:root {
  color-scheme: light;
  --canvas: #f3f1ea;
  --surface: #fbfaf6;
  --ink: #1d2927;
  --muted: #60706c;
  --line: rgba(29, 41, 39, 0.14);
  --accent: #1d6b5b;
  --accent-soft: #dce9e3;
  --warm: #a65136;
  --radius: 12px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--canvas);
  color: var(--ink);
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

a:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--warm);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: 6px;
  background: var(--ink);
  color: white;
  transform: translateY(-180%);
}

.skip-link:focus {
  transform: translateY(0);
}

.document-shell {
  display: grid;
  grid-template-columns: 268px minmax(0, 1fr);
  max-width: 1320px;
  min-height: 100vh;
  margin: 0 auto;
}

.document-sidebar {
  position: sticky;
  top: 0;
  align-self: start;
  min-width: 0;
  height: 100vh;
  padding: 36px 30px;
  border-right: 1px solid var(--line);
}

.document-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 50%;
  background: var(--ink);
  color: var(--canvas);
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.document-identity {
  display: grid;
  gap: 3px;
  padding: 20px 0 26px;
  border-bottom: 1px solid var(--line);
}

.eyebrow,
.document-title,
.document-version,
.sidebar-note,
.section-number {
  margin: 0;
}

.eyebrow,
.section-number {
  color: var(--accent);
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.document-title {
  font-size: 18px;
  font-weight: 650;
}

.document-version,
.sidebar-note {
  color: var(--muted);
  font-size: 13px;
}

.document-sidebar nav {
  display: grid;
  gap: 2px;
  padding: 22px 0;
}

.document-sidebar nav a {
  padding: 7px 9px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.document-sidebar nav a:hover {
  background: rgba(29, 107, 91, 0.08);
  color: var(--ink);
}

.sidebar-note {
  max-width: 24ch;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

main {
  min-width: 0;
  padding: 72px clamp(30px, 6vw, 88px) 120px;
}

main > * {
  max-width: 900px;
  margin-right: auto;
  margin-left: auto;
}

.plan-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 250px;
  gap: 58px;
  padding-bottom: 54px;
  border-bottom: 1px solid var(--line);
}

h1,
h2,
h3,
p {
  text-wrap: pretty;
}

h1,
h2,
h3 {
  margin-top: 0;
  font-weight: 650;
  letter-spacing: -0.025em;
  line-height: 1.16;
  text-wrap: balance;
}

h1 {
  max-width: 19ch;
  margin-bottom: 24px;
  font-size: clamp(42px, 6vw, 70px);
}

h2 {
  font-size: clamp(27px, 3vw, 36px);
}

h3 {
  font-size: 18px;
}

.lede {
  max-width: 63ch;
  margin: 0;
  color: var(--muted);
  font-size: 19px;
  line-height: 1.65;
}

.plan-meta {
  display: grid;
  align-content: start;
  gap: 0;
  margin: 4px 0 0;
}

.plan-meta div {
  padding: 13px 0;
  border-top: 1px solid var(--line);
}

.plan-meta div:last-child {
  border-bottom: 1px solid var(--line);
}

dt {
  color: var(--ink);
  font-weight: 650;
}

dd {
  margin: 2px 0 0;
  color: var(--muted);
}

.plan-meta dt {
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.plan-meta dd {
  font-size: 14px;
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 650;
}

.status::before {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: currentColor;
  content: "";
}

.status-high {
  background: #f0d8d0;
  color: #7b311f;
}

.status-medium {
  background: #eee2bb;
  color: #685418;
}

.status-low {
  background: var(--accent-soft);
  color: #175749;
}

.decision-callout {
  margin-top: 44px;
  padding: 30px;
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--accent-soft);
}

.decision-callout h2 {
  max-width: 30ch;
  margin: 10px 0 14px;
  font-size: clamp(25px, 3vw, 34px);
}

.decision-callout > p:last-child {
  max-width: 70ch;
  margin: 0;
}

.success-section {
  padding: 72px 0 24px;
}

.success-section > h2 {
  max-width: 26ch;
  margin-bottom: 32px;
}

.success-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 0;
}

.success-grid div {
  min-width: 0;
  padding: 0 18px;
  border-left: 1px solid var(--line);
}

