:root{
    --ink:#0a1733; --ink-2:#18254a; --ink-soft:#4a5878; --muted:#8b96b3;
    --line:#e4e8f0; --line-soft:#eef1f7; --bg:#ffffff; --bg-tint:#f6f8fd; --bg-deep:#0a1733;
    --blue:#1e4ed8; --blue-soft:#e8eefd; --amber:#d97706; --amber-soft:#fef3e2; --green:#0d8a5b; --coral:#dc2626;
    --display:'Inter Tight',system-ui,sans-serif; --body:'Inter',system-ui,sans-serif;
    --serif:'Instrument Serif',Georgia,serif; --mono:'JetBrains Mono',ui-monospace,monospace;
    --maxw:1200px; --shadow:0 1px 2px rgba(10,23,51,.05), 0 22px 50px -30px rgba(10,23,51,.26);
  }
  *{box-sizing:border-box}
  html{scroll-behavior:smooth}
  @media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
  body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--body);font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
  ::selection{background:var(--blue-soft);color:var(--ink)}
  a{color:inherit;text-decoration:none}
  img,svg{display:block;max-width:100%}
  .wrap{max-width:var(--maxw);margin:0 auto;padding:0 28px}
  .mono{font-family:var(--mono);font-size:11.5px;letter-spacing:.16em;text-transform:uppercase}
  .serif-em{font-family:var(--serif);font-style:italic;font-weight:400;color:var(--blue);letter-spacing:-.015em}

  #scrollbar{position:fixed;top:0;left:0;height:3px;width:0;background:var(--blue);z-index:120;transition:width .08s linear}

  /* ---- real site nav ---- */
  .topnav{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.85);backdrop-filter:blur(14px) saturate(180%);-webkit-backdrop-filter:blur(14px) saturate(180%);border-bottom:1px solid var(--line-soft)}
  .nav-row{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:14px 0}
  .brand{display:inline-flex;align-items:center;gap:9px;font-family:var(--display);font-weight:700;font-size:21px;color:var(--ink);letter-spacing:-.02em;line-height:1}
  .brand-mark{width:30px;height:26px;flex-shrink:0}
  .nav-center{display:none;gap:36px;font-size:16px;color:var(--ink-soft)}
  .nav-center a{font-weight:500}
  .nav-center a:hover,.nav-center a.is-active{color:var(--ink)}
  .nav-right{display:flex;align-items:center;flex-shrink:0}
  .btn{display:inline-flex;align-items:center;gap:8px;padding:11px 20px;border-radius:6px;font-family:var(--display);font-size:14px;font-weight:600;border:1px solid transparent;transition:all .18s ease;cursor:pointer}
  .btn .arrow{transition:transform .2s}
  .btn:hover .arrow{transform:translateX(2px)}
  .btn-primary{background:#14306b;color:#fff}
  .btn-primary:hover{background:#102a5c;transform:translateY(-1px);box-shadow:0 8px 20px -8px rgba(10,23,51,.5)}
  .btn-ghost{background:transparent;color:var(--ink);border-color:var(--line)}
  .btn-ghost:hover{background:var(--bg-tint);border-color:var(--ink-soft)}
  @media(max-width:880px){.nav-center{display:none}.nav-right .btn{padding:9px 14px;font-size:13px}}
  @media(min-width:1024px){.nav-center{display:flex}}

  /* ---- hero (light) ---- */
  .hero{position:relative;background:var(--bg);overflow:hidden;border-bottom:1px solid var(--line-soft)}
  .hero-grid{position:absolute;inset:0;pointer-events:none;background-image:linear-gradient(to right,var(--line-soft) 1px,transparent 1px),linear-gradient(to bottom,var(--line-soft) 1px,transparent 1px);background-size:64px 64px;opacity:.5;-webkit-mask-image:radial-gradient(ellipse 75% 70% at 50% 25%,#000 25%,transparent 75%);mask-image:radial-gradient(ellipse 75% 70% at 50% 25%,#000 25%,transparent 75%)}
  .hero-glow{position:absolute;top:-30%;left:50%;transform:translateX(-50%);width:1100px;height:560px;background:radial-gradient(ellipse 50% 60% at 50% 45%,rgba(30,78,216,.07),transparent 70%);pointer-events:none}
  .hero .wrap{position:relative;padding:64px 28px 56px}
  .kicker{display:inline-flex;align-items:center;gap:12px;margin-bottom:24px}
  .kicker .rule{width:26px;height:1px;background:var(--amber);opacity:.6}
  .kicker .mono{color:var(--ink-soft)}
  .hero h1{font-family:var(--display);font-weight:800;font-size:clamp(36px,6vw,68px);line-height:1.02;letter-spacing:-.03em;margin:0 0 20px;max-width:16ch}
  .hero .lede{font-size:clamp(17px,2vw,20px);color:var(--ink-soft);max-width:60ch;margin:0 0 30px;line-height:1.55}
  .hero-cta{display:flex;flex-wrap:wrap;gap:12px;align-items:center}
  .btn .ico{display:inline-flex;align-items:center;line-height:0}
  .btn .ico svg{display:block}
  .hero-meta{display:flex;flex-wrap:wrap;gap:34px;margin-top:46px;padding-top:28px;border-top:1px solid var(--line)}
  .hero-meta .n{font-family:var(--display);font-size:26px;font-weight:700;line-height:1;letter-spacing:-.02em}
  .hero-meta .l{color:var(--muted);font-size:12px;margin-top:6px;letter-spacing:.02em}

