:root {
      color-scheme: light dark;
      --paper: #f3f1ea;
      --panel: #fffdf7;
      --ink: #161918;
      --muted: #565d59;
      --line: #c9ccc3;
      --line-strong: #8e958f;
      --accent: #d85d2d;
      --accent-deep: #a43e19;
      --signal: #d9bb2f;
      --signal-soft: #f5eab8;
      --ok: #276749;
      --danger: #a23328;
      --shadow: 0 18px 50px rgba(25, 31, 28, .09);
    }
    @media (prefers-color-scheme: dark) {
      :root {
        --paper: #111413;
        --panel: #181c1a;
        --ink: #eef0ea;
        --muted: #b3bbb5;
        --line: #353c38;
        --line-strong: #68716b;
        --accent: #ff7a45;
        --accent-deep: #ff9b72;
        --signal: #e5c84f;
        --signal-soft: #3a351b;
        --ok: #76cf9f;
        --danger: #ff897d;
        --shadow: 0 20px 56px rgba(0, 0, 0, .3);
      }
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      background:
        linear-gradient(var(--line) 1px, transparent 1px),
        linear-gradient(90deg, var(--line) 1px, transparent 1px),
        var(--paper);
      background-size: 48px 48px;
      color: var(--ink);
      font-family: "Aptos", "Segoe UI", sans-serif;
      line-height: 1.5;
    }
    button, input, select { font: inherit; }
    a { color: inherit; }
    .shell { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }
    .topline {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 24px;
      padding: 18px 0;
      border-bottom: 1px solid var(--line-strong);
    }
    .credential {
      display: flex;
      align-items: center;
      gap: 11px;
      color: var(--muted);
      font-size: .83rem;
      font-weight: 700;
    }
    .credential::before {
      content: "";
      width: 28px;
      height: 3px;
      background: var(--accent);
      box-shadow: 9px 7px 0 var(--signal);
    }
    .topline nav { display: flex; gap: 22px; font-size: .83rem; font-weight: 700; }
    .topline a { text-decoration: none; }
    .topline a:hover { color: var(--accent); }

    .hero {
      display: grid;
      grid-template-columns: 1.2fr .8fr;
      align-items: end;
      min-height: 560px;
      padding: 72px 0 56px;
      border-bottom: 1px solid var(--line-strong);
    }
    .hero-copy { max-width: 790px; }
    .eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      margin: 0 0 25px;
      padding: 7px 10px;
      border: 1px solid var(--line-strong);
      background: var(--paper);
      color: var(--muted);
      font-family: "SFMono-Regular", Consolas, monospace;
      font-size: .72rem;
      font-weight: 700;
      letter-spacing: .06em;
      text-transform: uppercase;
    }
    .eyebrow b { color: var(--accent); }
    h1 {
      margin: 0;
      max-width: 820px;
      font-family: Georgia, "Times New Roman", serif;
      font-size: clamp(3.4rem, 8vw, 7.5rem);
      line-height: .88;
      letter-spacing: -.07em;
      font-weight: 700;
    }
    h1 span { display: block; margin-left: .32em; color: var(--accent); }
    .lede {
      max-width: 670px;
      margin: 36px 0 0;
      color: var(--muted);
      font-size: clamp(1.05rem, 1.8vw, 1.35rem);
      line-height: 1.55;
    }
    .hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-height: 48px;
      padding: 0 18px;
      border: 1px solid var(--ink);
      background: var(--ink);
      color: var(--paper);
      font-weight: 800;
      text-decoration: none;
      cursor: pointer;
    }
    .btn.secondary { background: transparent; color: var(--ink); }
    .btn:hover { background: var(--accent); border-color: var(--accent); color: #fff; }
    .hero-diagram {
      display: grid;
      place-items: center;
      min-height: 340px;
      position: relative;
    }
    .logo-frame {
      width: min(100%, 390px);
      aspect-ratio: 1;
      border: 2px solid var(--ink);
      background: #07121f;
      box-shadow: 14px 14px 0 var(--signal), var(--shadow);
      overflow: hidden;
      transform: rotate(1.5deg);
    }
    .logo-frame video {
      display: block;
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .section { padding: 88px 0; }
    .section-head {
      display: grid;
      grid-template-columns: .72fr 1.28fr;
      gap: 40px;
      align-items: end;
      margin-bottom: 34px;
    }
    .section-label {
      margin: 0;
      color: var(--accent);
      font-family: "SFMono-Regular", Consolas, monospace;
      font-size: .77rem;
      font-weight: 800;
      letter-spacing: .08em;
      text-transform: uppercase;
    }
    h2 {
      margin: 0;
      max-width: 780px;
      font-family: Georgia, "Times New Roman", serif;
      font-size: clamp(2.2rem, 5vw, 4.6rem);
      line-height: 1;
      letter-spacing: -.045em;
    }
    .section-intro { max-width: 670px; margin: 18px 0 0; color: var(--muted); font-size: 1.05rem; }

