/* BillJean — ledger-paper system
   8px base grid · 12 columns · mirrored double-entry layouts */

:root {
  --navy: #0b2150;
  --navy-2: #13306b;
  --blue: #0a7cf0;
  --blue-soft: #e3f0ff;
  --mark: #f3e24a;          /* highlighter, hue 57° */
  --mark-soft: #fbf5bf;
  --paper: #f7f6f1;
  --paper-2: #efede5;
  --card: #ffffff;
  --ink: #0b2150;
  --ink-2: #44506b;
  --ink-3: #7a8399;
  --rule: #dcd9cd;
  --rule-soft: #e9e6dc;
  --ok: #138a52;
  --due: #b45309;

  --font: "Plus Jakarta Sans", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --u: 8px;
  --max: 1152px;
  --radius: 16px;
  --shadow: 0 1px 0 rgba(11, 33, 80, .04), 0 24px 48px -24px rgba(11, 33, 80, .22);
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* faint ledger grid: 8 × 8 cells, every 8th line slightly stronger */
.ledger-bg {
  background-image:
    linear-gradient(var(--rule-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--rule-soft) 1px, transparent 1px);
  background-size: 64px 64px;
  background-position: -1px -1px;
}

img, svg { display: block; max-width: 100%; }
a { color: var(--blue); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--navy); }

:focus-visible { outline: 3px solid var(--blue); outline-offset: 3px; border-radius: 4px; }

.skip {
  position: absolute; left: -9999px; top: 8px;
  background: var(--navy); color: #fff; padding: 8px 16px; border-radius: 8px; z-index: 99;
}
.skip:focus { left: 16px; }

.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* ---------- Wordmark ---------- */
.wordmark {
  display: inline-flex; align-items: baseline;
  font-weight: 800; letter-spacing: -0.045em; line-height: 1;
  font-size: 28px; text-decoration: none;
}
.wordmark .b { color: var(--navy); }
.wordmark .j { color: var(--blue); }
.wordmark:hover .b { color: var(--navy); }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--rule);
}
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 72px; gap: 16px; }
.nav { display: flex; gap: 4px; align-items: center; }
.nav a {
  color: var(--ink-2); text-decoration: none; font-weight: 600; font-size: 15px;
  padding: 8px 12px; border-radius: 8px;
}
.nav a:hover, .nav a[aria-current="page"] { color: var(--navy); background: var(--paper-2); }
.nav .btn { margin-left: 8px; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font: inherit; font-weight: 700; font-size: 15px; line-height: 1;
  padding: 14px 20px; border-radius: 999px; border: 1.5px solid transparent;
  text-decoration: none; cursor: pointer; transition: transform .15s ease, background .15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--navy); color: #fff; }
.btn-primary:hover { background: var(--navy-2); color: #fff; }
.btn-ghost { background: transparent; color: var(--navy); border-color: var(--navy); }
.btn-ghost:hover { background: var(--card); color: var(--navy); }
.nav .btn { padding: 10px 16px; }
.nav .btn-primary, .nav .btn-primary:hover { color: #fff; background: var(--navy); }

/* ---------- Type ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 13px; font-weight: 500; letter-spacing: .04em; text-transform: uppercase;
  color: var(--ink-2);
}
.eyebrow::before { content: ""; width: 8px; height: 8px; border-radius: 2px; background: var(--blue); }

h1, h2, h3 { color: var(--navy); letter-spacing: -0.035em; line-height: 1.05; margin: 0; }
h1 { font-size: clamp(44px, 6.4vw, 80px); font-weight: 800; }
h2 { font-size: clamp(32px, 4vw, 48px); font-weight: 800; }
h3 { font-size: 20px; font-weight: 750; letter-spacing: -0.02em; line-height: 1.25; }

.lede { font-size: clamp(18px, 1.6vw, 20px); color: var(--ink-2); max-width: 34em; }

.hl {
  background: linear-gradient(transparent 58%, var(--mark) 58%, var(--mark) 92%, transparent 92%);
  padding: 0 .06em; margin: 0 -.06em;
  -webkit-box-decoration-break: clone; box-decoration-break: clone;
}
.blue { color: var(--blue); }

/* ---------- Hero ---------- */
.hero { padding: 96px 0 104px; border-bottom: 1px solid var(--rule); }
.hero .wrap { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 32px; align-items: center; }
.hero-copy { grid-column: span 7; }
.hero-copy h1 { margin: 24px 0 24px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 40px; }
.hero-art { grid-column: span 5; display: flex; justify-content: center; }