  /* ---- layout ---- */
  .course{display:grid;grid-template-columns:240px 1fr;gap:56px;max-width:var(--maxw);margin:0 auto;padding:56px 28px 40px;align-items:start}
  @media(max-width:920px){.course{grid-template-columns:1fr;gap:0;padding-top:36px}}
  .toc{position:sticky;top:92px}
  @media(max-width:920px){.toc{display:none}}
  .toc .mono{color:var(--muted);display:block;margin-bottom:16px}
  .toc ol{list-style:none;margin:0;padding:0;counter-reset:m}
  .toc li{counter-increment:m}
  .toc a{display:flex;gap:11px;align-items:baseline;color:var(--muted);padding:9px 0;font-size:14px;line-height:1.35;border-top:1px solid var(--line-soft);transition:.15s}
  .toc a:before{content:counter(m,decimal-leading-zero);font-family:var(--mono);font-size:11px;color:var(--amber)}
  .toc a:hover{color:var(--ink)}
  .toc a.active{color:var(--ink);font-weight:600}
  .toc .prog{margin-top:20px;padding-top:16px;border-top:1px solid var(--line)}
  .toc .prog .pct{display:flex;justify-content:space-between;font-family:var(--mono);font-size:11.5px;color:var(--muted)}
  .toc .prog .barwrap{height:6px;border-radius:99px;background:var(--bg-tint);overflow:hidden;margin-top:8px;border:1px solid var(--line-soft)}
  .toc .prog .bar{height:100%;width:0;background:var(--blue);border-radius:99px;transition:width .5s cubic-bezier(.22,1,.36,1)}
  .toc a.done:after{content:"✓";margin-left:auto;color:var(--green);font-size:12px}

  .lead-block{max-width:64ch;margin-bottom:8px}
  .lead-block p{font-size:19px;line-height:1.6;color:var(--ink-2)}
  .lead-block .drop:first-letter{font-family:var(--serif);font-weight:400;font-size:3.6em;float:left;line-height:.74;padding:8px 12px 0 0;color:var(--blue)}

  .module{scroll-margin-top:88px;padding:38px 0;border-top:1px solid var(--line)}
  .module:first-of-type{border-top:none}
  .m-head{display:flex;align-items:flex-start;gap:16px}
  .m-num{font-family:var(--mono);font-size:12px;color:var(--amber);border:1px solid var(--line);border-radius:7px;padding:6px 9px;margin-top:6px;white-space:nowrap}
  .m-head h2{font-family:var(--display);font-weight:700;font-size:clamp(24px,3.4vw,34px);line-height:1.1;letter-spacing:-.02em;margin:0}
  .m-tools{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin:16px 0 24px}
  .chip{display:inline-flex;align-items:center;gap:7px;font-family:var(--mono);font-size:11px;letter-spacing:.06em;color:var(--ink-soft);background:var(--bg-tint);border:1px solid var(--line);border-radius:999px;padding:6px 12px}
  .listen{cursor:pointer;border:1px solid var(--blue);color:var(--blue);background:transparent;transition:.18s;text-transform:uppercase}
  .listen:hover,.listen.playing{background:var(--blue);color:#fff}
  .listen .ico{line-height:0}.listen .ico svg{display:block}
  .body{font-size:17px;max-width:66ch}
  .body p{margin:0 0 18px;color:var(--ink-2)}
  .body strong{font-weight:600;color:var(--ink)}
  .body code{font-family:var(--mono);font-size:.85em;background:var(--bg-tint);padding:2px 6px;border-radius:5px;border:1px solid var(--line-soft);color:var(--ink)}

  /* ---- light callouts ---- */
  .lead-answer{background:var(--bg-tint);border:1px solid var(--line);border-left:3px solid var(--blue);border-radius:10px;padding:18px 20px;margin:0 0 22px;max-width:66ch}
  .lead-answer p{margin:0;font-size:16.5px;color:var(--ink);line-height:1.55}
  .callout{background:var(--amber-soft);border:1px solid #f3d9a8;border-radius:10px;padding:18px 20px;margin:24px 0;max-width:66ch}
  .callout .clabel{font-family:var(--mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:#a8480a;margin-bottom:8px}
  .callout p{margin:0;font-size:15.5px;color:var(--ink-2)}
  .takeaways{background:var(--bg-tint);border:1px solid var(--line);border-radius:12px;padding:22px 24px;margin:28px 0;max-width:66ch}
  .takeaways .mono{color:var(--blue);display:block;margin-bottom:12px}
  .takeaways ul{margin:0;padding:0;list-style:none}
  .takeaways li{position:relative;padding:9px 0 9px 24px;border-top:1px solid var(--line);font-size:15.5px;line-height:1.5;color:var(--ink-2)}
  .takeaways li:first-child{border-top:none}
  .takeaways li:before{content:"";position:absolute;left:2px;top:17px;width:7px;height:7px;border-radius:50%;background:var(--amber)}
  .takeaways li b{color:var(--ink);font-weight:600}

