:root {
  --paper: #f6f2e9;
  --paper-deep: #eee7d9;
  --ink: #17191d;
  --muted: #5d625f;
  --line: #d1c9b9;
  --blue: #1649d8;
  --blue-dark: #0e318f;
  --orange: #a64218;
  --green: #1e6b52;
  --white: #fffdf8;
  --shadow: 0 18px 50px rgba(35, 31, 23, 0.08);
  color-scheme: light;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(rgba(23, 25, 29, 0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 25, 29, 0.028) 1px, transparent 1px),
    var(--paper);
  background-size: 32px 32px;
  font-size: 17px;
  line-height: 1.65;
}

a {
  color: inherit;
  text-underline-offset: 0.2em;
  text-decoration-thickness: 1px;
}

a:hover {
  color: var(--blue);
}

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

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

code {
  font-size: 0.9em;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.6rem 0.9rem;
  background: var(--ink);
  color: white;
  transform: translateY(-180%);
}

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

.site-header,
footer,
.hero,
.proof-strip,
.section {
  width: min(1180px, calc(100% - 48px));
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  padding-block: 1.35rem;
  border-bottom: 1px solid var(--line);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 0.62rem;
  font-weight: 760;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.wordmark-mark {
  display: inline-grid;
  width: 2.1rem;
  height: 2.1rem;
  place-items: center;
  border-radius: 50%;
  color: white;
  background: var(--blue);
  font-family: Georgia, serif;
  font-size: 0.82rem;
}

nav {
  display: flex;
  align-items: center;
  gap: 1.35rem;
  font-size: 0.86rem;
  font-weight: 650;
}

nav a {
  text-decoration: none;
}

.hero {
  padding-block: clamp(5rem, 10vw, 9rem) clamp(4rem, 8vw, 7rem);
}

.eyebrow,
.kicker {
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

.hero h1 {
  max-width: 940px;
  margin: 0.75rem 0 1.25rem;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(3.2rem, 7.5vw, 7.1rem);
  font-weight: 500;
  letter-spacing: -0.065em;
  line-height: 0.96;
}

.hero-copy {
  max-width: 790px;
  margin: 0;
  color: var(--muted);
  font-size: clamp(1.08rem, 2vw, 1.35rem);
  line-height: 1.55;
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3rem;
  padding: 0.68rem 1.05rem;
  border: 1px solid var(--ink);
  border-radius: 3px;
  font-size: 0.9rem;
  font-weight: 720;
  text-decoration: none;
}

.button:hover {
  border-color: var(--blue);
  color: var(--blue);
}

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

.button-primary:hover {
  border-color: var(--blue-dark);
  background: var(--blue-dark);
  color: white;
}

.install-peek {
  display: flex;
  align-items: center;
  gap: 1rem;
  width: fit-content;
  max-width: 100%;
  margin-top: 2.5rem;
  padding: 0.75rem 0.9rem;
  border-left: 3px solid var(--orange);
  background: rgba(255, 253, 248, 0.72);
  box-shadow: var(--shadow);
  overflow-x: auto;
  white-space: nowrap;
}

.install-peek span {
  color: var(--orange);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.proof-strip {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  border-block: 1px solid var(--line);
  background: rgba(255, 253, 248, 0.5);
}

.proof-strip span {
  display: grid;
  min-height: 5.5rem;
  padding: 1rem;
  place-items: center;
  border-right: 1px solid var(--line);
  font-size: 0.8rem;
  font-weight: 760;
  text-align: center;
}

.proof-strip span:last-child {
  border-right: 0;
}

.section {
  padding-block: clamp(5rem, 9vw, 8rem);
  border-bottom: 1px solid var(--line);
}

.section-heading {
  max-width: 800px;
  margin-bottom: 2.75rem;
}

.section-heading.compact {
  margin-bottom: 2rem;
}

.section h2 {
  margin: 0.35rem 0 0.8rem;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2.2rem, 4.8vw, 4.5rem);
  font-weight: 500;
  letter-spacing: -0.045em;
  line-height: 1.03;
}

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

.diagnostic-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(280px, 0.75fr);
  gap: 1.25rem;
  align-items: stretch;
}

.plot-card,
.value-card,
.question-grid article,
.boundary-card,
.env-grid article,
.manifest {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--white);
  box-shadow: var(--shadow);
}

.plot-card {
  overflow: hidden;
}

.plot-card img {
  width: 100%;
  background: white;
}

.plot-card figcaption {
  padding: 1rem 1.2rem 1.15rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.88rem;
}

