/* ==========================================================================
   Perceptron — datasheet stylesheet
   Engineering-datasheet aesthetic: hairline rules, numbered sections,
   monospace labels, grid-paper panels, hard offset-shadow buttons.
   ========================================================================== */

:root {
  --paper: #f5f3e9;
  --desk: #eae8de;
  --ink: #22403c;
  --deep-ink: #14302c;
  --text: #41564f;
  --mono-muted: #5c7a70;
  --hairline: #a9b8a9;
  --accent: #e07830;
  --accent-dark: #c66520;
  --footer-link: #9cb99c;
  --sage: #7aa37a;
  --code-bg: #e6ede6;

  --mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --pad-x: 56px;
  --shell-x: 40px;
}

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

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

body {
  margin: 0;
  padding: 0 20px;
  background: var(--desk);
  color: var(--ink);
  font-family: 'Archivo', system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.55;
}

a { color: var(--accent-dark); text-decoration: none; }
a:hover { color: var(--accent); }

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

h1, h2, h3, h4 { margin: 0; }

code {
  font-family: var(--mono);
  font-size: 12px;
  background: var(--code-bg);
  padding: 1px 6px;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.mono { font-family: var(--mono); }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #fff;
  font-family: var(--mono);
  font-size: 13px;
  padding: 12px 20px;
  border: 1px solid var(--ink);
  z-index: 100;
}
.skip-link:focus {
  left: 20px;
  top: 20px;
  color: #fff;
}

/* --------------------------------------------------------------------------
   Sheet, header, footer
   -------------------------------------------------------------------------- */

.sheet {
  max-width: 1240px;
  margin: 40px auto;
  border: 1px solid var(--ink);
  background: var(--paper);
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 0 var(--shell-x);
  height: 76px;
  border-bottom: 1px solid var(--ink);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
  color: var(--ink);
}
.brand:hover { color: var(--ink); }

.brand-mark {
  width: 42px;
  height: 42px;
  border: 1px solid var(--ink);
  display: block;
  flex-shrink: 0;
}

.logotype { display: flex; flex-direction: column; min-width: 0; overflow: hidden; }
.logotype b {
  font-weight: 800;
  font-size: 19px;
  letter-spacing: 2px;
  line-height: 1.2;
}
.logotype span {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 2px;
  color: var(--mono-muted);
  white-space: nowrap;
}

.site-nav {
  display: flex;
  gap: 36px;
  align-items: center;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 1px;
}
.site-nav a {
  color: var(--mono-muted);
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
}
.site-nav a:hover { color: var(--ink); }
.site-nav a[aria-current="page"] {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--ink);
  color: var(--ink);
  cursor: pointer;
}
.nav-toggle svg { width: 20px; height: 20px; display: block; }

.mobile-nav { display: none; }
.mobile-nav.is-open {
  display: flex;
  flex-direction: column;
  border-bottom: 1px solid var(--ink);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 1px;
}
.mobile-nav a {
  color: var(--mono-muted);
  padding: 16px var(--shell-x);
  border-bottom: 1px solid var(--hairline);
}
.mobile-nav a:last-child { border-bottom: 0; }
.mobile-nav a[aria-current="page"] {
  color: var(--ink);
  border-left: 3px solid var(--accent);
}

.site-footer {
  border-top: 1px solid var(--ink);
  background: var(--deep-ink);
  color: var(--footer-link);
  padding: 28px var(--shell-x);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 1px;
}
.footer-mark { color: var(--paper); }
.footer-links { display: flex; flex-wrap: wrap; gap: 28px; }
.footer-links a { color: var(--footer-link); }
.footer-links a:hover { color: var(--paper); }

/* --------------------------------------------------------------------------
   Section furniture
   -------------------------------------------------------------------------- */

.grid-paper {
  background-image:
    repeating-linear-gradient(0deg, rgba(34, 64, 60, 0.05) 0 1px, transparent 1px 32px),
    repeating-linear-gradient(90deg, rgba(34, 64, 60, 0.05) 0 1px, transparent 1px 32px);
}

.section {
  padding: 48px var(--pad-x);
  border-bottom: 1px solid var(--ink);
}
.section--end { border-bottom: 0; }

.label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--accent-dark);
  margin-bottom: 24px;
}
.label--tight { margin-bottom: 16px; }