  .m-foot{margin-top:26px;max-width:66ch}
  .mark{display:inline-flex;align-items:center;gap:10px;cursor:pointer;border:1px solid var(--line);background:var(--bg);color:var(--ink);border-radius:8px;padding:10px 18px;font-family:var(--display);font-weight:600;font-size:14px;transition:.18s}
  .mark:hover{border-color:var(--ink-soft);background:var(--bg-tint)}
  .mark.done{background:var(--green);border-color:var(--green);color:#fff}
  .mark .box{width:17px;height:17px;border:2px solid currentColor;border-radius:5px;display:grid;place-items:center;font-size:11px}
  .mark.done .box{background:#fff;color:var(--green)}

  /* ---- figures ---- */
  .fig{margin:28px 0;max-width:780px}
  .fig-cap{font-family:var(--mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin-bottom:11px;display:flex;align-items:center;gap:10px}
  .fig-cap:before{content:"";width:18px;height:1px;background:var(--amber);flex-shrink:0}
  .panel{background:var(--bg);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);overflow:hidden}
  .panel-pad{padding:clamp(18px,3vw,28px)}
  .replay{margin-left:auto;display:inline-flex;align-items:center;gap:7px;cursor:pointer;font-family:var(--mono);font-size:10.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--blue);background:transparent;border:1px solid var(--line);border-radius:999px;padding:6px 12px;transition:.18s}
  .replay:hover{background:var(--blue);color:#fff;border-color:var(--blue)}

  /* Fig 1 simulator (light) */
  .sim-bar{display:flex;align-items:center;gap:14px;padding:15px 20px;border-bottom:1px solid var(--line);background:var(--bg-tint)}
  .sim-bar .mono{color:var(--ink-soft)}
  .switch{margin-left:auto;width:50px;height:27px;border-radius:99px;border:none;background:var(--green);position:relative;cursor:pointer;transition:.25s;flex-shrink:0}
  .switch.off{background:#c2c9d6}
  .switch .knob{position:absolute;top:3px;left:3px;width:21px;height:21px;border-radius:50%;background:#fff;transition:.25s cubic-bezier(.22,1,.36,1);box-shadow:0 1px 3px rgba(0,0,0,.2)}
  .switch.off .knob{left:26px}
  .sim-state{font-weight:600;font-size:14px;min-width:52px}
  .sim-chat{padding:20px}
  .ask{background:var(--bg-tint);border:1px solid var(--line-soft);border-radius:10px;padding:13px 15px;margin-bottom:12px;font-size:15px;color:var(--ink-2)}
  .ask .mono{display:block;color:var(--muted);font-size:10px;margin-bottom:5px}
  .ai{background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:15px 16px}
  .ai .mono{display:block;color:var(--blue);font-size:10px;margin-bottom:8px}
  .ai p{margin:0 0 10px;font-size:15px;line-height:1.5;color:var(--ink-2)}
  .ai b{color:var(--ink);font-weight:600}
  .mini{font-family:var(--mono);font-size:12px;background:var(--bg-deep);color:#cdd9f5;border-radius:8px;padding:11px 13px;margin:0 0 10px;white-space:pre-wrap;line-height:1.5}
  .cite{font-size:12.5px;color:var(--ink-soft);display:flex;align-items:center;gap:7px}
  .cite a{color:var(--blue);border-bottom:1px dotted rgba(30,78,216,.5)}
  .cite.muted{color:var(--muted)}

  /* Fig 2 fan-out (light) */
  .fan svg{width:100%;height:auto;display:block}
  .fan .node rect{fill:var(--bg);stroke:var(--line);stroke-width:1}
  .fan .node.q rect{fill:var(--ink);stroke:var(--ink)}
  .fan .node.q text{fill:#fff}
  .fan .node.ans rect{fill:var(--blue);stroke:var(--blue)}
  .fan .node.ans text{fill:#fff}
  .fan .node.pass rect{fill:var(--bg-tint);stroke:var(--blue);stroke-dasharray:3 3}
  .fan .node text{fill:var(--ink-soft);font-family:var(--mono);font-size:12px}
  .fan .node .t{font-family:var(--body);font-size:13px;font-weight:500;fill:var(--ink)}
  .fan .node.q .t{fill:#fff}
  .fan .lnk{fill:none;stroke:var(--blue);stroke-width:1.5;opacity:.5}
  .fan .stage{opacity:0;transform:translateY(10px);transition:opacity .5s ease,transform .5s cubic-bezier(.22,1,.36,1)}
  .fan.run .stage{opacity:1;transform:none}
  .fan.run .s1{transition-delay:.05s}.fan.run .s2{transition-delay:.5s}.fan.run .s3{transition-delay:.95s}.fan.run .s4{transition-delay:1.4s}
  .fan .lnk{stroke-dasharray:1;stroke-dashoffset:1;transition:stroke-dashoffset .5s ease}
  .fan.run .l1{transition-delay:.35s;stroke-dashoffset:0}.fan.run .l2{transition-delay:.8s;stroke-dashoffset:0}.fan.run .l3{transition-delay:1.25s;stroke-dashoffset:0}
  @media(prefers-reduced-motion:reduce){.fan .stage{opacity:1;transform:none}.fan .lnk{stroke-dashoffset:0}}