.success-grid div:first-child {
  padding-left: 0;
  border-left: 0;
}

.success-grid div:last-child {
  padding-right: 0;
}

.success-grid dt {
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 23px;
  font-variant-numeric: tabular-nums;
}

.success-grid dd {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.5;
}

main > section[id] {
  padding-top: 94px;
}

.section-heading {
  display: flex;
  align-items: flex-start;
  gap: 22px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}

.section-number {
  flex: 0 0 auto;
  padding-top: 8px;
}

.section-heading h2 {
  margin-bottom: 8px;
}

.section-heading p:last-child {
  max-width: 56ch;
  margin: 0;
  color: var(--muted);
}

.two-column,
.scope-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 46px;
  padding-top: 34px;
}

.two-column p {
  margin-bottom: 0;
  color: var(--muted);
}

.scope-grid > div {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(251, 250, 246, 0.6);
}

.scope-grid h3 {
  margin-bottom: 18px;
}

ul,
ol {
  padding-left: 1.25rem;
}

.scope-grid ul {
  display: grid;
  gap: 10px;
  margin: 0;
}

.scope-grid li::marker {
  color: var(--accent);
}

.constraints {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px;
  margin: 34px 0 0;
}

.constraints div {
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.constraints dd {
  margin-top: 7px;
  font-size: 14px;
}

.architecture-map {
  margin: 34px 0 0;
  padding: 28px;
  border-radius: var(--radius);
  background: var(--ink);
  color: white;
}

.architecture-map figcaption {
  max-width: 66ch;
  margin-bottom: 24px;
  color: rgba(255, 255, 255, 0.68);
  font-size: 14px;
}

.architecture-flow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: flow;
}

.architecture-flow li {
  position: relative;
  display: flex;
  min-width: 0;
  flex-direction: column;
  gap: 7px;
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 9px;
  background: rgba(255, 255, 255, 0.06);
  counter-increment: flow;
}

.architecture-flow li:not(:last-child)::after {
  position: absolute;
  top: 50%;
  right: -13px;
  z-index: 2;
  color: #87c6b7;
  content: "→";
  font-weight: 700;
  transform: translateY(-50%);
}

.architecture-flow .device-boundary {
  border-style: dashed;
}

.architecture-flow strong {
  font-size: 16px;
}

.architecture-flow span:last-child {
  color: rgba(255, 255, 255, 0.68);
  font-size: 13px;
  line-height: 1.5;
}

.node-label {
  color: #87c6b7;
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.architecture-notes {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 38px;
  padding-top: 26px;
}

.architecture-notes article {
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.architecture-notes h3,
.architecture-notes p {
  margin-bottom: 0;
}

.architecture-notes p {
  color: var(--muted);
}

.table-scroll {
  margin-top: 30px;
  overflow-x: auto;
}

table {
  width: 100%;
  min-width: 760px;
  border-collapse: collapse;
  font-size: 14px;
}

caption {
  padding-bottom: 12px;
  color: var(--muted);
  font-size: 14px;
  text-align: left;
}

th,
td {
  padding: 16px 14px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  text-align: left;
}

th {
  font-weight: 650;
}

thead th {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.03em;
  white-space: nowrap;
}

tbody th {
  width: 17%;
}

.decision-log {
  display: grid;
  gap: 0;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.decision-log li {
  display: grid;
  grid-template-columns: 132px 220px minmax(0, 1fr);
  gap: 24px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}

.decision-log h3,
.decision-log dl {
  margin: 0;
}

.decision-log dl {
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  gap: 5px 12px;
  color: var(--muted);
}

.decision-log dt {
  color: var(--ink);
  font-weight: 650;
}

.decision-log dd {
  margin: 0;
}

.decision-id {
  color: var(--accent);
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  font-weight: 700;
}

.question-list {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.question-list > li {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 190px;
  gap: 30px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}

.question-list h3,
.question-list p,
.question-list dl {
  margin: 0;
}

.question-list p {
  margin-top: 7px;
  color: var(--muted);
}

.question-list dl {
  display: grid;
  grid-template-columns: auto 1fr;
  align-content: start;
  gap: 3px 12px;
  font-size: 13px;
}

