms)}
  .reveal.is-visible{opacity:1;transform:none}
  html.no-js .reveal{opacity:1;transform:none}
  @keyframes grow-bar{to{transform:scaleX(1)}}
  @keyframes draw-trend{to{stroke-dashoffset:0}}
  @keyframes reveal-cell{to{opacity:1;transform:translateY(0)}}
  @keyframes reveal-dot{to{opacity:1}}
  @keyframes panel-in{from{opacity:0;transform:translateY(7px)}to{opacity:1;transform:none}}
  @media(prefers-reduced-motion:reduce){
    .reveal,.reveal.is-visible{transition:none;opacity:1;transform:none}
    .stepper .step,.stepper.is-visible .step{opacity:1;transform:none;animation:none}
    .gain-fill,.board-panel.active .gain-fill{transform:none;animation:none}
    .loop-line path,.is-visible .loop-line path{stroke-dashoffset:0;animation:none}
    .loop-line circle,.is-visible .loop-line circle{opacity:1;animation:none}
    .board-panel.active{animation:none}
    .q-card,.board-tab,.section-nav a.sn-link,.section-nav a.sn-link::after{transition:none}
  }

  /* Shared article details, accessibility, and responsive behavior. */
  body{-webkit-font-smoothing:antialiased}
  .bg-pattern{background-image:radial-gradient(ellipse at 50% 0%,rgba(27,150,255,.085),transparent 55%)}
  .project-family{display:block;margin-bottom:.55rem;font-size:1.1rem;font-weight:600;letter-spacing:.01em;color:var(--sf-blue-deep)}
  .hero-actions{display:flex;flex-wrap:wrap;justify-content:center;gap:.75rem;margin:0 0 1.8rem}
  .hero .authors{margin-top:.3rem}
  .hero .affiliation{font-size:.875rem}
  .article-hero .hero-description{max-width:760px}
  .section-nav-track{position:relative}
  .section-nav-title{font-size:.75rem}
  .q-meta{overflow-wrap:anywhere}
  .q-test small,.q-label,.step small,.board-tab small{font-size:.75rem}
  .q-test,.q-meta a,.q-meta .soft,.step .desc,.fact-list li,.board-tab span,.panel-note,.def-row b{font-size:.875rem}
  .board-tab{min-width:0;overflow-wrap:anywhere}
  .panel-head h3{overflow-wrap:anywhere}
  .team{background:rgba(234,245,254,.5)}
  .foot-ed{padding:2rem max(2rem,calc((100vw - 1056px)/2));align-items:center;text-align:left;gap:1rem;background:var(--bg-secondary);font-size:.875rem}
  .footer-brand{display:flex;align-items:center;gap:.75rem;color:var(--sf-navy)}
  .footer-brand img{height:32px;width:auto;margin:0}
  .footer-brand strong,.footer-brand small{display:block;line-height:1.6}
  .footer-brand small{font-size:.8rem;color:var(--text-secondary)}
  .footer-links{display:flex;flex-wrap:wrap;gap:1.25rem}
  .foot-ed .fine{font-size:.8rem;padding-top:.75rem;border-top:1px solid var(--border-color)}
  .skip-link{position:fixed;top:.75rem;left:.75rem;z-index:100;transform:translateY(-200%);padding:.65rem 1rem;border-radius:8px;background:var(--sf-navy);color:#fff;font-weight:600;text-decoration:none}
  .skip-link:focus{transform:none}
  :is(a,button,summary,video,[tabindex]):focus-visible{outline:3px solid var(--sf-blue);outline-offset:4px}
  .section-nav a.sn-link:focus-visible,.board-tab:focus-visible{outline:2px solid var(--sf-blue);outline-offset:-2px}
  section[id],header[id],main[id]{scroll-margin-top:calc(var(--nav-h) + var(--subnav-h) + 20px)}
  #main-content:focus{outline:none}
  @media(max-width:640px){
    .container{padding:0 1.25rem}
    .hero{padding:2.75rem 1.25rem 2.25rem}
    .hero .authors,.team .authors{gap:1.25rem;display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}
    .ed,.board-section{padding:2.75rem 0}
    .foot-ed{padding:1.75rem 1.25rem}
    .board-hint{font-size:.8rem;text-align:left}
    .board-tabs{align-items:stretch}
    .board-tab{flex:1}
    .hero-actions .btn{justify-content:center;text-align:center}
  }
  @media(prefers-reduced-motion:reduce){
    html{scroll-behavior:auto}
    *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
  }