:root{
    color-scheme: light dark;
    /* Brand palette supplied by the owner (brand board, Oct 2026):
       Primary Blue #2563EB leads, Success Green #16A34A secondary,
       Warm Yellow #FBBF24 + Soft Coral #F87171 as warm accents,
       Purple #8B5CF6 as a sparing feature accent, Dark Navy #0F172A text,
       Light Background #F8FAFC, pastel tints for cards/sections. */
    --bg:#F8FAFC; --surface:#ffffff; --surface-2:#EFF6FF; --ink:#0F172A; --ink-2:#64748B;
    --line:#E2E8F0; --brand:#2563EB; --brand-strong:#1D4ED8; --brand-soft:#DBEAFE;
    --accent:#16A34A; --accent-soft:#DCFCE7; --sun:#FBBF24; --sun-soft:#FEF3C7;
    --coral:#F87171; --coral-soft:#FEE2E2; --purple:#8B5CF6; --purple-soft:#EDE9FE; --danger:#DC2626;
    --shadow:0 1px 2px rgba(15,23,42,.05),0 10px 26px -12px rgba(37,99,235,.20);
    --radius:16px;
  }
  @media (prefers-color-scheme: dark){
    :root{
      --bg:#0B1220; --surface:#111C30; --surface-2:#16263F; --ink:#F1F5F9; --ink-2:#94A3B8;
      --line:#24344D; --brand:#60A5FA; --brand-strong:#93C5FD; --brand-soft:#1E3A5F;
      --accent:#4ADE80; --accent-soft:#14532D; --sun:#FBBF24; --sun-soft:#453208;
      --coral:#FCA5A5; --coral-soft:#4C1D1D; --purple:#C4B5FD; --purple-soft:#2E1065; --danger:#FCA5A5;
      --shadow:0 1px 2px rgba(0,0,0,.45),0 10px 26px -12px rgba(0,0,0,.65);
    }
  }
  *{box-sizing:border-box}
  html{scroll-behavior:smooth}
  body{margin:0;background:var(--bg);color:var(--ink);font-family:"Inter","Nunito Sans",system-ui,-apple-system,"Segoe UI",sans-serif;font-size:16.5px;line-height:1.6;-webkit-font-smoothing:antialiased}
  h1,h2,h3{font-family:"Nunito","Inter",system-ui,sans-serif;font-weight:800;line-height:1.15;margin:0;letter-spacing:.1px}
  a{color:var(--brand);text-decoration-thickness:1px;text-underline-offset:3px}
  .wrap{max-width:1120px;margin:0 auto;padding:0 20px}
  /* header */
  header.site{position:sticky;top:0;z-index:40;background:color-mix(in srgb,var(--bg) 92%,transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
  .nav{display:flex;align-items:center;gap:26px;padding:13px 0}
  .logo{display:flex;align-items:center;text-decoration:none}
  .logo-full{height:58px;width:auto;max-width:min(300px,72vw);display:block}
  @media (max-width:760px){.logo-full{height:50px}}
  nav.links{display:flex;gap:22px;margin-left:auto}
  nav.links a{color:var(--ink);text-decoration:none;font-weight:500;font-size:15.5px}
  nav.links a:hover{color:var(--brand)}
  .nav-cta{margin-left:6px;background:#2563EB;color:#fff !important;padding:8px 16px;border-radius:9px}
  .menu-btn{display:none;margin-left:auto;background:none;border:1px solid var(--line);border-radius:9px;padding:7px 11px;color:var(--ink);cursor:pointer}
  @media (max-width:760px){
    nav.links{display:none;position:absolute;left:0;right:0;top:100%;background:var(--surface);border-bottom:1px solid var(--line);flex-direction:column;padding:14px 20px 18px;gap:14px}
    nav.links.open{display:flex}
    .menu-btn{display:block}
    .nav-cta{margin-left:0;text-align:center}
  }
  /* hero */
  .hero{padding:48px 0 34px;background:linear-gradient(180deg,var(--brand-soft) 0%,transparent 82%)}
  .hero-grid{display:grid;grid-template-columns:1.02fr .98fr;gap:38px;align-items:center}
  @media (max-width:880px){.hero-grid{grid-template-columns:1fr}}
