:root {
    --ink: #1a2b2b;
    --ink-soft: #2f4344;
    --muted: #6b7a7a;
    --line: #d8d3c8;
    --paper: #f7f4ec;
    --paper-warm: #efe9dc;
    --accent: #385c56;
    --accent-dark: #2b4741;
    --serif: "Georgia", "Iowan Old Style", "Palatino Linotype", serif;
    --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  }

  * { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body {
    margin: 0;
    font-family: var(--sans);
    color: var(--ink);
    background: var(--paper);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
  }
  a { color: var(--accent-dark); text-decoration: underline; text-underline-offset: 3px; }
  a:hover { color: var(--ink); }
  h1, h2, h3 { font-family: var(--serif); font-weight: 500; color: var(--ink); letter-spacing: -0.01em; }
  h1 { font-size: 2.6rem; line-height: 1.15; margin: 0 0 1rem; }
  h2 { font-size: 1.9rem; line-height: 1.2; margin: 0 0 1rem; }
  h3 { font-size: 1.25rem; margin: 0 0 0.5rem; }
  p { margin: 0 0 1rem; max-width: 62ch; }

  .container { max-width: 1040px; margin: 0 auto; padding: 0 1.5rem; }

  /* Nav */
  header.site-nav {
    padding: 1.25rem 0;
    border-bottom: 1px solid var(--line);
    background: var(--paper);
    position: sticky; top: 0; z-index: 10;
  }
  .nav-inner { display: flex; justify-content: space-between; align-items: center; }
  .brand {
    font-family: var(--serif);
    font-size: 1.15rem;
    font-weight: 500;
    color: var(--ink);
    text-decoration: none;
    letter-spacing: 0.02em;
  }
  .brand span { color: var(--accent); }
  nav ul { list-style: none; display: flex; gap: 1.75rem; margin: 0; padding: 0; }
  nav a { text-decoration: none; color: var(--ink-soft); font-size: 0.95rem; }
  nav a:hover { color: var(--accent-dark); }

  /* Hero */
  section.hero {
    padding: 5rem 0 4rem;
    border-bottom: 1px solid var(--line);
  }
  .hero-eyebrow {
    text-transform: uppercase;
    letter-spacing: 0.14em;
    font-size: 0.78rem;
    color: var(--accent);
    margin-bottom: 1rem;
    font-weight: 600;
  }
  .hero p.lede {
    font-size: 1.2rem;
    color: var(--ink-soft);
    max-width: 55ch;
  }
  .cta-row {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 2rem;
  }
  .btn {
    display: inline-block;
    padding: 0.85rem 1.5rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    border: 1px solid transparent;
    transition: background 0.15s, color 0.15s, border 0.15s;
  }
  .btn-primary {
    background: var(--accent-dark);
    color: var(--paper);
  }
  .btn-primary:hover { background: var(--ink); color: var(--paper); }
  .btn-secondary {
    background: transparent;
    color: var(--accent-dark);
    border-color: var(--accent-dark);
  }
  .btn-secondary:hover { background: var(--accent-dark); color: var(--paper); }

  /* Sections */
  section.block {
    padding: 4.5rem 0;
    border-bottom: 1px solid var(--line);
  }
  section.block:last-of-type { border-bottom: none; }
  .section-eyebrow {
    text-transform: uppercase;
    letter-spacing: 0.14em;
    font-size: 0.78rem;
    color: var(--accent);
    font-weight: 600;
    margin-bottom: 0.75rem;
  }

  /* Criteria grid */
  .criteria-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.75rem;
    margin-top: 2rem;
  }
  .criteria-card {
    background: var(--paper-warm);
    padding: 1.5rem;
    border-left: 3px solid var(--accent);
  }
  .criteria-card h3 { color: var(--accent-dark); }
  .criteria-card p { font-size: 0.95rem; color: var(--ink-soft); margin: 0; }

  /* FAQ */
  .faq details {
    border-bottom: 1px solid var(--line);
    padding: 1.25rem 0;
  }
  .faq details summary {
    cursor: pointer;
    font-family: var(--serif);
    font-size: 1.15rem;
    color: var(--ink);
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
  }
  .faq details summary::-webkit-details-marker { display: none; }
  .faq details summary::after {
    content: "+";
    color: var(--accent);
    font-size: 1.4rem;
    font-weight: 300;
    flex-shrink: 0;
  }
  .faq details[open] summary::after { content: "\2013"; }
  .faq details p {
    margin: 0.75rem 0 0;
    color: var(--ink-soft);
  }

