/* =========================================================================
   Variable Data PDF — "Serif Analytics" design system
   Warm paper ground, editorial serif headings, tabular monospaced numerals,
   forest + brass accents, financial-print-report energy.
   ========================================================================= */

:root {
  /* Palette */
  --paper: #f8f5ef;
  --paper-raised: #fffdf9;
  --paper-alt: #efe9db;
  --ink: #23261f;
  --ink-soft: #4a4d3f;
  --forest: #1e4d3b;
  --forest-dark: #16392b;
  --forest-deep: #123326;
  --brass: #a8853a;
  --brass-light: #c9a563;
  --brass-pale: #f1e6c9;
  --line: #d9d0b8;
  --line-strong: #b9ac86;
  --good: #1e4d3b;
  --danger: #7a3421;

  /* Type */
  --font-serif: Georgia, "Iowan Old Style", "Palatino Linotype", "Times New Roman", serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  /* Spacing / radii */
  --radius-sm: 3px;
  --radius-md: 6px;
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2.5rem;
  --space-5: 4rem;
  --content-max: 72rem;
  --measure: 42rem;
}

/* ---------- Reset ---------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: 17px;
  line-height: 1.6;
  background-image:
    linear-gradient(180deg, rgba(30,77,59,0.02), rgba(30,77,59,0) 240px);
}
img, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--forest); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--brass); }
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  color: var(--forest-deep);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.01em;
}
p { margin: 0 0 1em; }
ul, ol { padding-left: 1.3em; }
table { border-collapse: collapse; width: 100%; }
code, .num, .mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

:focus-visible {
  outline: 2px solid var(--brass);
  outline-offset: 2px;
  border-radius: 2px;
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

.wrap {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--space-3);
}

.visually-hidden {
  position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--forest);
  color: #fff;
  padding: 0.6em 1em;
  z-index: 100;
}
.skip-link:focus { left: var(--space-2); top: var(--space-2); }

/* ---------- Header / nav ---------------------------------------------- */
.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--paper-raised);
  position: sticky;
  top: 0;
  z-index: 40;
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem var(--space-3);
  max-width: var(--content-max);
  margin: 0 auto;
  gap: var(--space-2);
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.55em;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--forest-deep);
  text-decoration: none;
  white-space: nowrap;
}
.brand:hover { color: var(--forest-deep); }
.brand-mark { width: 30px; height: 30px; flex: none; }
.brand small {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.58rem;
  letter-spacing: 0.14em;
  color: var(--brass);
  font-weight: 600;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a:not(.btn) {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.95rem;
  border-bottom: 1px solid transparent;
}
.nav-links a:not(.btn):hover { color: var(--forest); border-bottom-color: var(--brass); }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 0.4em 0.6em;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--forest-deep);
}

/* ---------- Buttons ----------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 0.98rem;
  padding: 0.72em 1.35em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--forest-deep);
  background: var(--forest);
  color: #fdfbf5;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}
.btn:hover { background: var(--forest-deep); color: #fff; }
.btn:active { transform: translateY(1px); }
.btn-ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--forest-deep);
}
.btn-ghost:hover { background: var(--brass-pale); color: var(--forest-deep); border-color: var(--brass); }
.btn-block { width: 100%; justify-content: center; }

/* ---------- Hero -------------------------------------------------------- */
.hero {
  padding: var(--space-5) 0 var(--space-4);
  border-bottom: 1px solid var(--line);
}
.hero .wrap { display: grid; gap: var(--space-4); grid-template-columns: 1.15fr 0.85fr; align-items: center; }
.eyebrow {
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.72rem;
  color: var(--brass);
  font-weight: 700;
  margin: 0 0 0.9em;
}
.hero h1 { font-size: clamp(1.9rem, 4vw, 2.85rem); margin: 0 0 0.5em; }
.hero .subhead { font-size: 1.12rem; color: var(--ink-soft); max-width: 38em; margin-bottom: 1.4em; }
.hero-ctas { display: flex; gap: 0.9em; flex-wrap: wrap; align-items: center; margin-bottom: 1.1em; }
.trust-line {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--forest);
  display: flex;
  flex-wrap: wrap;
  gap: 0.4em 0.6em;
}
.trust-line span::after { content: "\2014"; margin-left: 0.6em; color: var(--line-strong); }
.trust-line span:last-child::after { content: ""; margin-left: 0; }