  .hero h1{font-size:clamp(32px,5.2vw,50px);max-width:16ch}
  .hero h1 em{font-style:normal;color:var(--brand);border-bottom:5px solid var(--sun);border-radius:2px}
  .photo{width:100%;height:auto;display:block;border-radius:18px;box-shadow:var(--shadow);object-fit:cover}
  .photo-card{position:relative}
  .photo-badge{position:absolute;left:14px;bottom:14px;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:10px 14px;box-shadow:var(--shadow);max-width:82%}
  .photo-badge b{display:block;font-size:14.5px}
  .photo-badge span{font-size:13px;color:var(--ink-2)}
  /* pastel feature mini-cards (brand-board style) */
  .mini-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
  @media (max-width:900px){.mini-grid{grid-template-columns:1fr 1fr}}
  @media (max-width:520px){.mini-grid{grid-template-columns:1fr}}
  .mini{border-radius:14px;padding:18px;text-decoration:none;color:var(--ink);display:block}
  .mini .icon{width:40px;height:40px;border-radius:10px;background:rgba(255,255,255,.7);display:grid;place-items:center}
  @media (prefers-color-scheme: dark){.mini .icon{background:rgba(0,0,0,.28)}}
  .mini h3{font-size:17.5px;margin:9px 0 5px}
  .mini p{margin:0;color:var(--ink-2);font-size:14.5px}
  .tint-blue{background:var(--brand-soft)} .tint-blue .icon{color:var(--brand-strong)}
  .tint-green{background:var(--accent-soft)} .tint-green .icon{color:var(--accent)}
  .tint-yellow{background:var(--sun-soft)} .tint-yellow .icon{color:#B45309}
  @media (prefers-color-scheme: dark){.tint-yellow .icon{color:var(--sun)}}
  .tint-coral{background:var(--coral-soft)} .tint-coral .icon{color:#DC2626}
  @media (prefers-color-scheme: dark){.tint-coral .icon{color:var(--coral)}}
  /* two-column photo + text split */
  .split{display:grid;grid-template-columns:1fr 1fr;gap:32px;align-items:center}
  @media (max-width:820px){.split{grid-template-columns:1fr}}
  .split h2{font-size:clamp(24px,3.4vw,32px);margin:10px 0 10px}
  .split p{color:var(--ink-2);margin:0 0 16px}
  /* brand swatches (About page) */
  .sw-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(138px,1fr));gap:12px;margin:16px 0 6px}
  .sw{border:1px solid var(--line);border-radius:12px;overflow:hidden;background:var(--surface)}
  .sw i{display:block;height:50px}
  .sw div{padding:9px 11px;font-size:12.5px;color:var(--ink-2)}
  .sw b{display:block;font-size:13.5px;color:var(--ink)}
  /* logo showcase + stack note (About page) */
  .logo-show{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:18px 0 8px}
  @media (max-width:620px){.logo-show{grid-template-columns:1fr}}
  .logo-tile{border:1px solid var(--line);border-radius:var(--radius);padding:26px 20px;display:grid;place-items:center;text-align:center;gap:12px}
  .logo-tile.light{background:#ffffff}
  .logo-tile.dark{background:#0F172A}
  .logo-tile img.full{width:min(300px,88%);height:auto}
  .logo-tile img.mark{width:76px;height:76px}
  .logo-tile p{margin:0;font-size:13.5px}
  .logo-tile.light p{color:#64748B}.logo-tile.dark p{color:#CBD5E1}
  .stack-note{background:var(--accent-soft);border:1px solid var(--accent);border-radius:var(--radius);padding:20px 22px;margin:20px 0}
  .stack-note h3{margin:0 0 8px;color:var(--brand-strong)}
  .stack-note p{margin:0 0 10px}.stack-note p:last-child{margin-bottom:0}
