:root {
  --paper: #f3f0f7;
  --surface: #fffefe;
  --surface-soft: #ebe5f3;
  --ink: #261f31;
  --muted: #655d6e;
  --line: #d3c9df;
  --line-strong: #9a8baa;
  --accent: #6732c8;
  --accent-dark: #4c1f9e;
  --signal: #b86bff;
  --night: #26183f;
  --implemented: #2e6654;
  --experimental: #7c5b18;
  --proposed: #596574;
  --historical: #6d6161;
  --shell: min(1160px, calc(100% - 2.5rem));
  --reading: 760px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  min-width: 320px;
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 1rem;
  line-height: 1.65;
}
a { color: inherit; text-decoration-color: var(--line-strong); text-underline-offset: .2em; }
a:hover { color: var(--accent-dark); text-decoration-color: currentColor; }
.shell { width: var(--shell); margin-inline: auto; }
.skip-link {
  position: fixed;
  z-index: 20;
  top: 1rem;
  left: 1rem;
  padding: .7rem 1rem;
  transform: translateY(-180%);
  background: var(--night);
  color: white;
}
.skip-link:focus { transform: none; }

.status-bar {
  background: var(--night);
  color: #f3f1eb;
  font-size: .74rem;
  font-weight: 750;
  letter-spacing: .08em;
  text-align: center;
  text-transform: uppercase;
}
.status-bar .shell { padding-block: .5rem; }
.site-header { border-bottom: 1px solid var(--line); background: rgba(255, 255, 255, .9); }
.site-header__inner { display: flex; align-items: center; justify-content: space-between; gap: 2rem; min-height: 92px; }
.brand { display: flex; align-items: center; gap: .85rem; text-decoration: none; }
.brand__words { display: grid; line-height: 1.2; }
.brand__words strong { font-size: .98rem; }
.brand__words small { margin-top: .2rem; color: var(--muted); font-size: .72rem; }
.primary-nav { display: flex; flex-wrap: wrap; gap: 1.25rem; font-size: .88rem; font-weight: 700; }
.primary-nav a { text-decoration: none; }

.page-hero { border-bottom: 1px solid var(--line); background: var(--surface); }
.page-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(220px, .65fr);
  align-items: center;
  gap: clamp(2rem, 8vw, 7rem);
  min-height: 560px;
  padding-block: clamp(4.5rem, 9vw, 8rem);
}
.page-hero__visual { display: grid; place-items: center; min-height: 300px; background: var(--surface-soft); }
.page-hero h1,
.not-found h1 {
  max-width: 980px;
  margin: 0 0 1.4rem;
  font-family: inherit;
  font-size: clamp(3rem, 7vw, 6.4rem);
  font-weight: 300;
  letter-spacing: -.035em;
  line-height: 1;
  text-wrap: balance;
}
.page-hero__summary { max-width: 820px; margin: 0; color: var(--muted); font-size: clamp(1.15rem, 2.2vw, 1.45rem); }
.page-hero__meta { display: flex; align-items: center; gap: 1rem; margin-top: 2rem; color: var(--muted); font-size: .82rem; }
.kicker {
  margin: 0 0 .75rem;
  color: var(--accent-dark);
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.maturity {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  padding: .28rem .58rem;
  border: 1px solid currentColor;
  border-radius: 999px;
  color: var(--proposed);
  font-size: .68rem;
  font-weight: 800;
  letter-spacing: .04em;
  line-height: 1.1;
  text-transform: uppercase;
  white-space: nowrap;
}
.maturity--implemented { color: var(--implemented); }
.maturity--experimental { color: var(--experimental); }
.maturity--in-development { color: #725127; }
.maturity--historical,
.maturity--superseded { color: var(--historical); }