/* receipt card */
.receipt {
  position: relative; width: 100%; max-width: 400px;
  background: var(--card); border-radius: 16px 16px 0 0;
  box-shadow: var(--shadow);
  padding: 24px 24px 32px;
  font-family: var(--mono); font-size: 13px; color: var(--ink-2);
  transform: rotate(1.2deg);
}
.receipt::after {
  /* perforated bottom edge */
  content: ""; position: absolute; left: 0; right: 0; bottom: -12px; height: 12px;
  background:
    radial-gradient(circle at 8px 0, var(--card) 8px, transparent 8.5px) 0 0 / 16px 12px repeat-x;
  filter: drop-shadow(0 6px 6px rgba(11,33,80,.08));
}
.r-head { display: flex; justify-content: space-between; align-items: center; padding-bottom: 16px; border-bottom: 1.5px dashed var(--rule); }
.r-head .wordmark { font-size: 20px; font-family: var(--font); }
.r-deal { padding: 16px 0; border-bottom: 1.5px dashed var(--rule); }
.r-deal b { display: block; color: var(--navy); font-family: var(--font); font-size: 17px; font-weight: 750; letter-spacing: -0.01em; }
.r-rows { list-style: none; margin: 0; padding: 8px 0; border-bottom: 1.5px dashed var(--rule); }
.r-rows li { display: grid; grid-template-columns: 1fr auto; gap: 4px 16px; padding: 10px 0; }
.r-rows .id { color: var(--navy); font-weight: 600; }
.r-rows .amt { color: var(--navy); font-weight: 600; text-align: right; font-variant-numeric: tabular-nums; }
.r-rows .src { font-size: 12px; color: var(--ink-3); }
.pill { justify-self: end; font-size: 11px; font-weight: 600; letter-spacing: .04em; text-transform: uppercase; padding: 2px 8px; border-radius: 999px; }
.pill.paid { color: var(--ok); background: #e3f5ec; }
.pill.open { color: var(--due); background: #fdf0dc; }
.pill.draft { color: var(--ink-2); background: var(--paper-2); }
.r-total { display: flex; justify-content: space-between; padding-top: 16px; color: var(--navy); font-weight: 700; font-size: 15px; }
.r-total span:last-child { background: var(--mark); padding: 0 6px; border-radius: 3px; }
.stamp {
  position: absolute; right: -16px; top: 112px;
  font-family: var(--font); font-weight: 800; font-size: 13px; letter-spacing: .12em; text-transform: uppercase;
  color: var(--blue); border: 2.5px solid var(--blue); border-radius: 8px; padding: 6px 12px;
  transform: rotate(-11deg); background: rgba(255,255,255,.85);
}

/* ---------- Sections ---------- */
section { scroll-margin-top: 88px; }
.section { padding: 112px 0; border-bottom: 1px solid var(--rule); }
.section-head { max-width: 720px; margin-bottom: 64px; }
.section-head h2 { margin: 16px 0 16px; }
.section-head p { color: var(--ink-2); margin: 0; font-size: 18px; }

/* mirrored double-entry */
.mirror { display: grid; grid-template-columns: 1fr 96px 1fr; align-items: stretch; }
.side { background: var(--card); border: 1px solid var(--rule); border-radius: var(--radius); padding: 32px; }
.side h3 { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }
.side .tag { font-family: var(--mono); font-size: 12px; color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; }
.side ul { list-style: none; padding: 0; margin: 24px 0 0; }
.side li { display: flex; justify-content: space-between; gap: 16px; padding: 12px 0; border-top: 1px solid var(--rule-soft); font-size: 15px; color: var(--ink-2); }
.side li span:last-child { font-family: var(--mono); font-size: 13px; color: var(--navy); }
.side.right { background: var(--navy); border-color: var(--navy); color: #c9d4ee; }
.side.right h3 { color: #fff; }
.side.right .tag { color: #8fa3cf; }
.side.right li { border-top-color: rgba(255,255,255,.12); color: #c9d4ee; }
.side.right li span:last-child { color: var(--mark); }
.hinge { position: relative; display: flex; align-items: center; justify-content: center; }
.hinge::before { content: ""; position: absolute; top: 24px; bottom: 24px; left: 50%; border-left: 2px dashed var(--rule); }
.hinge-dot {
  position: relative; width: 56px; height: 56px; border-radius: 50%;
  background: var(--mark); color: var(--navy);
  display: grid; place-items: center; font-weight: 800; font-size: 20px;
  box-shadow: 0 0 0 8px var(--paper);
}