  .hero p.lede{font-size:19px;color:var(--ink-2);max-width:62ch;margin:18px 0 26px}
  .hero-stats{display:flex;flex-wrap:wrap;gap:10px 26px;font-size:14.5px;color:var(--ink-2)}
  .hero-stats b{color:var(--ink)}
  /* buttons & chips */
  .btn{display:inline-block;background:linear-gradient(135deg,#2563EB,#1D4ED8);color:#fff;box-shadow:0 6px 16px -8px rgba(37,99,235,.55);text-decoration:none;font-weight:600;padding:11px 20px;border-radius:10px;border:0;cursor:pointer;font-size:15.5px}
  .btn.secondary{background:var(--surface);color:var(--ink);border:1px solid var(--line)}
  .chip{display:inline-block;background:var(--brand-soft);color:var(--brand-strong);font-size:12.5px;font-weight:700;letter-spacing:.05em;text-transform:uppercase;padding:4px 11px;border-radius:99px}
  .chip.sun{background:var(--sun-soft);color:#8a5a00}
  @media (prefers-color-scheme: dark){.chip.sun{color:var(--sun)}}
  /* sections */
  section.block{padding:38px 0}
  .section-head{max-width:70ch;margin-bottom:22px}
  .section-head h2{font-size:clamp(25px,3.6vw,34px);margin-bottom:8px}
  .section-head p{color:var(--ink-2);margin:0}
  /* cards */
  .grid{display:grid;gap:18px}
  .grid.c3{grid-template-columns:repeat(3,1fr)}
  .grid.c2{grid-template-columns:repeat(2,1fr)}
  @media (max-width:900px){.grid.c3{grid-template-columns:1fr 1fr}}
  @media (max-width:620px){.grid.c3,.grid.c2{grid-template-columns:1fr}}
  .card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow)}
  .card h3{font-size:21px;margin:10px 0 8px}
  .card p{color:var(--ink-2);margin:0 0 14px;font-size:15.5px}
  .card .icon{width:44px;height:44px;border-radius:11px;background:var(--brand-soft);display:grid;place-items:center;color:var(--brand)}
  .grid .card:nth-child(3n+2) .icon{background:var(--accent-soft);color:var(--accent)}
  .grid .card:nth-child(3n) .icon{background:var(--sun-soft);color:#B45309}
  @media (prefers-color-scheme: dark){.grid .card:nth-child(3n) .icon{color:var(--sun)}}
  .grid .card:nth-child(4n) .icon{background:var(--coral-soft);color:#DC2626}
  @media (prefers-color-scheme: dark){.grid .card:nth-child(4n) .icon{color:var(--coral)}}
  .grid .card:nth-child(5n) .icon{background:var(--purple-soft);color:var(--purple)}
  .card a.go{font-weight:600;text-decoration:none}
  .card a.go::after{content:" →"}
  /* calculator */
  .calc{display:grid;grid-template-columns:1fr 380px;gap:22px;align-items:start}
  @media (max-width:920px){.calc{grid-template-columns:1fr}}
  .panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow)}
  .panel h2{font-size:23px;margin-bottom:4px}
  .panel .sub{color:var(--ink-2);font-size:14.5px;margin:0 0 16px}
  fieldset{border:0;padding:0;margin:0 0 18px}
  legend{font-weight:700;font-size:14px;letter-spacing:.04em;text-transform:uppercase;color:var(--brand);padding:0;margin-bottom:10px}
  .field{margin-bottom:13px}
  .field label{display:block;font-weight:500;font-size:14.5px;margin-bottom:5px}
  .field .hint{font-size:13px;color:var(--ink-2);margin-top:4px}
  .field input,.field select{width:100%;padding:10px 12px;font:inherit;font-size:16px;border:1px solid var(--line);border-radius:9px;background:var(--bg);color:var(--ink)}
  .field input:focus,.field select:focus{outline:2px solid var(--brand);outline-offset:1px}