    .calculator {
      display: grid;
      grid-template-columns: minmax(0, 1.08fr) minmax(340px, .92fr);
      border: 1px solid var(--line-strong);
      background: var(--panel);
      box-shadow: var(--shadow);
    }
    .calc-form { padding: 32px; border-right: 1px solid var(--line-strong); }
    .preset-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 26px; }
    .preset {
      padding: 8px 11px;
      border: 1px solid var(--line);
      background: transparent;
      color: var(--muted);
      font-family: "SFMono-Regular", Consolas, monospace;
      font-size: .76rem;
      font-weight: 700;
      cursor: pointer;
    }
    .preset:hover, .preset:focus-visible { border-color: var(--accent); color: var(--accent); }
    .fields { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
    .field { min-width: 0; }
    .field.full { grid-column: 1 / -1; }
    label { display: block; margin-bottom: 7px; font-size: .78rem; font-weight: 800; }
    .input-wrap { position: relative; }
    input, select {
      width: 100%;
      min-height: 48px;
      border: 1px solid var(--line-strong);
      border-radius: 0;
      background: var(--paper);
      color: var(--ink);
      padding: 11px 40px 11px 12px;
      outline: none;
    }
    select { padding-right: 12px; }
    input:focus, select:focus { border-color: var(--accent); box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 24%, transparent); }
    .unit { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); color: var(--muted); font: 700 .76rem "SFMono-Regular", Consolas, monospace; pointer-events: none; }
    .field-note { margin-top: 6px; color: var(--muted); font-size: .72rem; }
    .error { min-height: 1.4em; margin: 18px 0 0; color: var(--danger); font-weight: 700; font-size: .85rem; }

    .result {
      display: flex;
      flex-direction: column;
      min-height: 100%;
      padding: 32px;
      background: var(--ink);
      color: var(--paper);
    }
    @media (prefers-color-scheme: dark) {
      .result { background: #eef0ea; color: #141816; }
    }
    .result-label { font: 800 .74rem "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; text-transform: uppercase; opacity: .68; }
    .result-main { margin-top: 22px; }
    .result-number { font-family: Georgia, "Times New Roman", serif; font-size: clamp(4.7rem, 10vw, 7.6rem); line-height: .82; letter-spacing: -.07em; }
    .result-number small { margin-left: 6px; font-family: "SFMono-Regular", Consolas, monospace; font-size: .95rem; letter-spacing: 0; }
    .result-status {
      display: inline-flex;
      align-items: center;
      gap: 9px;
      margin-top: 18px;
      font-weight: 800;
    }
    .status-dot { width: 11px; aspect-ratio: 1; border-radius: 50%; background: var(--ok); }
    .status-dot.warn { background: var(--signal); }
    .status-dot.bad { background: var(--danger); }
    .result-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; margin-top: 34px; background: color-mix(in srgb, currentColor 18%, transparent); }
    .metric { padding: 18px 14px; background: inherit; }
    .metric:nth-child(n) { background: color-mix(in srgb, var(--ink) 94%, var(--paper)); }
    @media (prefers-color-scheme: dark) { .metric:nth-child(n) { background: #e2e5de; } }
    .metric span { display: block; font: 700 .7rem "SFMono-Regular", Consolas, monospace; text-transform: uppercase; opacity: .62; }
    .metric strong { display: block; margin-top: 4px; font-size: 1.15rem; }
    .recommendation {
      margin-top: 22px;
      padding-top: 20px;
      border-top: 1px solid color-mix(in srgb, currentColor 25%, transparent);
      font-size: .92rem;
    }
    .recommendation strong { color: var(--signal); }
    @media (prefers-color-scheme: dark) { .recommendation strong { color: #8a6810; } }
    .formula {
      margin-top: auto;
      padding-top: 28px;
      font: .72rem/1.65 "SFMono-Regular", Consolas, monospace;
      opacity: .68;
    }