  /* Fig 3 patterns */
  .pat-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
  @media(max-width:620px){.pat-grid{grid-template-columns:1fr}}
  .pat{text-align:left;background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:20px;cursor:pointer;transition:.18s;font-family:inherit}
  .pat:hover,.pat.open{border-color:var(--blue);box-shadow:var(--shadow)}
  .pat .ic{width:38px;height:38px;border-radius:9px;background:var(--blue-soft);color:var(--blue);display:grid;place-items:center;margin-bottom:13px}
  .pat h4{margin:0 0 6px;font-family:var(--display);font-size:16.5px;font-weight:600;letter-spacing:-.01em;color:var(--ink)}
  .pat .d{margin:0;font-size:14px;color:var(--ink-soft);line-height:1.5}
  .pat .ex{max-height:0;overflow:hidden;opacity:0;transition:max-height .3s ease,opacity .3s ease,margin .3s ease}
  .pat.open .ex{max-height:200px;opacity:1;margin-top:13px}
  .pat .ex p{margin:0;font-size:13.5px;color:var(--ink-2);background:var(--bg-tint);border-left:2px solid var(--blue);padding:10px 12px;line-height:1.5}
  .pat .ex code{font-family:var(--mono);font-size:.9em}

  /* Fig 4 machine-readable layer */
  .mrl{display:grid;grid-template-columns:150px 1fr;gap:24px;align-items:center}
  @media(max-width:620px){.mrl{grid-template-columns:1fr}}
  .mrl .src{text-align:center}
  .mrl .pg{width:80px;height:100px;margin:0 auto 10px;border-radius:9px;background:var(--bg);border:1px solid var(--line);position:relative;box-shadow:var(--shadow)}
  .mrl .pg:before{content:"";position:absolute;left:13px;right:13px;top:16px;height:6px;border-radius:3px;background:var(--blue);opacity:.8;box-shadow:0 15px 0 var(--line-soft),0 28px 0 var(--line-soft),0 41px 0 var(--line-soft)}
  .mrl .src .lbl{font-size:13px;color:var(--ink-soft)}
  .mrl .outs{display:grid;gap:10px}
  .mrl .row{display:flex;align-items:center;gap:13px;background:var(--bg-tint);border:1px solid var(--line);border-radius:10px;padding:12px 15px}
  .mrl .tag{font-family:var(--mono);font-size:11px;font-weight:600;padding:5px 9px;border-radius:6px;white-space:nowrap}
  .mrl .row.h .tag{background:var(--line-soft);color:var(--ink-soft)}
  .mrl .row.m .tag{background:var(--blue-soft);color:var(--blue)}
  .mrl .row.l .tag{background:var(--ink);color:#fff}
  .mrl .tx{font-size:14px;color:var(--ink-2)}
  .mrl .tx b{color:var(--ink);font-weight:600}
  .code{margin-top:18px;background:var(--bg-deep);border-radius:10px;padding:15px 17px;overflow-x:auto}
  .code .cbar{display:flex;align-items:center;gap:7px;margin-bottom:10px}
  .code .cbar i{width:10px;height:10px;border-radius:50%;background:#33415e;display:block}
  .code .cbar span{margin-left:8px;font-family:var(--mono);font-size:11px;color:#7e8aa6;letter-spacing:.05em}
  .code pre{margin:0;font-family:var(--mono);font-size:12.5px;line-height:1.7;color:#cdd9f5;white-space:pre}
  .code .k{color:#7fa0ff}.code .u{color:#9ec1ff}.code .c{color:#7e8aa6}

  /* Fig 5 matrix */
  .mx-y{display:flex}
  .mx-y .yl{writing-mode:vertical-rl;transform:rotate(180deg);align-self:center;margin-right:12px}
  .axlabel{font-family:var(--mono);font-size:10.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
  .axlabel.x{text-align:center;margin-top:8px}
  .mx{position:relative;aspect-ratio:1.3/1;border:1px solid var(--line);border-radius:12px;background:linear-gradient(90deg,rgba(13,138,91,.06),rgba(220,38,38,.05));overflow:hidden}
  .mx .qd{position:absolute;width:50%;height:50%;padding:12px 14px}
  .mx .q1{top:0;left:0}.mx .q2{top:0;right:0;text-align:right}.mx .q3{bottom:0;left:0;display:flex;align-items:flex-end}.mx .q4{bottom:0;right:0;display:flex;align-items:flex-end;justify-content:flex-end;text-align:right}
  .mx .qt{font-family:var(--mono);font-size:10px;letter-spacing:.06em;text-transform:uppercase;line-height:1.5}
  .mx .q1 .qt{color:var(--green)}.mx .q2 .qt{color:var(--amber)}.mx .q3 .qt{color:var(--muted)}.mx .q4 .qt{color:var(--coral)}
  .mx .axis-x{position:absolute;left:0;right:0;top:50%;height:1px;background:var(--line)}
  .mx .axis-y{position:absolute;top:0;bottom:0;left:50%;width:1px;background:var(--line)}
  .mx .dot{position:absolute;transform:translate(-50%,50%) scale(0);width:13px;height:13px;border-radius:50%;border:2px solid #fff;box-shadow:0 2px 6px rgba(10,23,51,.25);transition:transform .4s cubic-bezier(.34,1.56,.64,1)}
  .mx .dot.show{transform:translate(-50%,50%) scale(1)}
  .mx .dot .tip{position:absolute;bottom:18px;left:50%;transform:translateX(-50%);white-space:nowrap;background:var(--ink);color:#fff;font-size:11px;padding:4px 8px;border-radius:6px;opacity:0;pointer-events:none;transition:.15s;font-family:var(--body)}
  .mx .dot:hover .tip{opacity:1}
  .chips{display:flex;flex-wrap:wrap;gap:9px;margin-top:14px}
  .ct-chip{cursor:pointer;font-family:var(--body);font-size:13.5px;font-weight:500;border:1px solid var(--line);background:var(--bg);color:var(--ink-soft);border-radius:999px;padding:8px 14px;transition:.16s;display:inline-flex;align-items:center;gap:8px}
  .ct-chip:hover{border-color:var(--blue)}
  .ct-chip .pip{width:9px;height:9px;border-radius:50%;background:#cfd5e2}
  .ct-chip.on{background:var(--ink);color:#fff;border-color:var(--ink)}
  .mx-legend{display:flex;flex-wrap:wrap;gap:16px;margin-top:14px;font-size:12.5px;color:var(--ink-soft)}
  .mx-legend span{display:inline-flex;align-items:center;gap:7px}
  .mx-legend i{width:10px;height:10px;border-radius:50%}