.section-heading { max-width: 780px; margin-bottom: 2rem; }
.section-heading h2,
.diagram__header h2,
.prose h2 {
  margin: 0;
  font-family: inherit;
  font-size: clamp(2rem, 4vw, 3.35rem);
  font-weight: 300;
  letter-spacing: -.025em;
  line-height: 1.08;
  text-wrap: balance;
}
.route-section { padding-block: clamp(4rem, 8vw, 6.5rem); }
.route-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.route-card,
.relationship-card,
.evidence-card { border: 1px solid var(--line); background: var(--surface); }
.route-card { min-height: 245px; padding: 1.5rem; }
.route-card__top,
.relationship-card__heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; }
.route-card__top > span { color: var(--muted); font-size: .72rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.route-card h3,
.relationship-card h3,
.evidence-card h3,
.page-furniture__context h3,
.diagram-node h3 { margin: 1.4rem 0 .65rem; font-size: 1.14rem; line-height: 1.25; }
.route-card p,
.relationship-card p,
.diagram-node p { margin-bottom: 0; color: var(--muted); }
.route-card h3 a::after { content: " →"; color: var(--signal); }

.diagram-shell { padding-bottom: clamp(4rem, 8vw, 6.5rem); }
.route-section + .diagram-shell { padding-top: 0; }
.page-hero + .diagram-shell { padding-top: clamp(4rem, 8vw, 6.5rem); }
.diagram { margin: 0; padding: clamp(1.4rem, 4vw, 2.5rem); border: 1px solid var(--line-strong); background: var(--surface-soft); }
.diagram__header { max-width: 820px; margin-bottom: 2rem; }
.diagram__header p:last-child { color: var(--muted); }
.diagram__nodes { display: grid; margin: 0; padding: 0; list-style: none; }
.diagram__nodes--map { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .85rem; }
.diagram__nodes--flow { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.8rem .85rem; }
.diagram__nodes--loop { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .85rem; }
.diagram-node {
  position: relative;
  display: flex;
  gap: .85rem;
  min-height: 180px;
  padding: 1.15rem;
  border: 1px solid var(--line);
  background: var(--surface);
}
.diagram__nodes--flow .diagram-node:not(:last-child)::after {
  content: "→";
  position: absolute;
  z-index: 2;
  top: 50%;
  right: -.95rem;
  color: var(--signal);
  font-size: 1.2rem;
  transform: translate(50%, -50%);
}
.diagram__nodes--flow .diagram-node:nth-child(3n)::after { content: "↓"; top: auto; right: 50%; bottom: -1.55rem; transform: translate(50%, 50%); }
.diagram__nodes--loop .diagram-node--outer { grid-column: 1 / -1; min-height: auto; border: 2px solid var(--signal); }
.diagram-node__number { color: var(--signal); font-family: ui-monospace, "SFMono-Regular", Consolas, monospace; font-size: .76rem; font-weight: 800; }
.diagram-node h3 { margin-top: 0; }
.diagram-node .maturity { margin-top: .8rem; }
.diagram__connections { margin-top: 1.25rem; padding: 1rem; border-top: 1px solid var(--line); }
.diagram__connections summary { cursor: pointer; font-weight: 750; }
.diagram__connections ul { margin-bottom: 0; }
.diagram figcaption { margin-top: 1.3rem; color: var(--muted); font-size: .86rem; }

.content-shell { padding-bottom: clamp(4rem, 8vw, 7rem); }
.prose { max-width: var(--reading); }
.prose h2 { margin: 3.5rem 0 1.1rem; font-size: clamp(1.8rem, 3.4vw, 2.65rem); }
.prose h2:first-child { margin-top: 0; }
.prose p,
.prose li { color: #39434b; }
.prose p { margin: 0 0 1.15rem; }
.prose li + li { margin-top: .5rem; }
.prose strong { color: var(--ink); }

.page-furniture,
.relationships { padding-block: clamp(4rem, 8vw, 6.5rem); border-top: 1px solid var(--line); }
.page-furniture__grid { display: grid; grid-template-columns: minmax(230px, .7fr) minmax(0, 1.8fr); gap: 2rem; }
.page-furniture__context { display: grid; align-content: start; gap: 1.4rem; }
.page-furniture__context > div { padding-bottom: 1.4rem; border-bottom: 1px solid var(--line); }
.page-furniture__context h3 { margin-top: 0; }
.page-furniture__context p,
.page-furniture__context li { color: var(--muted); font-size: .9rem; }
.page-furniture__context ul,
.evidence-card ul { padding-left: 1.15rem; }
.evidence-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.evidence-card { padding: 1.3rem; border-top-width: 3px; }
.evidence-card--implemented { border-top-color: var(--implemented); }
.evidence-card--proposed { border-top-color: var(--proposed); }
.evidence-card--limitations { border-top-color: var(--historical); }
.evidence-card--next { border-top-color: var(--signal); }
.evidence-card h3 { margin-top: 0; }
.evidence-card li { color: var(--muted); font-size: .92rem; }
.evidence-card li + li { margin-top: .55rem; }

