:root {
  color-scheme: light;
  --paper: #f7f8f5;
  --white: #ffffff;
  --ink: #171a1f;
  --muted: #5f6670;
  --line: #d9ded8;
  --line-strong: #aab3aa;
  --red: #b63b2f;
  --teal: #08766d;
  --blue: #245b91;
  --gold: #b47a16;
  --violet: #7053a3;
  --green: #4f7d3f;
  --orange: #bd5d22;
  --shadow: 0 24px 60px rgba(23, 26, 31, 0.12);
  --radius: 8px;
  --max: 1180px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--paper);
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(23, 26, 31, 0.045) 1px, transparent 1px),
    linear-gradient(180deg, rgba(23, 26, 31, 0.035) 1px, transparent 1px),
    var(--paper);
  background-size: 32px 32px;
  line-height: 1.55;
}

a {
  color: inherit;
  text-decoration-color: rgba(8, 118, 109, 0.45);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

a:hover { text-decoration-color: currentColor; }

img { max-width: 100%; display: block; }

code, pre {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

pre {
  margin: 0;
  padding: 1rem;
  overflow: auto;
  color: #eef4ed;
  background: #171a1f;
  border-radius: var(--radius);
  font-size: 0.88rem;
  line-height: 1.55;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: 1rem;
  transform: translateY(-160%);
  padding: 0.7rem 0.9rem;
  background: var(--ink);
  color: var(--white);
  border-radius: var(--radius);
  z-index: 20;
}

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

:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
}

.shell {
  width: min(var(--max), calc(100% - 2rem));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(247, 248, 245, 0.94);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  min-width: max-content;
}

.brand-mark {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  color: var(--white);
  background: var(--ink);
  border-radius: 6px;
  font-weight: 850;
  letter-spacing: 0;
}

.brand strong,
.brand small {
  display: block;
  line-height: 1.1;
}

.brand small {
  margin-top: 0.18rem;
  color: var(--muted);
  font-size: 0.78rem;
}

.primary-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 0.25rem;
}

.nav-link,
.layer-chip,
.button {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  border-radius: 6px;
  transition: background-color 160ms ease, color 160ms ease, border-color 160ms ease, transform 160ms ease;
}

.nav-link {
  padding: 0.45rem 0.7rem;
  color: #303640;
  font-size: 0.9rem;
}

.nav-link:hover,
.nav-link.is-active {
  background: var(--ink);
  color: var(--white);
}

.layer-rail {
  border-top: 1px solid var(--line);
  overflow-x: auto;
}

.layer-strip {
  display: flex;
  gap: 0.35rem;
  padding-block: 0.5rem;
}

.layer-chip {
  flex: 0 0 auto;
  gap: 0.4rem;
  padding: 0.38rem 0.58rem 0.38rem 0.42rem;
  border: 1px solid var(--line);
  background: var(--white);
  font-size: 0.85rem;
  color: #303640;
}

.layer-chip span {
  width: 24px;
  height: 24px;
  display: grid;
  place-items: center;
  border-radius: 4px;
  color: var(--white);
  background: var(--ink);
  font-size: 0.78rem;
  font-weight: 800;
}

.layer-chip:hover,
.layer-chip.is-active {
  border-color: var(--ink);
  transform: translateY(-1px);
}

.band {
  padding: 5rem 0;
}

.band-white {
  background: rgba(255, 255, 255, 0.76);
  border-block: 1px solid var(--line);
}

.band-ink {
  color: var(--white);
  background:
    linear-gradient(120deg, rgba(8, 118, 109, 0.18), transparent 34%),
    linear-gradient(240deg, rgba(180, 122, 22, 0.18), transparent 35%),
    var(--ink);
}

.hero {
  min-height: 620px;
  display: grid;
  align-items: center;
}

.hero-grid,
.split,
.two-col,
.chart-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: clamp(1.5rem, 4vw, 4rem);
  align-items: center;
}

.hero-grid > *,
.split > *,
.two-col > *,
.chart-grid > * {
  min-width: 0;
}

.hero-small {
  padding: 4.5rem 0 3.5rem;
}

.hero-small .shell {
  max-width: 880px;
  margin-left: max(1rem, calc((100vw - var(--max)) / 2));
}

.eyebrow {
  margin: 0 0 0.8rem;
  color: var(--teal);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.band-ink .eyebrow { color: #8fe1d7; }

h1, h2, h3, p {
  margin-top: 0;
}

h1 {
  margin-bottom: 1rem;
  max-width: 12ch;
  font-size: clamp(3.3rem, 9vw, 7.5rem);
  line-height: 0.92;
  letter-spacing: 0;
  overflow-wrap: normal;
  word-break: normal;
}