  /* Fig 6 chart */
  .chart svg{width:100%;height:auto;display:block;overflow:visible}
  .chart .grid{stroke:var(--line)}
  .chart .axt{fill:var(--muted);font-family:var(--mono);font-size:11px}
  .chart .ser{fill:none;stroke-width:2.5;stroke-linecap:round;stroke-linejoin:round}
  .chart .area{opacity:.12}
  .chart .draw{stroke-dasharray:1;stroke-dashoffset:1;transition:stroke-dashoffset 1.4s ease}
  .chart.in .draw{stroke-dashoffset:0}
  @media(prefers-reduced-motion:reduce){.chart .draw{stroke-dashoffset:0}}
  .chart .endlab{font-family:var(--mono);font-size:12px;font-weight:600}
  .ch-legend{display:flex;gap:20px;margin-top:14px;font-size:13px;color:var(--ink-2)}
  .ch-legend span{display:inline-flex;align-items:center;gap:8px}
  .ch-legend i{width:16px;height:3px;border-radius:2px}

  /* ---- action plan band ---- */
  .section-band{border-top:1px solid var(--line);background:var(--bg-tint)}
  .section-band .wrap{padding:56px 28px}
  .band-head{max-width:64ch}
  .band-head .mono{color:var(--blue);display:block;margin-bottom:12px}
  .band-head h2{font-family:var(--display);font-weight:700;font-size:clamp(26px,3.6vw,38px);letter-spacing:-.02em;line-height:1.08;margin:0 0 12px}
  .band-head p{color:var(--ink-soft);margin:0;max-width:60ch}
  .ap-prog{display:flex;align-items:center;gap:14px;margin:22px 0 6px;max-width:520px}
  .ap-prog .pw{flex:1;height:8px;border-radius:99px;background:var(--bg);border:1px solid var(--line);overflow:hidden}
  .ap-prog .pb{height:100%;width:0;background:var(--blue);transition:width .5s cubic-bezier(.22,1,.36,1)}
  .ap-prog .pn{font-family:var(--mono);font-size:12px;color:var(--ink-soft);white-space:nowrap}
  .ap-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:28px}
  @media(max-width:900px){.ap-grid{grid-template-columns:1fr}}
  .ap-phase{background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:22px 20px}
  .ap-phase .pn{font-family:var(--mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--blue);display:flex;align-items:center;gap:9px;margin-bottom:12px}
  .ap-phase .pn b{width:24px;height:24px;border-radius:7px;background:var(--blue-soft);color:var(--blue);display:grid;place-items:center;font-size:12px}
  .ap-phase h3{font-family:var(--display);font-weight:600;font-size:18px;letter-spacing:-.01em;margin:0 0 14px;color:var(--ink)}
  .ai-item{display:flex;gap:12px;align-items:flex-start;padding:11px 0;border-top:1px solid var(--line-soft);cursor:pointer;font-size:14px;line-height:1.45;color:var(--ink-2)}
  .ai-item:first-of-type{border-top:none}
  .ai-item input{position:absolute;opacity:0;width:0;height:0}
  .ai-item .bx{flex:none;width:20px;height:20px;border:2px solid var(--line);border-radius:6px;display:grid;place-items:center;margin-top:1px;color:#fff;font-size:12px;transition:.16s}
  .ai-item input:checked + .bx{background:var(--green);border-color:var(--green)}
  .ai-item input:checked ~ .tx{color:var(--muted);text-decoration:line-through;text-decoration-color:var(--line)}
  .ai-item .tx b{color:var(--ink);font-weight:600}
  .ap-foot{margin-top:18px;font-size:13.5px;color:var(--ink-soft)}