    .method-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line-strong); border-left: 1px solid var(--line-strong); }
    .method-item { min-height: 210px; padding: 25px; border-right: 1px solid var(--line-strong); border-bottom: 1px solid var(--line-strong); background: var(--panel); }
    .method-num { color: var(--accent); font: 800 .76rem "SFMono-Regular", Consolas, monospace; }
    .method-item h3 { margin: 45px 0 10px; font-family: Georgia, "Times New Roman", serif; font-size: 1.35rem; }
    .method-item p { margin: 0; color: var(--muted); font-size: .91rem; }

    .guide-index {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      border-top: 1px solid var(--line-strong);
      border-left: 1px solid var(--line-strong);
      margin-bottom: 54px;
    }
    .guide-index a {
      min-height: 150px;
      padding: 22px;
      border-right: 1px solid var(--line-strong);
      border-bottom: 1px solid var(--line-strong);
      background: var(--panel);
      text-decoration: none;
    }
    .guide-index a:hover, .guide-index a:focus-visible { background: var(--signal-soft); }
    .guide-index span { color: var(--accent); font: 800 .72rem "SFMono-Regular", Consolas, monospace; }
    .guide-index strong { display: block; margin-top: 28px; font: 700 1.25rem/1.15 Georgia, "Times New Roman", serif; }
    .guide-index small { display: block; margin-top: 8px; color: var(--muted); }

    .guide-article {
      display: grid;
      grid-template-columns: minmax(170px, .48fr) minmax(0, 1.52fr);
      gap: clamp(28px, 5vw, 74px);
      padding: 64px 0;
      border-top: 1px solid var(--line-strong);
      scroll-margin-top: 20px;
    }
    .guide-rail { align-self: start; position: sticky; top: 24px; }
    .guide-number { color: var(--accent); font: 800 .75rem "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; }
    .guide-rail p { margin: 16px 0 0; color: var(--muted); font-size: .78rem; }
    .guide-body { max-width: 820px; }
    .guide-title { margin: 0; font: 700 clamp(2.25rem, 5vw, 4.1rem)/.98 Georgia, "Times New Roman", serif; letter-spacing: -.045em; }
    .guide-deck { margin: 20px 0 38px; color: var(--muted); font-size: 1.13rem; line-height: 1.65; }
    .guide-body h4 { margin: 38px 0 12px; font: 700 1.45rem/1.2 Georgia, "Times New Roman", serif; }
    .guide-body p { margin: 0 0 18px; }
    .guide-body ul, .guide-body ol { margin: 0 0 24px; padding-left: 1.25rem; }
    .guide-body li { margin: 9px 0; padding-left: 5px; }
    .guide-body li::marker { color: var(--accent); font-weight: 800; }
    .guide-body strong { font-weight: 800; }
    .guide-note {
      margin: 30px 0;
      padding: 22px 24px;
      border-top: 3px solid var(--signal);
      border-bottom: 1px solid var(--line-strong);
      background: var(--panel);
    }
    .guide-note p:last-child { margin-bottom: 0; }
    .guide-note-label { color: var(--accent); font: 800 .72rem "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; text-transform: uppercase; }
    .pathway {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      margin: 28px 0 34px;
      border-top: 1px solid var(--line-strong);
      border-left: 1px solid var(--line-strong);
    }
    .pathway div { padding: 18px; border-right: 1px solid var(--line-strong); border-bottom: 1px solid var(--line-strong); background: var(--panel); }
    .pathway b { display: block; color: var(--accent); font: 800 .7rem "SFMono-Regular", Consolas, monospace; }
    .pathway span { display: block; margin-top: 18px; font-weight: 800; }
    .formula-band {
      display: grid;
      grid-template-columns: .65fr 1.35fr;
      gap: 24px;
      align-items: center;
      margin: 28px 0 32px;
      padding: 26px;
      background: var(--ink);
      color: var(--paper);
    }
    @media (prefers-color-scheme: dark) { .formula-band { background: #eef0ea; color: #141816; } }
    .formula-band code { font: 800 clamp(1.8rem, 5vw, 3.4rem)/1 "SFMono-Regular", Consolas, monospace; color: var(--signal); }
    @media (prefers-color-scheme: dark) { .formula-band code { color: #8a6810; } }
    .formula-band p { margin: 0; }