/* capability grid — 12 cols */
.grid-12 { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 24px; }
.cap { grid-column: span 4; padding: 32px; background: var(--card); border: 1px solid var(--rule); border-radius: var(--radius); }
.cap .n { font-family: var(--mono); font-size: 13px; color: var(--blue); font-weight: 600; }
.cap h3 { margin: 16px 0 8px; }
.cap p { margin: 0; color: var(--ink-2); font-size: 16px; }

/* marketplaces table */
.ledger-table { width: 100%; border-collapse: collapse; background: var(--card); border: 1px solid var(--rule); border-radius: var(--radius); overflow: hidden; }
.ledger-table th, .ledger-table td { text-align: left; padding: 20px 24px; border-bottom: 1px solid var(--rule-soft); vertical-align: middle; }
.ledger-table tr:last-child td { border-bottom: 0; }
.ledger-table th { font-family: var(--mono); font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-3); background: var(--paper-2); }
.ledger-table td:first-child { font-weight: 700; color: var(--navy); }
.ledger-table td.num { font-family: var(--mono); color: var(--ink-3); font-size: 13px; width: 64px; }
.status { display: inline-flex; align-items: center; gap: 8px; font-family: var(--mono); font-size: 13px; color: var(--ink-2); white-space: nowrap; }
.status::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--ink-3); }
.status.build::before { background: var(--blue); box-shadow: 0 0 0 4px var(--blue-soft); }
.status.plan::before { background: transparent; border: 1.5px solid var(--ink-3); }

/* principles */
.principles { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 0 48px; }
.principles li { padding: 24px 0; border-top: 1px solid var(--rule); display: grid; grid-template-columns: 40px 1fr; gap: 8px; }
.principles .k { font-family: var(--mono); font-size: 13px; color: var(--ink-3); padding-top: 3px; }
.principles b { color: var(--navy); display: block; margin-bottom: 4px; }
.principles p { margin: 0; color: var(--ink-2); font-size: 16px; }

/* contact band */
.band { padding: 112px 0; background: var(--navy); color: #c9d4ee; }
.band .wrap { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 32px; align-items: end; }
.band h2 { color: #fff; grid-column: span 7; }
.band .band-copy { grid-column: span 5; }
.band .eyebrow { color: #8fa3cf; }
.band .eyebrow::before { background: var(--mark); }
.band p { margin: 0 0 24px; }
.band .btn-primary { background: var(--mark); color: var(--navy); }
.band .btn-primary:hover { background: #fff; color: var(--navy); }
.band a.mail { color: #fff; }

/* ---------- Footer ---------- */
.site-footer { padding: 64px 0 48px; font-size: 15px; color: var(--ink-2); }
.foot-grid { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 32px; }
.foot-brand { grid-column: span 5; }
.foot-brand p { margin: 16px 0 0; max-width: 28em; }
.foot-col { grid-column: span 2; }
.foot-col.wide { grid-column: span 3; }
.foot-col h4 { margin: 0 0 16px; font-family: var(--mono); font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-3); }
.foot-col ul { list-style: none; margin: 0; padding: 0; }
.foot-col li { margin: 0 0 8px; }
.foot-col a { color: var(--ink-2); text-decoration: none; }
.foot-col a:hover { color: var(--navy); text-decoration: underline; }
.foot-col address { font-style: normal; }
.foot-base { margin-top: 56px; padding-top: 24px; border-top: 1px solid var(--rule); display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px; font-size: 13px; color: var(--ink-3); }
.foot-base p { margin: 0; }

