:root {
  --paper: #FBFAF6;
  --ink: #1C1F1A;
  --ledger: #1E5C45;
  --copy: #A63D2F;
  --cash: #2E6B4F;
  --line: #D8D5C9;
  --tint: #F2F0E7;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --serif: "Libre Baskerville", Georgia, "Times New Roman", serif;
  --body: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.65;
}

.container { max-width: 860px; margin: 0 auto; padding: 0 20px; }

/* header: printed-form double rule */
.site-head {
  border-bottom: 3px solid var(--ink);
  padding: 18px 0 14px;
  margin-bottom: 28px;
}
.site-head .container {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.brand {
  font-family: var(--serif);
  font-size: 19px;
  letter-spacing: 1px;
  color: var(--ink);
  text-decoration: none;
}
.brand .stamp {
  color: var(--copy);
  font-family: var(--mono);
  font-size: 10px;
  border: 1.5px solid var(--copy);
  padding: 1px 6px;
  margin-left: 6px;
  letter-spacing: 1px;
  vertical-align: 2px;
}
.nav a {
  color: var(--ledger);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  margin-left: 16px;
}
.nav a:hover { text-decoration: underline; }

.hero { padding: 12px 0 28px; }
.kicker {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--copy);
  margin-bottom: 10px;
}
h1, h2, h3 { font-family: var(--serif); font-weight: 700; line-height: 1.25; }
h1 { font-size: 34px; max-width: 640px; margin-bottom: 14px; }
h2 { font-size: 24px; margin: 34px 0 12px; }
h3 { font-size: 18px; margin: 18px 0 8px; }
.lede { font-size: 17px; max-width: 640px; color: #3c3f38; }

.bluf {
  border-left: 4px solid var(--ledger);
  background: var(--tint);
  padding: 14px 18px;
  margin: 18px 0;
  font-size: 15.5px;
}

.cta {
  margin: 22px 0 8px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
}
.btn {
  display: inline-block;
  padding: 12px 22px;
  background: var(--copy);
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  border-radius: 2px;
  border: 1px solid var(--copy);
  font-size: 15px;
}
.btn:hover { filter: brightness(0.95); }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn:focus-visible { outline: 3px solid var(--ledger); outline-offset: 2px; }

.meta-note {
  font-family: var(--mono);
  font-size: 12px;
  color: #6b6f66;
  margin-top: 8px;
}

/* invoice preview card (signature) */
.invoice-preview {
  border-top: 4px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  background: #fff;
  padding: 20px 24px;
  margin: 20px 0 8px;
  font-size: 13.5px;
  max-width: 560px;
}
.inv-head-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  border-bottom: 2px solid var(--ink);
  padding-bottom: 8px;
  margin-bottom: 12px;
}
.inv-head-row strong { font-family: var(--serif); font-size: 20px; letter-spacing: 4px; }
.inv-head-row span { font-family: var(--mono); font-size: 11px; color: var(--ledger); }
.inv-party { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-bottom: 10px; }
.inv-party .lbl { font-family: var(--mono); font-size: 9.5px; text-transform: uppercase; letter-spacing: 1px; color: var(--copy); }
.inv-rows { border-top: 1px solid var(--line); }
.inv-row {
  display: grid;
  grid-template-columns: 1fr 60px 80px 90px;
  gap: 8px;
  padding: 6px 0;
  border-bottom: 1px solid var(--line);
  font-variant-numeric: tabular-nums;
}
.inv-row .n { text-align: right; }
.inv-total {
  display: flex;
  justify-content: flex-end;
  gap: 30px;
  margin-top: 10px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

/* data table */
.data-table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 14.5px; }
.data-table th {
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  text-align: left;
  color: var(--ledger);
  border-bottom: 2px solid var(--ink);
  padding: 8px 10px;
}
.data-table td { padding: 8px 10px; border-bottom: 1px solid var(--line); }
.data-table td.num, .data-table th.num { text-align: right; font-variant-numeric: tabular-nums; }

/* feature grid */
.feats { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 14px; margin: 16px 0; }
.feat {
  border: 1px solid var(--line);
  border-top: 3px solid var(--ledger);
  background: #fff;
  padding: 14px 16px;
  border-radius: 2px;
}
.feat h3 { font-size: 15.5px; margin: 0 0 6px; }
.feat p { font-size: 13.5px; color: #3c3f38; }

/* faq */
.faq details {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 2px;
  margin-bottom: 8px;
}
.faq summary {
  cursor: pointer;
  padding: 12px 16px;
  font-weight: 600;
  font-size: 15px;
}
.faq summary:hover { color: var(--ledger); }
.faq details p { padding: 0 16px 14px; font-size: 14px; color: #3c3f38; }
.faq summary:focus-visible { outline: 3px solid var(--ledger); outline-offset: -2px; }

/* related cards */
.rel { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 12px; margin: 16px 0; }
.rel a.card {
  display: block;
  border: 1px solid var(--line);
  background: #fff;
  padding: 12px 14px;
  text-decoration: none;
  color: var(--ink);
  border-radius: 2px;
  font-size: 14px;
  font-weight: 600;
}
.rel a.card:hover { border-color: var(--ledger); color: var(--ledger); }

/* sections & footer */
section { margin-bottom: 26px; }
.site-foot {
  border-top: 3px solid var(--ink);
  margin-top: 40px;
  padding: 18px 0 26px;
  font-size: 13px;
  color: #6b6f66;
}
.site-foot a { color: var(--ledger); }
.site-foot .mono { font-family: var(--mono); font-size: 11px; }

.step-note {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--copy);
  background: var(--tint);
  padding: 8px 12px;
  border-radius: 2px;
  margin: 10px 0;
}

@media (max-width: 640px) {
  h1 { font-size: 27px; }
  .inv-row { grid-template-columns: 1fr 44px 64px 72px; font-size: 12px; }
  .nav a { margin-left: 10px; font-size: 13px; }
}