.relationship-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.relationship-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; margin: 0; padding: 0; list-style: none; }
.relationship-list li { padding: 1.35rem; border: 1px solid var(--line); background: var(--surface); }
.relationship-card { padding: 1.35rem; }
.relationship-card h3 { margin-top: 0; }
.related-sites { padding-block: clamp(4rem, 8vw, 7rem); background: var(--night); color: #f5f3ee; }
.related-sites .kicker { color: #c9b796; }
.related-sites .relationship-card { border-color: #536069; background: #27323a; }
.related-sites .relationship-card p { color: #cbd1d4; }
.related-sites a:hover { color: white; }
.related-sites .maturity { color: #d8d1c3; }

.site-footer { padding-block: 2.5rem; border-top: 1px solid var(--line); background: var(--surface); color: var(--muted); font-size: .84rem; }
.site-footer__grid { display: grid; grid-template-columns: 1.4fr .6fr; gap: 2rem; }
.site-footer__statement { margin-top: 0; color: var(--ink); font-size: 1rem; font-weight: 750; }
.site-footer nav { display: flex; flex-direction: column; align-items: flex-start; gap: .55rem; }

.brand-mark { position: relative; display: inline-block; flex: 0 0 auto; width: 54px; height: 54px; color: var(--accent-dark); }
.brand-mark--hero { width: 180px; height: 180px; }
.brand-mark--ap { border: 7px solid currentColor; border-right-color: transparent; border-radius: 50%; transform: rotate(-25deg); }
.brand-mark--ap::before,
.brand-mark--ap::after { content: ""; position: absolute; border: 4px solid currentColor; border-radius: 50%; }
.brand-mark--ap::before { inset: 8px; border-left-color: transparent; transform: rotate(80deg); }
.brand-mark--ap::after { inset: 19px; border-bottom-color: transparent; transform: rotate(30deg); }
.brand-mark--hero.brand-mark--ap { border-width: 16px; }
.brand-mark--hero.brand-mark--ap::before { inset: 29px; border-width: 12px; }
.brand-mark--hero.brand-mark--ap::after { inset: 67px; border-width: 9px; }

/* Approved Route A Open BPM mark: work items move around a complete cycle. */
.brand-mark--bpm {
  --bpm-mark-scale: 1;
  width: calc(76px * var(--bpm-mark-scale));
  height: calc(76px * var(--bpm-mark-scale));
  border: calc(7px * var(--bpm-mark-scale)) solid #6c36d9;
  border-radius: 50%;
  transform: rotate(20deg);
}
.brand-mark--bpm i {
  position: absolute;
  display: block;
  width: calc(29px * var(--bpm-mark-scale));
  height: calc(16px * var(--bpm-mark-scale));
  border: calc(2px * var(--bpm-mark-scale)) solid #18222c;
  background: #e5ad45;
  transform: rotate(-20deg);
}
.brand-mark--bpm i:nth-child(1) { top: calc(-4px * var(--bpm-mark-scale)); left: calc(19px * var(--bpm-mark-scale)); background: #63e7df; }
.brand-mark--bpm i:nth-child(2) { top: calc(25px * var(--bpm-mark-scale)); right: calc(-10px * var(--bpm-mark-scale)); background: #f2ea64; }
.brand-mark--bpm i:nth-child(3) { bottom: calc(-3px * var(--bpm-mark-scale)); left: calc(19px * var(--bpm-mark-scale)); background: #7bd500; }
.brand-mark--bpm i:nth-child(4) { top: calc(25px * var(--bpm-mark-scale)); left: calc(-10px * var(--bpm-mark-scale)); background: #f2f14c; }
.brand-mark--hero.brand-mark--bpm { --bpm-mark-scale: 2.368421; }