  /* ---- self-audit (light) ---- */
  .audit-head{text-align:left;max-width:64ch}
  .audit-grid{display:grid;grid-template-columns:1fr 300px;gap:32px;align-items:start;margin-top:28px}
  @media(max-width:840px){.audit-grid{grid-template-columns:1fr}}
  .checks{display:grid;gap:2px}
  .check{display:flex;gap:13px;align-items:flex-start;padding:13px 15px;border-radius:10px;cursor:pointer;transition:.15s;border:1px solid transparent}
  .check:hover{background:var(--bg-tint);border-color:var(--line)}
  .check .cb{flex:none;width:21px;height:21px;border:2px solid var(--line);border-radius:6px;display:grid;place-items:center;margin-top:1px;font-size:12px;color:#fff;transition:.15s}
  .check.on .cb{background:var(--blue);border-color:var(--blue)}
  .check .ct{font-size:15px;line-height:1.45;color:var(--ink-2)}
  .check .ct b{color:var(--ink);font-weight:600}
  .scorecard{background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:24px;position:sticky;top:92px;box-shadow:var(--shadow)}
  .score-num{font-family:var(--display);font-size:58px;font-weight:700;line-height:1;letter-spacing:-.02em;color:var(--ink)}
  .score-num span{font-size:22px;color:var(--muted)}
  .score-ring{height:9px;border-radius:99px;background:var(--bg-tint);border:1px solid var(--line-soft);overflow:hidden;margin:16px 0}
  .score-ring i{display:block;height:100%;width:0;background:var(--blue);transition:width .6s cubic-bezier(.22,1,.36,1)}
  .verdict .mono{color:var(--blue);display:block;margin-bottom:8px}
  .verdict p{font-size:14px;color:var(--ink-soft);margin:0}

  /* ---- final CTA (dark, readable) ---- */
  .cta-wrap{padding:64px 28px 24px;max-width:var(--maxw);margin:0 auto}
  .cta-card{background:var(--bg-deep);color:#fff;border-radius:16px;padding:clamp(30px,5vw,52px);position:relative;overflow:hidden;text-align:center}
  .cta-card:before{content:"";position:absolute;inset:0;background-image:linear-gradient(to right,rgba(255,255,255,.04) 1px,transparent 1px),linear-gradient(to bottom,rgba(255,255,255,.04) 1px,transparent 1px);background-size:40px 40px;-webkit-mask-image:radial-gradient(ellipse 60% 70% at 50% 30%,#000,transparent 70%);mask-image:radial-gradient(ellipse 60% 70% at 50% 30%,#000,transparent 70%)}
  .cta-card>*{position:relative}
  .cta-card .mono{color:var(--amber);display:block;margin-bottom:14px}
  .cta-card h2{font-family:var(--display);font-weight:700;font-size:clamp(26px,4vw,42px);letter-spacing:-.02em;line-height:1.06;margin:0 auto 14px;max-width:20ch}
  .cta-card h2 .serif-em{color:var(--amber)}
  .cta-card p{color:#c4cce0;max-width:56ch;margin:0 auto 28px;font-size:16px}
  .cta-row{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
  .btn-amber{background:var(--amber);color:#fff}
  .btn-amber:hover{background:#b35e05;transform:translateY(-1px)}
  .btn-line-light{background:transparent;color:#fff;border-color:rgba(255,255,255,.3)}
  .btn-line-light:hover{background:rgba(255,255,255,.08);border-color:rgba(255,255,255,.6)}

  footer.site{border-top:1px solid var(--line);margin-top:48px}
  footer.site .wrap{padding:48px 28px 40px;text-align:center}
  .foot-statement{font-family:var(--display);font-weight:700;font-size:clamp(26px,5vw,44px);letter-spacing:-.03em;line-height:1.05;color:var(--ink);margin:0 0 28px}
  .foot-statement .serif-em{color:var(--blue)}
  .foot-row{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:14px;padding-top:24px;border-top:1px solid var(--line);color:var(--muted);font-size:13px}
  .foot-row a{color:var(--ink-soft)}
  .foot-row a:hover{color:var(--ink)}

  .reveal{opacity:0;transform:translateY(16px);transition:opacity .7s ease,transform .7s cubic-bezier(.22,1,.36,1)}
  .reveal.in{opacity:1;transform:none}
  @media(prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}}

  /* ============================================================
     SHARED FIGURE EXTENSIONS (courses 02, 03, 06)
     Built on the same tokens as the original course.
     ============================================================ */

  /* generic staged SVG (cluster maps, redirect maps) reuse .fan */
  .clu .pillar rect{fill:var(--ink);stroke:var(--ink)}
  .clu .pillar text{fill:#fff}
  .clu .spoke rect{fill:var(--bg);stroke:var(--blue);stroke-width:1.4}
  .clu .spoke text{fill:var(--ink-2);font-family:var(--mono);font-size:11.5px}
  .clu .spoke .t{font-family:var(--body);font-size:12.5px;fill:var(--ink-2)}
  .clu .orphan rect{fill:var(--bg);stroke:var(--line);stroke-dasharray:4 3}
  .clu .orphan text{fill:var(--muted)}