  .row2{display:grid;grid-template-columns:1fr 1fr;gap:12px}
  @media (max-width:480px){.row2{grid-template-columns:1fr}}
  .seg{display:flex;border:1px solid var(--line);border-radius:10px;overflow:hidden}
  .seg button{flex:1;padding:10px 6px;font:inherit;font-weight:600;font-size:14.5px;background:var(--surface-2);color:var(--ink-2);border:0;cursor:pointer}
  .seg button[aria-pressed="true"]{background:#2563EB;color:#fff}
  .results{position:sticky;top:86px}
  @media (max-width:920px){.results{position:static}}
  .big-result{background:linear-gradient(135deg,#2563EB,#1E40AF);color:#fff;border-radius:var(--radius);padding:22px;text-align:center}
  .big-result .lbl{font-size:13px;font-weight:700;letter-spacing:.07em;text-transform:uppercase;opacity:.85}
  .big-result .val{font-family:"Nunito","Inter",sans-serif;font-weight:800;font-size:46px;line-height:1.1;margin:4px 0}
  .big-result .note{font-size:13.5px;opacity:.9}
  .breakdown{margin-top:16px}
  .breakdown table{width:100%;border-collapse:collapse;font-size:15px}
  .breakdown td,.breakdown th{padding:8px 4px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
  .breakdown td:last-child,.breakdown th:last-child{text-align:right;font-variant-numeric:tabular-nums;white-space:nowrap}
  .breakdown tr.total td{font-weight:700;border-bottom:0}
  .warn{background:var(--sun-soft);border:1px solid var(--sun);color:var(--ink);border-radius:10px;padding:11px 14px;font-size:14px;margin-top:12px}
  /* prose */
  .prose{max-width:74ch}
  .prose h2{font-size:28px;margin:34px 0 10px}
  .prose h3{font-size:20px;margin:24px 0 8px}
  .prose p{margin:0 0 14px}
  .prose ul,.prose ol{margin:0 0 16px;padding-left:24px}
  .prose li{margin-bottom:7px}
  .prose table{width:100%;border-collapse:collapse;margin:14px 0 22px;font-size:15px;background:var(--surface)}
  .prose th,.prose td{border:1px solid var(--line);padding:9px 12px;text-align:left}
  .prose th{background:var(--surface-2)}
  .prose td:last-child,.prose th:last-child{text-align:right;font-variant-numeric:tabular-nums}
  .formula{background:var(--surface-2);border:1px solid var(--line);border-radius:10px;padding:14px 18px;font-size:17px;text-align:center;margin:16px 0;font-variant-numeric:tabular-nums}
  .callout{background:var(--brand-soft);border-radius:10px;padding:16px 18px;margin:18px 0}
  .callout p{margin:0}
  .disclaimer{font-size:13.5px;color:var(--ink-2);border-top:1px solid var(--line);margin-top:30px;padding-top:14px;max-width:74ch}
  details.faq{background:var(--surface);border:1px solid var(--line);border-radius:11px;padding:14px 18px;margin-bottom:10px}
  details.faq summary{font-weight:600;cursor:pointer}
  details.faq p{color:var(--ink-2);margin:10px 0 2px}
  /* states */
  .state-search{width:100%;padding:13px 16px;font:inherit;font-size:16.5px;border:1px solid var(--line);border-radius:11px;background:var(--surface);color:var(--ink);margin-bottom:18px}
  .state-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(215px,1fr));gap:10px}
  .state-link{display:flex;justify-content:space-between;align-items:center;background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:12px 15px;text-decoration:none;color:var(--ink);font-weight:500}
  .state-link:hover{border-color:var(--brand)}
  .state-link span{color:var(--brand)}