.brand-mark--domain { display: grid; place-items: center; border-left: 7px solid currentColor; border-right: 7px solid currentColor; }
.brand-mark--domain::before { content: "•  •"; letter-spacing: .16rem; }
.brand-mark--domain::after { content: ""; position: absolute; top: 10px; left: 12px; right: 12px; height: 3px; background: var(--signal); box-shadow: 0 15px 0 #4f9991, 0 30px 0 #c76758; }
.brand-mark--hero.brand-mark--domain { border-width: 18px; }
.brand-mark--hero.brand-mark--domain::before { font-size: 2rem; letter-spacing: 1rem; }
.brand-mark--hero.brand-mark--domain::after { top: 28px; left: 34px; right: 34px; height: 10px; box-shadow: 0 49px 0 #4f9991, 0 98px 0 #c76758; }

.brand-mark--core { display: grid; place-items: center; border: 2px solid currentColor; transform: rotate(45deg); }
.brand-mark--core::before { content: ""; width: 31px; height: 31px; border: 5px solid currentColor; }
.brand-mark--core::after { content: ""; position: absolute; width: 12px; height: 12px; background: var(--signal); }
.brand-mark--hero.brand-mark--core { border-width: 7px; }
.brand-mark--hero.brand-mark--core::before { width: 112px; height: 112px; border-width: 14px; }
.brand-mark--hero.brand-mark--core::after { width: 42px; height: 42px; }
.not-found { min-height: 62vh; padding-block: clamp(5rem, 12vw, 9rem); }
.not-found p { max-width: 680px; color: var(--muted); }
.button { display: inline-flex; margin-top: 1rem; padding: .7rem 1rem; border: 1px solid var(--ink); background: var(--ink); color: white; font-weight: 750; text-decoration: none; }
.button:hover { background: var(--accent-dark); color: white; }

.prose pre { overflow-x: auto; padding: 1.35rem; border: 1px solid var(--line); background: var(--night); color: #f7f3ea; }
.prose code { font-family: ui-monospace, "SFMono-Regular", Consolas, monospace; font-size: .9em; }

@media (max-width: 880px) {
  .site-header__inner { align-items: flex-start; flex-direction: column; gap: 1rem; padding-block: 1rem; }
  .page-hero__grid { grid-template-columns: 1fr; min-height: auto; }
  .page-hero__visual { min-height: 250px; }
  .route-grid,
  .diagram__nodes--map,
  .diagram__nodes--flow,
  .diagram__nodes--loop { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .diagram__nodes--flow .diagram-node:nth-child(3n)::after { content: "→"; top: 50%; right: -.95rem; bottom: auto; transform: translate(50%, -50%); }
  .diagram__nodes--flow .diagram-node:nth-child(2n)::after { content: "↓"; top: auto; right: 50%; bottom: -1.55rem; transform: translate(50%, 50%); }
}

@media (max-width: 680px) {
  :root { --shell: min(100% - 1.4rem, 1160px); }
  .primary-nav { gap: .7rem 1rem; }
  .page-hero__grid { padding-block: 4rem; }
  .page-hero__visual { min-height: 220px; }
  .brand-mark--hero { transform: scale(.75); }
  .brand-mark--hero.brand-mark--bpm { transform: rotate(20deg) scale(.75); }
  .page-hero h1,
  .not-found h1 { font-size: clamp(2.65rem, 14vw, 4.2rem); }
  .page-hero__meta { align-items: flex-start; flex-direction: column; gap: .6rem; }
  .route-grid,
  .diagram__nodes--map,
  .diagram__nodes--flow,
  .diagram__nodes--loop,
  .page-furniture__grid,
  .evidence-grid,
  .relationship-grid,
  .relationship-list,
  .site-footer__grid { grid-template-columns: 1fr; }
  .route-card { min-height: auto; }
  .diagram-node { min-height: auto; }
  .diagram__nodes--loop .diagram-node--outer { grid-column: auto; }
  .diagram__nodes--flow .diagram-node:not(:last-child)::after,
  .diagram__nodes--flow .diagram-node:nth-child(2n)::after,
  .diagram__nodes--flow .diagram-node:nth-child(3n)::after {
    content: "↓";
    top: auto;
    right: 50%;
    bottom: -1.55rem;
    transform: translate(50%, 50%);
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}