.question-list dd {
  margin: 0;
}

.review-checklist {
  display: grid;
  gap: 12px;
  margin: 30px 0 0;
}

.review-checklist li::marker {
  color: var(--accent);
}

.plan-footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.8fr);
  gap: 54px;
  margin-top: 112px;
  padding: 38px;
  border-radius: var(--radius);
  background: var(--accent-soft);
}

.plan-footer h2 {
  max-width: 24ch;
  margin: 10px 0 0;
  font-size: 28px;
}

.plan-footer ul {
  display: grid;
  gap: 9px;
  margin: 0;
}

@media (max-width: 1040px) {
  .document-shell {
    grid-template-columns: 220px minmax(0, 1fr);
  }

  .document-sidebar {
    padding: 28px 20px;
  }

  main {
    padding-right: 40px;
    padding-left: 40px;
  }

  .plan-header {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .plan-meta {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .plan-meta div:nth-child(odd) {
    padding-right: 20px;
  }

  .plan-meta div:nth-child(even) {
    padding-left: 20px;
  }

  .architecture-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .architecture-flow li::after {
    display: none;
  }

  .decision-log li {
    grid-template-columns: 110px 180px minmax(0, 1fr);
  }
}

@media (max-width: 760px) {
  html {
    scroll-padding-top: 148px;
  }

  .document-shell {
    display: block;
  }

  .document-sidebar {
    position: sticky;
    top: 0;
    z-index: 10;
    display: grid;
    height: auto;
    padding: 12px 18px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    background: rgba(243, 241, 234, 0.96);
    backdrop-filter: blur(12px);
  }

  .document-mark,
  .document-version,
  .sidebar-note {
    display: none;
  }

  .document-identity {
    padding: 0;
    border: 0;
  }

  .document-title {
    font-size: 16px;
  }

  .document-sidebar nav {
    display: flex;
    gap: 4px;
    margin: 7px -18px 0;
    padding: 7px 18px 10px;
    overflow-x: auto;
    scrollbar-width: thin;
  }

  .document-sidebar nav a {
    flex: 0 0 auto;
    min-height: 44px;
    padding: 10px 12px;
    font-size: 15px;
  }

  main {
    padding: 50px 20px 86px;
  }

  h1 {
    font-size: 43px;
  }

  .lede {
    font-size: 18px;
  }

  .success-grid,
  .constraints {
    grid-template-columns: 1fr;
  }

  .success-grid div,
  .success-grid div:first-child,
  .success-grid div:last-child {
    padding: 16px 0;
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .success-grid div:last-child {
    border-bottom: 1px solid var(--line);
  }

  .success-grid dd,
  .constraints dd,
  .architecture-map figcaption,
  .architecture-flow span:last-child,
  .plan-meta dd {
    font-size: 16px;
  }

  main > section[id] {
    padding-top: 76px;
  }

  .two-column,
  .scope-grid,
  .architecture-notes,
  .architecture-flow,
  .plan-footer {
    grid-template-columns: 1fr;
  }

  .two-column,
  .scope-grid {
    gap: 24px;
  }

  .decision-log li {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .question-list > li {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .plan-footer {
    gap: 28px;
    padding: 26px;
  }
}

@media print {
  body {
    background: white;
    color: black;
    font-size: 11pt;
  }

  .document-shell {
    display: block;
    max-width: none;
  }

  .document-sidebar,
  .skip-link,
  script {
    display: none;
  }

  main {
    padding: 0;
  }

  main > section[id] {
    break-inside: avoid;
    padding-top: 42px;
  }

  .plan-header {
    grid-template-columns: 1fr 220px;
  }

  .architecture-map {
    border: 1px solid #333;
    background: white;
    color: black;
  }

  .architecture-map figcaption,
  .architecture-flow span:last-child {
    color: #444;
  }

  .architecture-flow li {
    border-color: #888;
    background: white;
  }

  .node-label,
  .architecture-flow li:not(:last-child)::after {
    color: #333;
  }
}

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