  /* radial topic-radius plotter */
  .radius{position:relative;aspect-ratio:1.25/1;border:1px solid var(--line);border-radius:12px;background:radial-gradient(circle at 50% 54%,rgba(30,78,216,.05),transparent 62%);overflow:hidden}
  .radius .ring{position:absolute;left:50%;top:54%;transform:translate(-50%,-50%);border:1px dashed var(--line);border-radius:50%}
  .radius .ring.r1{width:26%;aspect-ratio:1}
  .radius .ring.r2{width:54%;aspect-ratio:1;border-color:#dfe4ee}
  .radius .ring.r3{width:84%;aspect-ratio:1;border-color:#e9edf4}
  .radius .core{position:absolute;left:50%;top:54%;transform:translate(-50%,-50%);background:var(--ink);color:#fff;font-family:var(--mono);font-size:10px;letter-spacing:.05em;text-transform:uppercase;padding:6px 10px;border-radius:999px;white-space:nowrap;z-index:3}
  .radius .rlabel{position:absolute;left:50%;transform:translateX(-50%);font-family:var(--mono);font-size:9.5px;letter-spacing:.05em;text-transform:uppercase;color:var(--muted)}
  .radius .dot{position:absolute;transform:translate(-50%,-50%) scale(0);width:13px;height:13px;border-radius:50%;border:2px solid #fff;box-shadow:0 2px 6px rgba(10,23,51,.25);transition:transform .4s cubic-bezier(.34,1.56,.64,1);z-index:4}
  .radius .dot.show{transform:translate(-50%,-50%) scale(1)}
  .radius .dot .tip{position:absolute;bottom:18px;left:50%;transform:translateX(-50%);white-space:nowrap;background:var(--ink);color:#fff;font-size:11px;padding:4px 8px;border-radius:6px;opacity:0;pointer-events:none;transition:.15s;font-family:var(--body)}
  .radius .dot:hover .tip{opacity:1}

  /* comparison selector (interactive vs static vs image) */
  .cmp-tabs{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:6px}
  .cmp-tab{cursor:pointer;font-family:var(--display);font-weight:600;font-size:14px;border:1px solid var(--line);background:var(--bg);color:var(--ink-soft);border-radius:8px;padding:10px 15px;transition:.16s}
  .cmp-tab:hover{border-color:var(--blue)}
  .cmp-tab.on{background:var(--ink);color:#fff;border-color:var(--ink)}
  .cmp-read{display:grid;gap:11px;margin-top:16px}
  .cmp-attr{display:grid;grid-template-columns:160px 1fr;gap:14px;align-items:center}
  @media(max-width:560px){.cmp-attr{grid-template-columns:1fr;gap:4px}}
  .cmp-attr .lab{font-size:13.5px;color:var(--ink-soft)}
  .cmp-attr .lab b{color:var(--ink);font-weight:600}
  .cmp-meter{height:9px;border-radius:99px;background:var(--bg-tint);border:1px solid var(--line-soft);overflow:hidden;position:relative}
  .cmp-meter i{display:block;height:100%;width:0;border-radius:99px;transition:width .45s cubic-bezier(.22,1,.36,1)}
  .cmp-note{font-size:13.5px;color:var(--ink-2);background:var(--bg-tint);border-left:2px solid var(--blue);padding:11px 13px;margin-top:14px;line-height:1.5}

  /* triage engine (course 06) */
  .triage{display:grid;grid-template-columns:1fr 1fr;gap:20px}
  @media(max-width:620px){.triage{grid-template-columns:1fr}}
  .tri-q{margin-bottom:16px}
  .tri-q .ql{font-family:var(--mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-soft);margin-bottom:9px;display:block}
  .tri-opts{display:flex;gap:8px;flex-wrap:wrap}
  .tri-opt{cursor:pointer;font-family:var(--body);font-size:13.5px;font-weight:500;border:1px solid var(--line);background:var(--bg);color:var(--ink-soft);border-radius:999px;padding:8px 14px;transition:.16s}
  .tri-opt:hover{border-color:var(--blue)}
  .tri-opt.on{background:var(--blue);color:#fff;border-color:var(--blue)}
  .tri-out{background:var(--bg-tint);border:1px solid var(--line);border-radius:12px;padding:22px;display:flex;flex-direction:column;justify-content:center;min-height:200px}
  .tri-out .verdict-tag{display:inline-flex;align-self:flex-start;align-items:center;gap:8px;font-family:var(--display);font-weight:700;font-size:18px;letter-spacing:-.01em;padding:8px 14px;border-radius:8px;margin-bottom:12px}
  .tri-out .vd{font-size:14.5px;color:var(--ink-2);line-height:1.55;margin:0}
  .tri-out .vd b{color:var(--ink)}
  .tag-keep{background:var(--blue-soft);color:var(--blue)}
  .tag-refresh{background:#dff1e8;color:var(--green)}
  .tag-redirect{background:var(--amber-soft);color:#a8480a}
  .tag-noindex{background:#eef1f7;color:var(--ink-soft)}
  .tag-pivot{background:#ede7fb;color:#5b3ec8}
  .tag-wait{background:#eef1f7;color:var(--muted)}

  /* small distribution bars (audit-grounded) */
  .dist{display:grid;gap:10px;margin-top:4px}
  .dist .drow{display:grid;grid-template-columns:120px 1fr 42px;gap:12px;align-items:center}
  @media(max-width:560px){.dist .drow{grid-template-columns:96px 1fr 34px}}
  .dist .dlab{font-size:13px;color:var(--ink-2)}
  .dist .dtrk{height:22px;border-radius:6px;background:var(--bg-tint);border:1px solid var(--line-soft);overflow:hidden}
  .dist .dfill{height:100%;width:0;border-radius:6px;transition:width 1s cubic-bezier(.22,1,.36,1)}
  .dist .dval{font-family:var(--mono);font-size:12px;color:var(--ink-soft);text-align:right}

  /* annotated chart callouts */
  .anno-note{font-family:var(--mono);font-size:11px;fill:var(--ink-soft)}
  .anno-line{stroke:var(--amber);stroke-width:1;stroke-dasharray:3 3}