.hero-title {
  max-width: none;
}

.hero-title span {
  display: block;
  width: fit-content;
  max-width: 100%;
}

.hero-small h1,
.layer-hero h1 {
  max-width: 15ch;
  font-size: clamp(2.8rem, 7vw, 5.8rem);
}

h2 {
  margin-bottom: 0.75rem;
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 1.02;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 0.55rem;
  font-size: 1.25rem;
  line-height: 1.2;
}

.lede {
  max-width: 68ch;
  color: #303640;
  font-size: clamp(1.1rem, 2vw, 1.35rem);
}

.band-ink .lede,
.band-ink p { color: rgba(255, 255, 255, 0.78); }

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

.button {
  min-width: 11rem;
  padding: 0.8rem 1rem;
  border: 1px solid var(--ink);
  font-weight: 800;
}

.button:hover { transform: translateY(-1px); }

.button-primary {
  color: var(--white);
  background: var(--ink);
}

.button-secondary {
  color: var(--ink);
  background: var(--white);
}

.route-panel {
  padding: clamp(1rem, 2vw, 1.5rem);
  background: var(--white);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.route-line {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
}

.route-line strong {
  color: var(--ink);
  text-align: right;
}

.route-stack {
  display: grid;
  gap: 0.55rem;
  margin-top: 1rem;
}

.route-stack span {
  display: block;
  padding: 0.85rem;
  color: var(--white);
  background: var(--ink);
  border-left: 8px solid var(--teal);
  border-radius: 6px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.95rem;
}

.route-stack span:nth-child(1) { border-color: var(--red); }
.route-stack span:nth-child(2) { border-color: var(--teal); }
.route-stack span:nth-child(3) { border-color: var(--blue); }
.route-stack span:nth-child(4) { border-color: var(--gold); }
.route-stack span:nth-child(5) { border-color: var(--violet); }
.route-stack span:nth-child(6) { border-color: var(--green); }
.route-stack span:nth-child(7) { border-color: var(--orange); }

.section-heading {
  max-width: 780px;
  margin-bottom: 2rem;
}

.section-heading p {
  color: var(--muted);
  font-size: 1.08rem;
}

.layer-grid,
.gap-grid,
.check-grid,
.step-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.layer-grid {
  grid-template-columns: repeat(7, minmax(160px, 1fr));
  overflow-x: auto;
  padding-bottom: 0.5rem;
}

.layer-card,
.gap-grid article,
.check-grid article,
.step-grid article,
.example,
.template-panel,
.layer-summary,
.callout,
.diagram {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.layer-card {
  min-height: 250px;
  border-top-width: 6px;
}

.layer-card-link {
  min-height: 100%;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  padding: 1rem;
  text-decoration: none;
}

.layer-card h3 {
  font-size: 1.35rem;
}

.layer-card p {
  color: var(--muted);
  font-size: 0.95rem;
}

.layer-card code,
.spec-table code {
  padding: 0.12rem 0.28rem;
  background: #eef1ed;
  border: 1px solid var(--line);
  border-radius: 4px;
  color: #293037;
  white-space: nowrap;
}

.layer-card code {
  margin-top: auto;
  width: fit-content;
  white-space: normal;
}

.layer-index {
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.layer-border-red { border-color: var(--red); }
.layer-border-teal { border-color: var(--teal); }
.layer-border-blue { border-color: var(--blue); }
.layer-border-gold { border-color: var(--gold); }
.layer-border-violet { border-color: var(--violet); }
.layer-border-green { border-color: var(--green); }
.layer-border-orange { border-color: var(--orange); }

.layer-red span { background: var(--red); }
.layer-teal span { background: var(--teal); }
.layer-blue span { background: var(--blue); }
.layer-gold span { background: var(--gold); }
.layer-violet span { background: var(--violet); }
.layer-green span { background: var(--green); }
.layer-orange span { background: var(--orange); }

.spec-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  font-size: 0.95rem;
}

.spec-table th,
.spec-table td {
  padding: 0.85rem;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.spec-table th {
  width: 10rem;
  color: #303640;
  background: #f0f2ef;
}

.spec-table tr:last-child th,
.spec-table tr:last-child td {
  border-bottom: 0;
}