.hero-panel {
  background: var(--paper-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  box-shadow: 0 1px 0 var(--line);
}
.hero-panel .panel-title {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--brass);
  margin-bottom: 0.8em;
}
.ledger { width: 100%; border-collapse: collapse; font-family: var(--font-mono); font-size: 0.88rem; }
.ledger th { text-align: left; font-family: var(--font-serif); font-weight: 700; color: var(--forest-deep); border-bottom: 2px solid var(--forest); padding: 0.4em 0.5em; }
.ledger td { padding: 0.4em 0.5em; border-bottom: 1px dashed var(--line-strong); }
.ledger tr:last-child td { border-bottom: none; }
.ledger td.num { text-align: right; color: var(--forest-deep); }

/* ---------- Section shells ---------------------------------------------- */
section.block { padding: var(--space-5) 0; border-bottom: 1px solid var(--line); }
section.block:last-of-type { border-bottom: none; }
.section-head { max-width: 46rem; margin-bottom: var(--space-4); }
.section-head .eyebrow { margin-bottom: 0.6em; }
.section-head h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin: 0 0 0.4em; }
.section-head p { color: var(--ink-soft); margin: 0; }

/* ---------- How it works -------------------------------------------------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-3); counter-reset: step; }
.step { background: var(--paper-raised); border: 1px solid var(--line); border-radius: var(--radius-md); padding: var(--space-3); position: relative; }
.step .step-no {
  font-family: var(--font-mono); font-size: 0.75rem; color: var(--brass); font-weight: 700;
  letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 0.9em; display: block;
}
.step svg { width: 44px; height: 44px; margin-bottom: 0.9em; }
.step h3 { font-size: 1.08rem; margin: 0 0 0.4em; }
.step p { color: var(--ink-soft); font-size: 0.96rem; margin: 0; }

/* ---------- Feature grid -------------------------------------------------- */
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-3); }
.feature {
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: var(--radius-md);
  padding: var(--space-3);
}
.feature h3 { font-size: 1.03rem; margin: 0 0 0.4em; display: flex; align-items: center; gap: 0.5em; }
.feature h3 .tag { font-family: var(--font-mono); color: var(--brass); font-size: 0.85em; }
.feature p { color: var(--ink-soft); font-size: 0.94rem; margin: 0; }

/* ---------- Calculator ---------------------------------------------------- */
.calc {
  background: var(--paper-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  display: grid;
  gap: var(--space-3);
  grid-template-columns: 1fr 1fr;
}
.calc-form { display: grid; gap: 1em; align-content: start; }
.field { display: grid; gap: 0.35em; }
.field label { font-family: var(--font-mono); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--forest); font-weight: 700; }
.field input {
  font-family: var(--font-mono);
  font-size: 1rem;
  padding: 0.55em 0.7em;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: var(--paper);
  color: var(--ink);
}
.field input:focus { border-color: var(--brass); }
.field .hint { font-size: 0.8rem; color: var(--ink-soft); font-family: var(--font-serif); }
.calc-output {
  border-left: 1px dashed var(--line-strong);
  padding-left: var(--space-3);
  display: grid;
  align-content: start;
  gap: 0.9em;
}
.calc-output .panel-title { font-family: var(--font-mono); font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--brass); }
.calc-sequence { display: flex; flex-wrap: wrap; gap: 0.5em; align-items: center; font-family: var(--font-mono); font-size: 1.02rem; }
.chip {
  background: var(--brass-pale);
  border: 1px solid var(--brass-light);
  color: var(--forest-deep);
  border-radius: var(--radius-sm);
  padding: 0.3em 0.6em;
}
.ellipsis { color: var(--ink-soft); font-weight: 700; }
.calc-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 0.7em; }
.stat { border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 0.7em 0.8em; background: var(--paper); }
.stat .stat-label { font-family: var(--font-mono); font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--ink-soft); }
.stat .stat-value { font-family: var(--font-mono); font-size: 1.35rem; color: var(--forest-deep); font-weight: 700; }
.calc-warn { font-size: 0.85rem; color: var(--danger); font-family: var(--font-mono); display: none; }
.calc-warn.show { display: block; }