/* ---------- Legal / doc pages ---------- */
.doc-hero { padding: 80px 0 48px; border-bottom: 1px solid var(--rule); }
.doc-hero h1 { font-size: clamp(40px, 5vw, 64px); margin: 16px 0 16px; }
.doc-hero .meta { font-family: var(--mono); font-size: 13px; color: var(--ink-3); }
.doc { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 32px; padding: 64px 0 112px; }
.toc { grid-column: span 3; position: sticky; top: 104px; align-self: start; font-size: 14px; }
.toc h4 { margin: 0 0 12px; font-family: var(--mono); font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-3); }
.toc ol { margin: 0; padding: 0; list-style: none; counter-reset: t; }
.toc li { counter-increment: t; margin: 0; }
.toc a { display: block; padding: 6px 0 6px 12px; border-left: 2px solid var(--rule); color: var(--ink-2); text-decoration: none; }
.toc a::before { content: counter(t, decimal-leading-zero) "  "; font-family: var(--mono); font-size: 12px; color: var(--ink-3); white-space: pre; }
.toc a:hover { color: var(--navy); border-left-color: var(--blue); }
.prose { grid-column: 5 / span 8; max-width: 720px; }
.prose h2 { font-size: 28px; margin: 56px 0 16px; letter-spacing: -0.025em; scroll-margin-top: 96px; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 18px; margin: 32px 0 8px; }
.prose p, .prose li { color: var(--ink-2); }
.prose strong { color: var(--navy); }
.prose ul { padding-left: 20px; }
.prose li { margin-bottom: 8px; }
.prose li::marker { color: var(--blue); }
.callout { background: var(--mark-soft); border-left: 4px solid var(--mark); padding: 20px 24px; border-radius: 0 12px 12px 0; margin: 24px 0; color: var(--navy); }
.callout p { margin: 0; color: var(--navy); }
.addr-card { background: var(--card); border: 1px solid var(--rule); border-radius: 12px; padding: 24px; font-style: normal; color: var(--navy); line-height: 1.7; }

/* support cards */
.support-grid { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 24px; padding: 64px 0 32px; }
.support-grid .cap { grid-column: span 4; }
.support-grid .cap a { font-weight: 700; }
.faq { padding: 32px 0 112px; max-width: 800px; }
.faq details { border-top: 1px solid var(--rule); padding: 20px 0; }
.faq details:last-child { border-bottom: 1px solid var(--rule); }
.faq summary { cursor: pointer; font-weight: 700; color: var(--navy); list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: var(--mono); color: var(--blue); font-size: 20px; line-height: 1; }
.faq details[open] summary::after { content: "−"; }
.faq details p { color: var(--ink-2); margin: 12px 0 0; }

/* 404 */
.nf { min-height: 64vh; display: grid; place-items: center; text-align: center; padding: 96px 0; }
.nf .code { font-family: var(--mono); font-size: 14px; color: var(--ink-3); }
.nf h1 { margin: 16px 0; }
.nf p { color: var(--ink-2); margin: 0 0 32px; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero .wrap, .band .wrap, .foot-grid, .doc, .grid-12, .support-grid { gap: 16px; }
  .hero { padding: 64px 0 80px; }
  .hero-copy, .hero-art { grid-column: 1 / -1; }
  .hero-art { margin-top: 24px; }
  .cap { grid-column: span 6; }
  .band h2, .band .band-copy { grid-column: 1 / -1; }
  .foot-brand { grid-column: 1 / -1; }
  .foot-col, .foot-col.wide { grid-column: span 4; }
  .toc { display: none; }
  .prose { grid-column: 1 / -1; }
  .support-grid .cap { grid-column: 1 / -1; }
}
@media (max-width: 720px) {
  body { font-size: 16px; }
  .hero .wrap, .band .wrap, .foot-grid, .doc, .grid-12, .support-grid { grid-template-columns: minmax(0, 1fr); gap: 24px; }
  .hero-copy, .hero-art, .band h2, .band .band-copy, .foot-brand, .foot-col, .foot-col.wide, .prose, .cap, .support-grid .cap { grid-column: 1 / -1; }
  .wrap { padding: 0 16px; }
  .nav a:not(.btn) { display: none; }
  .section, .band { padding: 80px 0; }
  .section-head { margin-bottom: 40px; }
  .mirror { grid-template-columns: 1fr; }
  .hinge { height: 88px; }
  .hinge::before { top: 0; bottom: 0; }
  .side { padding: 24px; }
  .cap { grid-column: 1 / -1; padding: 24px; }
  .principles { grid-template-columns: 1fr; }
  .foot-col, .foot-col.wide { grid-column: 1 / -1; }
  .ledger-table th:nth-child(3), .ledger-table td:nth-child(3) { display: none; }
  .ledger-table th, .ledger-table td { padding: 16px; }
  .receipt { transform: none; }
  .stamp { right: 8px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn { transition: none; }
}