  /* before/after generic panel */
  .ba-cols{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:4px}
  @media(max-width:560px){.ba-cols{grid-template-columns:1fr}}
  .ba-col{border:1px solid var(--line);border-radius:11px;padding:16px;background:var(--bg)}
  .ba-col h5{margin:0 0 9px;font-family:var(--mono);font-size:10.5px;letter-spacing:.07em;text-transform:uppercase}
  .ba-col.before h5{color:var(--muted)}
  .ba-col.after h5{color:var(--green)}
  .ba-col p{margin:0;font-size:14px;color:var(--ink-2);line-height:1.5}
  .ba-col .pill{display:inline-block;font-family:var(--mono);font-size:10px;color:var(--ink-soft);background:var(--bg-tint);border:1px solid var(--line);border-radius:999px;padding:3px 9px;margin-top:10px}

  /* ============================================================
     DESIGN PASS · accessibility + upgraded figures
     ============================================================ */
  :where(button,a,.check,.pat,.ct-chip,.tri-opt,.cmp-tab,.rad-chip,.gf-gate):focus-visible{outline:2px solid var(--blue);outline-offset:2px;border-radius:8px}
  .panel{transition:box-shadow .25s ease}

  /* Course 02 · Fig 01 three-filter gate */
  .gateflow{display:grid;gap:16px}
  .gf-meter{height:6px;border-radius:99px;background:var(--bg-tint);border:1px solid var(--line-soft);overflow:hidden}
  .gf-meter i{display:block;height:100%;width:0;background:linear-gradient(90deg,#0d8a5b,#1e4ed8);transition:width .5s cubic-bezier(.22,1,.36,1)}
  .gf-gates{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
  @media(max-width:600px){.gf-gates{grid-template-columns:1fr}}
  .gf-gate{position:relative;text-align:left;cursor:pointer;font-family:inherit;background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:16px 44px 14px 16px;transition:.18s}
  .gf-gate:hover{border-color:var(--blue)}
  .gf-gate.on{border-color:#0d8a5b;background:#f3faf6;box-shadow:0 12px 26px -20px rgba(13,138,91,.55)}
  .gf-gate .gn{font-family:var(--mono);font-size:11px;letter-spacing:.04em;color:var(--muted)}
  .gf-gate.on .gn{color:#0d8a5b}
  .gf-gate h5{margin:6px 0 3px;font-family:var(--display);font-size:15.5px;font-weight:600;color:var(--ink);letter-spacing:-.01em}
  .gf-gate p{margin:0;font-size:12.5px;color:var(--ink-soft);line-height:1.42}
  .gf-gate .gx{position:absolute;top:14px;right:14px;width:23px;height:23px;border-radius:50%;border:2px solid var(--line);display:grid;place-items:center;color:#fff;font-size:12px;line-height:0;transition:.18s}
  .gf-gate.on .gx{background:#0d8a5b;border-color:#0d8a5b}
  .gf-gate .gx svg{width:13px;height:13px;display:block;opacity:0;transition:.18s}
  .gf-gate.on .gx svg{opacity:1}
  .gf-out2{background:var(--bg-tint);border:1px solid var(--line);border-radius:12px;padding:18px 20px}
  .gf-out2 .verdict-tag{display:inline-flex;align-items:center;gap:8px;font-family:var(--display);font-weight:700;font-size:17px;letter-spacing:-.01em;padding:7px 13px;border-radius:8px;margin-bottom:11px}
  .gf-out2 p{margin:0;font-size:14.5px;color:var(--ink-2);line-height:1.55}

  /* Course 06 · Fig 03 triage decision grid */
  .tri-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:20px}
  .tri-gridhead{font-family:var(--mono);font-size:10.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);margin-top:18px}
  .tri-cell{position:relative;border:1px solid var(--line);border-radius:12px;padding:15px;background:var(--bg);transition:transform .25s cubic-bezier(.22,1,.36,1),box-shadow .25s ease,border-color .2s,opacity .2s;opacity:.6}
  .tri-cell .tc-meta{font-family:var(--mono);font-size:10px;letter-spacing:.04em;text-transform:uppercase;color:var(--muted);margin-bottom:8px}
  .tri-cell .tc-act{display:inline-flex;align-items:center;gap:8px;font-family:var(--display);font-weight:700;font-size:15.5px;color:var(--ink);letter-spacing:-.01em}
  .tri-cell .tc-act .pin{width:9px;height:9px;border-radius:50%;flex:none}
  .tri-cell.active{opacity:1;border-color:var(--blue);box-shadow:0 18px 36px -20px rgba(30,78,216,.55);transform:translateY(-3px)}
  .tri-cell.active:before{content:"Your page";position:absolute;top:-9px;right:12px;font-family:var(--mono);font-size:9.5px;letter-spacing:.05em;text-transform:uppercase;background:var(--blue);color:#fff;padding:3px 8px;border-radius:999px}

  /* Course 06 · Fig 01 lever cards with icon accent */
  .ba-col .lever-ic{width:38px;height:38px;border-radius:10px;display:grid;place-items:center;margin-bottom:12px;background:var(--blue-soft);color:var(--blue)}
  .ba-col .lever-ic svg{width:20px;height:20px;display:block}