/* ---------- FAQ ------------------------------------------------------------ */
.faq-list { display: grid; gap: 0.7em; max-width: var(--measure); }
.faq-list details {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--paper-raised);
  padding: 0.2em 1em;
}
.faq-list summary {
  cursor: pointer;
  padding: 0.9em 0;
  font-weight: 700;
  font-family: var(--font-serif);
  color: var(--forest-deep);
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: 1em;
  align-items: center;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--brass);
  font-size: 1.3rem;
  flex: none;
}
.faq-list details[open] summary::after { content: "\2212"; }
.faq-list .faq-a { padding: 0 0 1em; color: var(--ink-soft); }
.faq-list .faq-a p:last-child { margin-bottom: 0; }

/* ---------- Blog cards ----------------------------------------------------- */
.blog-cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-3); }
.blog-card {
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  display: flex;
  flex-direction: column;
  gap: 0.6em;
  text-decoration: none;
  color: var(--ink);
}
.blog-card:hover { border-color: var(--brass); }
.blog-card .kicker { font-family: var(--font-mono); font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--brass); font-weight: 700; }
.blog-card h3 { margin: 0; font-size: 1.12rem; color: var(--forest-deep); }
.blog-card p { color: var(--ink-soft); font-size: 0.93rem; margin: 0; }
.blog-card .read-more { font-family: var(--font-mono); font-size: 0.85rem; color: var(--forest); margin-top: auto; }

/* ---------- Footer ----------------------------------------------------------- */
.site-footer { background: var(--forest-deep); color: #e9e4d4; padding: var(--space-4) 0 var(--space-3); }
.site-footer a { color: #f1ead2; }
.site-footer a:hover { color: var(--brass-light); }
.footer-grid { display: grid; grid-template-columns: 1.3fr 1fr 1fr 1fr; gap: var(--space-3); margin-bottom: var(--space-3); }
.footer-grid h4 { color: #cfead9; font-family: var(--font-mono); text-transform: uppercase; font-size: 0.72rem; letter-spacing: 0.12em; margin: 0 0 0.8em; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.5em; font-size: 0.92rem; }
.footer-brand p { color: #b9c9bd; font-size: 0.9rem; max-width: 26em; }
.footer-bottom {
  border-top: 1px solid rgba(233,228,212,0.18);
  padding-top: var(--space-2);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.6em;
  font-size: 0.82rem;
  color: #a9baae;
  font-family: var(--font-mono);
}

/* ---------- Article ----------------------------------------------------------- */
.article-header { padding: var(--space-4) 24px var(--space-2); border-bottom: 1px solid var(--line); }
.article-header .eyebrow { margin-bottom: 0.7em; }
.article-header h1 { font-size: clamp(1.7rem, 4vw, 2.5rem); margin: 0 0 0.5em; }
.byline { font-family: var(--font-mono); font-size: 0.83rem; color: var(--ink-soft); }
article.post { padding: var(--space-4) 24px; max-width: var(--measure); margin: 0 auto; }
article.post h2 { font-size: 1.5rem; margin: 1.8em 0 0.6em; }
article.post h3 { font-size: 1.18rem; margin: 1.4em 0 0.5em; }
article.post p { margin: 0 0 1.1em; }
article.post ul, article.post ol { margin: 0 0 1.1em; }
article.post li { margin-bottom: 0.4em; }