.compact {
  font-size: 0.88rem;
}

.compact th,
.compact td {
  padding: 0.65rem;
}

.diagram {
  overflow: hidden;
  box-shadow: var(--shadow);
}

.diagram img {
  width: 100%;
  background: #fbfcfa;
}

.diagram figcaption {
  padding: 0.8rem 1rem;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 0.9rem;
}

.chart-grid {
  align-items: stretch;
}

.chart-grid .diagram:nth-child(3) {
  grid-column: 1 / -1;
}

.gap-grid article,
.check-grid article,
.step-grid article {
  padding: 1rem;
}

.gap-grid article {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.94);
  border-color: rgba(255, 255, 255, 0.18);
}

.gap-grid strong,
.check-grid strong,
.step-grid strong {
  display: block;
  margin-bottom: 0.4rem;
  line-height: 1.2;
}

.gap-grid span,
.check-grid span,
.step-grid p {
  color: var(--muted);
  font-size: 0.95rem;
}

.band-ink .gap-grid span { color: #4d5662; }

.two-col {
  align-items: stretch;
}

.example,
.template-panel,
.layer-summary,
.callout {
  padding: 1rem;
}

.example.good {
  border-top: 5px solid var(--teal);
}

.example.poor {
  border-top: 5px solid var(--red);
}

.rule-stack {
  display: grid;
  gap: 1rem;
}

.rule-stack article {
  padding: 1rem;
  background: var(--white);
  border-left: 5px solid var(--teal);
  border-radius: var(--radius);
  box-shadow: 0 12px 28px rgba(23, 26, 31, 0.08);
}

.rule-stack span {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.template-panel h3 {
  margin-bottom: 1rem;
}

.callout {
  margin-top: 1rem;
  border-left-width: 6px;
}

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

.callout-info { border-left-color: var(--blue); }
.callout-warn { border-left-color: var(--gold); }

.protocol-list {
  display: grid;
  gap: 0.6rem;
  padding-left: 1.35rem;
}

.protocol-list li {
  padding-left: 0.25rem;
}

.step-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.step-grid article span {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  margin-bottom: 0.8rem;
  color: var(--white);
  background: var(--ink);
  border-radius: 5px;
  font-weight: 850;
}

.site-footer {
  padding: 2rem 0;
  color: rgba(255, 255, 255, 0.74);
  background: #101216;
}

.footer-grid {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
}

.footer-grid p {
  max-width: 58ch;
  margin: 0.35rem 0 0;
}

.footer-grid div:last-child {
  display: grid;
  justify-items: end;
  gap: 0.25rem;
  min-width: max-content;
}

.footer-grid a {
  color: var(--white);
}

@media (max-width: 980px) {
  .header-inner {
    align-items: flex-start;
    flex-direction: column;
    padding-block: 1rem;
  }

  .primary-nav {
    justify-content: flex-start;
  }

  .hero-grid,
  .split,
  .two-col,
  .chart-grid {
    grid-template-columns: 1fr;
  }

  .layer-grid {
    grid-template-columns: repeat(3, minmax(190px, 1fr));
  }

  .gap-grid,
  .check-grid,
  .step-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero {
    min-height: auto;
  }
}

@media (max-width: 640px) {
  .shell {
    width: calc(100% - 1rem);
  }

  .band {
    padding: 3.25rem 0;
  }

  .hero-small {
    padding: 3rem 0 2.5rem;
  }

  h1 {
    font-size: 3.1rem;
  }

  .hero-small h1,
  .layer-hero h1 {
    font-size: 2.65rem;
  }

  h2 {
    font-size: 2rem;
  }

  .primary-nav {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .nav-link {
    justify-content: flex-start;
  }

  .layer-grid,
  .gap-grid,
  .check-grid,
  .step-grid {
    grid-template-columns: 1fr;
  }

  .spec-table {
    display: block;
    overflow: hidden;
    white-space: nowrap;
  }

  .spec-table thead {
    display: none;
  }

  .spec-table tbody,
  .spec-table tr,
  .spec-table th,
  .spec-table td {
    display: block;
    width: 100%;
    min-width: 0;
    white-space: normal;
  }

  .spec-table tr {
    border-bottom: 1px solid var(--line);
  }

  .spec-table tr:last-child {
    border-bottom: 0;
  }

  .spec-table th,
  .spec-table td {
    border-bottom: 0;
  }

  .hero-actions,
  .footer-grid {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  pre {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
  }

  pre code {
    white-space: inherit;
  }

  .footer-grid div:last-child {
    justify-items: start;
    min-width: 0;
  }
}

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