    .authority {
      display: grid;
      grid-template-columns: 1.1fr .9fr;
      border-top: 1px solid var(--line-strong);
      border-bottom: 1px solid var(--line-strong);
      background: var(--signal-soft);
    }
    .authority-copy { padding: 70px max(30px, 6vw); }
    .authority-copy blockquote { margin: 0; font-family: Georgia, "Times New Roman", serif; font-size: clamp(2rem, 4vw, 3.5rem); line-height: 1.08; letter-spacing: -.035em; }
    .authority-copy p { margin: 28px 0 0; max-width: 650px; color: var(--muted); }
    .experience {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      border-left: 1px solid var(--line-strong);
    }
    .experience div { display: flex; flex-direction: column; justify-content: flex-end; min-height: 220px; padding: 30px; border-right: 1px solid var(--line-strong); border-bottom: 1px solid var(--line-strong); }
    .experience strong { font-family: Georgia, "Times New Roman", serif; font-size: 3.5rem; line-height: 1; color: var(--accent); }
    .experience span { margin-top: 8px; font-size: .82rem; font-weight: 800; }

    .bench { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
    .bench article { padding: 26px 0; border-top: 4px solid var(--ink); }
    .bench h3 { margin: 0 0 10px; font-family: Georgia, "Times New Roman", serif; font-size: 1.45rem; }
    .bench p { margin: 0; color: var(--muted); font-size: .9rem; }
    .bench .tag { display: inline-block; margin-top: 22px; color: var(--accent); font: 800 .7rem "SFMono-Regular", Consolas, monospace; text-transform: uppercase; }

    footer { padding: 34px 0 max(34px, env(safe-area-inset-bottom)); border-top: 1px solid var(--line-strong); }
    .footer-inner { display: flex; justify-content: space-between; gap: 25px; color: var(--muted); font-size: .78rem; }
    .footer-inner strong { color: var(--ink); }


    .tool-switcher {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      margin: 0 0 20px;
      border-top: 1px solid var(--line-strong);
      border-left: 1px solid var(--line-strong);
    }
    .tool-switcher a {
      min-height: 58px;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 10px 14px;
      border-right: 1px solid var(--line-strong);
      border-bottom: 1px solid var(--line-strong);
      background: var(--paper);
      font-size: .8rem;
      font-weight: 800;
      text-align: center;
      text-decoration: none;
    }
    .tool-switcher a[aria-current="page"] { background: var(--signal); color: #161918; }
    .calc-assumptions {
      margin: 20px 0 0;
      padding: 16px 0 0;
      border-top: 1px solid var(--line);
      color: var(--muted);
      font-size: .76rem;
      line-height: 1.55;
    }
    .calc-assumptions a { color: var(--accent); font-weight: 800; text-underline-offset: 3px; }
    .conductor-groups { display: grid; gap: 12px; grid-column: 1 / -1; }
    .conductor-group {
      display: grid;
      grid-template-columns: 88px 1fr;
      gap: 12px;
      padding: 14px;
      border: 1px solid var(--line);
      background: color-mix(in srgb, var(--paper) 70%, var(--panel));
    }
    .conductor-group legend {
      grid-column: 1 / -1;
      padding: 0;
      color: var(--accent);
      font: 800 .72rem "SFMono-Regular", Consolas, monospace;
      letter-spacing: .06em;
      text-transform: uppercase;
    }
    .conductor-group .field { min-width: 0; }
    .result-number.gauge-result { font-size: clamp(3.6rem, 8vw, 6.5rem); }
    .result-number.conduit-result { font-size: clamp(4.1rem, 9vw, 7rem); }
    .source-row { margin-top: 18px; color: var(--muted); font-size: .76rem; }
    .source-row a { color: var(--accent); font-weight: 800; }