.answer-block {
  border: 1px solid var(--forest);
  border-left: 5px solid var(--brass);
  background: var(--paper-raised);
  padding: 1.3em 1.5em;
  border-radius: var(--radius-md);
  margin: 1.6em 0 2em;
}
.answer-block p { margin: 0; font-size: 1.04rem; color: var(--ink); }
.answer-block .answer-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--brass);
  margin-bottom: 0.6em;
  font-weight: 700;
}

figure.diagram {
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: var(--radius-md);
  padding: var(--space-2);
  margin: 1.8em 0;
}
figure.diagram svg { width: 100%; max-width: 560px; margin: 0 auto; display: block; }
figure.diagram figcaption {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--ink-soft);
  text-align: center;
  margin-top: 0.8em;
  border-top: 1px dashed var(--line-strong);
  padding-top: 0.6em;
}

.data-table-wrap { overflow-x: auto; margin: 1.6em 0; border: 1px solid var(--line); border-radius: var(--radius-md); }
table.data-table { font-size: 0.92rem; }
table.data-table caption {
  text-align: left; font-family: var(--font-mono); font-size: 0.72rem; text-transform: uppercase;
  letter-spacing: 0.1em; color: var(--brass); padding: 0.8em 1em 0.4em; font-weight: 700; background: var(--paper-raised);
}
table.data-table th, table.data-table td { padding: 0.6em 1em; text-align: left; border-bottom: 1px solid var(--line); }
table.data-table thead th { background: var(--forest); color: #fff; font-family: var(--font-serif); }
table.data-table tbody tr:nth-child(even) { background: var(--paper-alt); }
table.data-table td.num, table.data-table th.num { font-family: var(--font-mono); text-align: right; }

.callout {
  border-left: 4px solid var(--forest);
  background: var(--paper-alt);
  padding: 1em 1.2em;
  border-radius: var(--radius-sm);
  margin: 1.6em 0;
  font-size: 0.96rem;
}
.callout strong { color: var(--forest-deep); }

.footnote { font-size: 0.85rem; color: var(--ink-soft); border-top: 1px solid var(--line); margin-top: 2.2em; padding-top: 1em; }
.footnote a { word-break: break-word; }

.post-cta {
  margin: 2.5em 0;
  padding: var(--space-3);
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  flex-wrap: wrap;
}
.post-cta p { margin: 0; color: var(--ink-soft); max-width: 32em; }

/* ---------- Blog index ------------------------------------------------------ */
.blog-hero { padding: var(--space-4) 0 var(--space-3); border-bottom: 1px solid var(--line); }
.blog-index-list { display: grid; gap: var(--space-3); padding: var(--space-4) 0; }
.blog-index-card {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: var(--space-3);
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  text-decoration: none;
  color: var(--ink);
  align-items: start;
}
.blog-index-card:hover { border-color: var(--brass); }
.blog-index-card .index-no { font-family: var(--font-mono); color: var(--brass); font-size: 2.1rem; font-weight: 700; }
.blog-index-card h2 { margin: 0 0 0.4em; font-size: 1.25rem; color: var(--forest-deep); }
.blog-index-card p { margin: 0; color: var(--ink-soft); }
.blog-index-card .meta { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-soft); margin-top: 0.6em; display: block; }

/* ---------- 404 -------------------------------------------------------------- */
.error-page { padding: var(--space-5) 0; text-align: center; }
.error-page .code { font-family: var(--font-mono); font-size: 4rem; color: var(--brass); font-weight: 700; }
.error-page h1 { margin: 0.2em 0 0.4em; }
.error-page .error-actions { display: flex; gap: 1em; justify-content: center; margin-top: 1.6em; flex-wrap: wrap; }

/* ---------- Responsive -------------------------------------------------------- */
@media (max-width: 900px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .steps, .features { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .calc { grid-template-columns: 1fr; }
  .calc-output { border-left: none; padding-left: 0; border-top: 1px dashed var(--line-strong); padding-top: var(--space-3); }
  .blog-cards { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--paper-raised);
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-2) var(--space-3);
    gap: var(--space-2);
  }
  .nav-toggle { display: inline-block; }
  .steps, .features { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .blog-index-card { grid-template-columns: 1fr; }
  .blog-index-card .index-no { font-size: 1.4rem; }
  .calc-stats { grid-template-columns: 1fr; }
  section.block { padding: var(--space-4) 0; }
}