  .crumbs{font-size:14px;color:var(--ink-2);margin:22px 0 6px}
  .crumbs a{color:var(--ink-2)}
  .page-head{padding:26px 0 8px}
  .page-head h1{font-size:clamp(29px,4.6vw,42px);max-width:22ch}
  .page-head p.lede{font-size:18px;color:var(--ink-2);max-width:64ch;margin:12px 0 0}
  /* footer */
  footer.site{border-top:1px solid #1E293B;margin-top:50px;background:#0F172A;color:#E2E8F0}
  .foot{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:26px;padding:38px 0 26px}
  @media (max-width:820px){.foot{grid-template-columns:1fr 1fr}}
  @media (max-width:480px){.foot{grid-template-columns:1fr}}
  .foot h4{margin:0 0 12px;font-size:14px;letter-spacing:.05em;text-transform:uppercase;color:#FBBF24}
  .foot ul{list-style:none;margin:0;padding:0}
  .foot li{margin-bottom:8px}
  .foot a{color:#CBD5E1;text-decoration:none;font-size:15px}
  .foot a:hover{color:#FBBF24}
  .foot p{color:#CBD5E1;font-size:14.5px;max-width:36ch}
  .foot-base{border-top:1px solid #1E293B;padding:16px 0 22px;font-size:13.5px;color:#94A3B8;display:flex;flex-wrap:wrap;gap:8px 22px;justify-content:space-between}
    .sitemap-list{columns:2;column-gap:40px}
  @media (max-width:620px){.sitemap-list{columns:1}}
  .sitemap-list li{break-inside:avoid}

  /* ---------- Next.js port adaptations ----------
     The rules below keep the v3 pages' existing helper classes
     (.note, .good, .checklist, .steps, table.data, .toc, div.faq, .small)
     rendering in the same preview design language. */
  .small{font-size:13.5px;color:var(--ink-2)}
  p.lead{font-size:18px;color:var(--ink-2)}
  .note{background:var(--sun-soft);border:1px solid var(--sun);border-radius:10px;padding:14px 18px;margin:18px 0}
  .note p{margin:0}
  .good{background:var(--accent-soft);border-radius:10px;padding:16px 18px;margin:18px 0}
  .good p{margin:0}
  .prose .note,.prose .good{font-size:15.5px}
  .checklist{list-style:none;padding-left:0}
  .checklist li{padding-left:28px;position:relative}
  .checklist li::before{content:"✓";position:absolute;left:2px;color:var(--accent);font-weight:800}
  .steps{counter-reset:step;list-style:none;padding-left:0}
  .steps li{padding-left:44px;position:relative;min-height:30px}
  .steps li::before{counter-increment:step;content:counter(step);position:absolute;left:0;top:1px;background:#2563EB;color:#fff;width:29px;height:29px;border-radius:50%;text-align:center;line-height:29px;font-weight:700;font-size:14.5px}
  table.data{width:100%;border-collapse:collapse;margin:14px 0 22px;font-size:15px;background:var(--surface)}
  table.data th,table.data td{border:1px solid var(--line);padding:9px 12px;text-align:left}
  table.data th{background:var(--surface-2)}
  .toc{background:var(--surface-2);border:1px solid var(--line);border-radius:10px;padding:16px 18px;margin:18px 0}
  .toc b{display:block;margin-bottom:6px}
  div.faq{background:var(--surface);border:1px solid var(--line);border-radius:11px;padding:14px 18px;margin-bottom:10px}
  div.faq h3{font-size:16.5px;margin:0 0 6px}
  div.faq p{color:var(--ink-2);margin:0}
  .btn.alt{background:var(--surface);color:var(--ink);border:1px solid var(--line);box-shadow:none}
  .page-photo{width:100%;max-width:660px;border-radius:14px;margin:12px 0 6px;display:block}
  @media print{
    header.site,footer.site,.menu-btn,.print-hide{display:none}
  }