    @media (max-width: 860px) {
      .hero { grid-template-columns: 1fr; min-height: auto; gap: 55px; padding-top: 54px; }
      .hero-diagram { min-height: 300px; }
      .logo-frame { width: min(390px, 78vw); }
      .section-head { grid-template-columns: 1fr; gap: 14px; }
      .calculator { grid-template-columns: 1fr; }
      .calc-form { border-right: 0; border-bottom: 1px solid var(--line-strong); }
      .guide-article { grid-template-columns: 1fr; gap: 22px; }
      .guide-rail { position: static; }
      .pathway { grid-template-columns: repeat(2, 1fr); }
      .authority { grid-template-columns: 1fr; }
      .experience { border-left: 0; border-top: 1px solid var(--line-strong); }
    }
    @media (max-width: 620px) {
      .shell { width: min(100% - 24px, 1180px); }
      .topline { align-items: flex-start; }
      .credential { max-width: 200px; }
      .topline nav a:not([href="#guides"]) { display: none; }
      .hero { padding: 44px 0 48px; }
      h1 { font-size: clamp(3.25rem, 17vw, 5.2rem); }
      .hero-diagram { overflow: hidden; }
      .logo-frame { width: min(330px, calc(100vw - 54px)); box-shadow: 10px 10px 0 var(--signal), var(--shadow); }
      .section { padding: 62px 0; }
      .fields { grid-template-columns: 1fr; }
      .field.full { grid-column: auto; }
      .calc-form, .result { padding: 24px 18px; }
      .result { min-height: 520px; }
      .result-grid { grid-template-columns: 1fr; }
      .method-grid { grid-template-columns: 1fr; }
      .method-item { min-height: 180px; }
      .method-item h3 { margin-top: 34px; }
      .guide-index { grid-template-columns: 1fr; margin-bottom: 34px; }
      .guide-index a { min-height: 118px; }
      .guide-index strong { margin-top: 18px; }
      .guide-article { padding: 48px 0; }
      .guide-deck { font-size: 1.02rem; }
      .pathway { grid-template-columns: 1fr; }
      .formula-band { grid-template-columns: 1fr; padding: 22px 18px; }
      .authority-copy { padding: 52px 24px; }
      .experience { grid-template-columns: 1fr; }
      .experience div { min-height: 155px; }
      .bench { grid-template-columns: 1fr; }
      .tool-switcher { grid-template-columns: 1fr; }
      .conductor-group { grid-template-columns: 1fr; }
      .footer-inner { flex-direction: column; }
    }
    @media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
  
.topic-media{margin:32px 0}.topic-media img,.topic-media video{display:block;width:100%;max-height:560px;object-fit:cover;border:1px solid var(--line-strong);background:#07121f}.topic-media figcaption{margin-top:8px;color:var(--muted);font-size:.88rem}.guide-back{display:inline-block;margin-bottom:28px;color:var(--accent);font-weight:800;text-decoration-thickness:2px;text-underline-offset:4px}.guide-level{margin-top:48px}.guide-level h3{margin:0 0 14px;padding-bottom:10px;border-bottom:3px solid var(--signal);font-family:"SFMono-Regular",Consolas,monospace;font-size:1.25rem;letter-spacing:.04em;text-transform:uppercase}.ghost-credit{display:inline-flex;align-items:center;gap:8px;white-space:nowrap}.ghost-credit img{width:28px;height:28px;border:1px solid var(--line-strong);border-radius:50%;object-fit:cover}@media(max-width:720px){.topline{align-items:flex-start}.topline nav{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:8px 12px}.topline nav a{display:inline!important;font-size:.72rem}.guide-page .guide-article{display:block}.guide-page .guide-rail{margin-bottom:24px}}