  /* About / Contact two-column */
  .two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
  }
  @media (max-width: 720px) {
    .two-col { grid-template-columns: 1fr; gap: 2rem; }
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    section.hero { padding: 3rem 0; }
    section.block { padding: 3rem 0; }
    nav ul { gap: 1rem; }
  }

  /* Contact form */
  form.contact {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1.5rem;
  }
  form.contact label {
    font-size: 0.85rem;
    color: var(--ink-soft);
    font-weight: 600;
    display: block;
    margin-bottom: 0.35rem;
  }
  form.contact input,
  form.contact textarea,
  form.contact select {
    width: 100%;
    padding: 0.7rem 0.85rem;
    border: 1px solid var(--line);
    background: #fff;
    font-family: var(--sans);
    font-size: 1rem;
    color: var(--ink);
    border-radius: 3px;
  }
  form.contact textarea { min-height: 120px; resize: vertical; }
  form.contact button {
    background: var(--accent-dark);
    color: var(--paper);
    border: none;
    padding: 0.9rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 4px;
    align-self: flex-start;
  }
  form.contact button:hover { background: var(--ink); }

  .contact-direct {
    background: var(--paper-warm);
    padding: 1.75rem;
    border-left: 3px solid var(--accent);
  }
  .contact-direct h3 { color: var(--accent-dark); margin-bottom: 1rem; }
  .contact-direct p { font-size: 0.98rem; margin-bottom: 0.75rem; }

  /* Footer */
  footer.site-foot {
    padding: 2rem 0;
    border-top: 1px solid var(--line);
    font-size: 0.85rem;
    color: var(--muted);
    background: var(--paper-warm);
  }
  footer.site-foot .foot-inner {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
  }
  footer.site-foot a { color: var(--muted); }

  /* ---- Article / interior pages ---- */
  .crumbs { font-size: 0.85rem; color: var(--muted); padding: 1.5rem 0 0; }
  .crumbs a { color: var(--muted); }
  article.prose { padding: 2.5rem 0 1rem; }
  article.prose h2 { margin-top: 3rem; }
  article.prose h3 { margin-top: 2rem; font-size: 1.1rem; }
  article.prose ul, article.prose ol { max-width: 62ch; padding-left: 1.25rem; }
  article.prose li { margin-bottom: 0.6rem; }
  .callout {
    border-left: 3px solid var(--accent);
    background: var(--paper-warm);
    padding: 1.25rem 1.5rem;
    margin: 2rem 0;
    max-width: 62ch;
  }
  .callout p:last-child { margin-bottom: 0; }
  ul.key-points {
    list-style: none;
    padding: 0;
    margin: 1.5rem 0 2rem;
    max-width: 62ch;
    display: grid;
    gap: 0.6rem;
  }
  ul.key-points li {
    position: relative;
    padding: 0.7rem 1rem 0.7rem 2.1rem;
    background: var(--paper-warm);
    border-radius: 3px;
    font-size: 0.97rem;
    margin-bottom: 0;
  }
  ul.key-points li::before {
    content: "\\2713";
    position: absolute;
    left: 0.85rem;
    top: 0.72rem;
    color: var(--accent);
    font-weight: 700;
  }
  .page-cta {
    border-top: 1px solid var(--line);
    margin-top: 3.5rem;
    padding: 2.5rem 0 1rem;
  }
  .related { border-top: 1px solid var(--line); padding: 2rem 0 0; margin-top: 2.5rem; }
  .related ul { list-style: none; padding: 0; margin: 0.75rem 0 0; }
  .related li { margin-bottom: 0.5rem; }
  table.plain { border-collapse: collapse; margin: 1.5rem 0; font-size: 0.95rem; width: 100%; max-width: 62ch; }
  table.plain th, table.plain td { text-align: left; padding: 0.6rem 0.9rem; border-bottom: 1px solid var(--line); vertical-align: top; }
  table.plain th { font-family: var(--serif); font-weight: 500; }
  @media (max-width: 640px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    nav ul { gap: 1rem; flex-wrap: wrap; }
  }

  /* ---- Diagrams ---- */
  figure.diagram { margin: 2.5rem 0; max-width: 760px; }
  figure.diagram img {
    display: block; width: 100%; height: auto;
    border: 1px solid var(--line); border-radius: 3px; background: var(--paper);
  }
  figure.diagram figcaption {
    margin-top: 0.75rem; font-size: 0.88rem; color: var(--muted);
    font-style: italic; max-width: 62ch;
  }