.value-card {
  display: flex;
  flex-direction: column;
  padding: 1.25rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-variant-numeric: tabular-nums;
}

caption {
  margin-bottom: 0.85rem;
  font-size: 0.8rem;
  font-weight: 760;
  text-align: left;
}

th,
td {
  padding: 0.62rem 0.38rem;
  border-bottom: 1px solid var(--line);
  font-size: 0.82rem;
  text-align: right;
}

th:first-child {
  text-align: left;
}

.oracle {
  color: var(--green);
}

.caveat {
  margin: 1.15rem 0;
  color: var(--muted);
  font-size: 0.83rem;
}

.text-link {
  margin-top: auto;
  color: var(--blue);
  font-size: 0.84rem;
  font-weight: 750;
  text-decoration: none;
}

.question-grid,
.env-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.question-grid article {
  padding: clamp(1.6rem, 4vw, 3rem);
}

.question-number,
.env-index {
  color: var(--orange);
  font-family: Georgia, serif;
  font-size: 0.9rem;
  font-style: italic;
}

.question-grid h3,
.env-grid h3,
.boundary-card h3,
.manifest h3,
.chip-groups h3,
.code-grid h3 {
  margin: 0.55rem 0;
  font-size: 1.08rem;
}

.question-grid p,
.env-grid p,
.boundary-card p,
.manifest p {
  color: var(--muted);
}

.question-grid ul,
.manifest ul {
  padding-left: 1.1rem;
  font-size: 0.88rem;
}

.use-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(280px, 0.7fr);
  gap: 2.25rem;
  align-items: start;
}

.check-list {
  display: grid;
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding: 0 0 1rem 2rem;
  border-bottom: 1px solid var(--line);
}

.check-list li::before {
  position: absolute;
  left: 0;
  color: var(--blue);
  content: "✓";
  font-weight: 900;
}

.boundary-card {
  padding: 1.45rem;
  border-top: 3px solid var(--orange);
}

.env-grid {
  grid-template-columns: repeat(3, 1fr);
}

.env-grid article {
  min-height: 15rem;
  padding: 1.4rem;
}

.env-grid strong {
  display: inline-block;
  margin-top: 0.5rem;
  color: var(--blue);
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.chip-groups {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 2rem;
  padding: 1.5rem;
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, 0.65);
}

.chip-groups p {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.chip-groups span {
  padding: 0.42rem 0.62rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--white);
  font-size: 0.76rem;
  font-weight: 680;
}

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.plot-card.wide {
  grid-column: 1 / -1;
}

.manifest {
  padding: 1.5rem;
  border-top: 3px solid var(--blue);
}

.manifest li {
  margin-bottom: 0.65rem;
}

.code-grid {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 1.25rem;
}

.code-grid > div {
  min-width: 0;
}

pre {
  max-width: 100%;
  margin: 0;
  padding: 1.25rem;
  overflow-x: auto;
  border: 1px solid #2b2d33;
  border-radius: 3px;
  color: #f5f3ed;
  background: #1d2027;
  font-size: 0.78rem;
  line-height: 1.65;
  box-shadow: var(--shadow);
}

.faq details {
  border-top: 1px solid var(--line);
}

.faq details:last-child {
  border-bottom: 1px solid var(--line);
}

.faq summary {
  padding: 1.2rem 2rem 1.2rem 0;
  cursor: pointer;
  font-weight: 740;
}

.faq details p {
  max-width: 800px;
  margin-top: 0;
  color: var(--muted);
}

.citation {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 3rem;
  align-items: center;
}

.citation h2 {
  font-size: clamp(2.2rem, 4vw, 3.8rem);
}

footer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.5rem 2rem;
  padding-block: 2.5rem 4rem;
  color: var(--muted);
  font-size: 0.8rem;
}

footer .wordmark {
  color: var(--ink);
}

footer p {
  margin: 0;
}

footer p:last-child {
  grid-column: 2;
  grid-row: 1 / span 2;
  align-self: center;
}

@media (max-width: 900px) {
  nav a:not(:last-child) {
    display: none;
  }

  .proof-strip {
    grid-template-columns: repeat(2, 1fr);
  }

  .proof-strip span {
    border-bottom: 1px solid var(--line);
  }

  .proof-strip span:nth-child(2n) {
    border-right: 0;
  }

  .diagnostic-layout,
  .use-grid,
  .chip-groups,
  .code-grid,
  .citation {
    grid-template-columns: 1fr;
  }

  .env-grid {
    grid-template-columns: 1fr;
  }

  .env-grid article {
    min-height: auto;
  }

  footer {
    grid-template-columns: 1fr;
  }

  footer p:last-child {
    grid-column: auto;
    grid-row: auto;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 16px;
  }

  .site-header,
  footer,
  .hero,
  .proof-strip,
  .section {
    width: min(100% - 28px, 1180px);
  }

  .hero h1 {
    font-size: clamp(2.7rem, 14vw, 4.3rem);
  }

  .question-grid,
  .evidence-grid {
    grid-template-columns: 1fr;
  }

  .plot-card.wide {
    grid-column: auto;
  }

  .install-peek {
    width: 100%;
  }
}

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