.page-head {
  padding: 64px var(--pad-x) 48px;
  border-bottom: 1px solid var(--ink);
}
.page-head h1 {
  font-size: 46px;
  font-weight: 800;
  letter-spacing: -1px;
  line-height: 1.05;
  margin: 0 0 14px;
}
.page-head h1:last-child { margin-bottom: 0; }
.page-head p {
  font-size: 18px;
  color: var(--text);
  margin: 0;
  max-width: 720px;
}
.page-head strong { color: var(--ink); }

.section-lede {
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  margin: 0 0 24px;
  max-width: 640px;
}

.note {
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.6;
  color: var(--mono-muted);
  margin: 16px 0 0;
}

/* Divided grids — the 1px gap over an ink/hairline backdrop draws the rules,
   so they reflow correctly at every breakpoint. */
.hero,
.split,
.features {
  display: grid;
  gap: 1px;
  background: var(--ink);
  border-bottom: 1px solid var(--ink);
}
.hero > *,
.split > *,
.features > * { background-color: var(--paper); min-width: 0; }

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

.cell-grid {
  display: grid;
  gap: 1px;
  background: var(--hairline);
  border: 1px solid var(--hairline);
}
.cell-grid > * {
  min-width: 0;
  background-color: var(--paper);
  padding: 26px 30px;
}
.cell-grid--2 { grid-template-columns: 1fr 1fr; }
.cell-grid--3 { grid-template-columns: repeat(3, 1fr); }
.cell-grid h3 { font-size: 17px; font-weight: 700; margin: 0 0 10px; }
.cell-grid p { font-size: 14px; line-height: 1.6; color: var(--text); margin: 0; }

.pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.pair--wide { gap: 32px; }

/* --------------------------------------------------------------------------
   Buttons and links
   -------------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 1px;
  padding: 16px 30px;
  border: 1px solid var(--ink);
  text-align: center;
  cursor: pointer;
}

.btn--primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 4px 4px 0 var(--ink);
}
.btn--primary:hover { background: var(--accent-dark); color: #fff; }

.btn--secondary {
  background: transparent;
  color: var(--ink);
  font-weight: 500;
}
.btn--secondary:hover { background: var(--ink); color: var(--paper); }

.btn--block { display: flex; width: 100%; }
.btn--small { font-size: 14px; padding: 14px 24px; font-weight: 500; }
.btn--started {
  background: var(--sage);
  box-shadow: 4px 4px 0 var(--ink);
  color: #fff;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  margin-bottom: 40px;
}

.band {
  padding: 56px 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 32px;
}
.band h2 {
  font-size: 30px;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin: 0;
}

/* --------------------------------------------------------------------------
   Tables
   -------------------------------------------------------------------------- */

.table-scroll { overflow-x: auto; }

.spec-table {
  border-collapse: collapse;
  font-family: var(--mono);
  font-size: 12px;
  width: 100%;
  max-width: 460px;
}
.spec-table td {
  border: 1px solid var(--hairline);
  padding: 8px 12px;
  text-align: left;
}
.spec-table .key { color: var(--mono-muted); width: 130px; }

.data-table {
  border-collapse: collapse;
  width: 100%;
  font-size: 14px;
}
.data-table th {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--mono-muted);
  font-weight: 500;
  text-align: left;
  border: 1px solid var(--hairline);
  padding: 10px 14px;
}
.data-table td {
  border: 1px solid var(--hairline);
  padding: 10px 14px;
  color: var(--text);
}
.data-table .k {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--mono-muted);
}
.data-table .name { font-weight: 700; color: var(--ink); }
.data-table .lic { font-family: var(--mono); font-size: 12px; color: var(--ink); }

/* --------------------------------------------------------------------------
   Figures
   -------------------------------------------------------------------------- */

.figure {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin: 0;
}
.figure-frame {
  border: 1px solid var(--ink);
  background: var(--deep-ink);
  padding: 10px;
}
.figure-frame img { width: 100%; height: auto; display: block; }
.figure-caption {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--mono-muted);
  display: flex;
  justify-content: space-between;
  gap: 16px;
}

/* --------------------------------------------------------------------------
   Lists and cards
   -------------------------------------------------------------------------- */

.accent-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.accent-list li {
  border-left: 3px solid var(--accent);
  padding-left: 16px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
}
.accent-list li strong { color: var(--ink); }

.accent-list--mono { gap: 12px; }
.accent-list--mono li {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--ink);
  padding-left: 14px;
}
.accent-list--tight { gap: 10px; }
.accent-list--sm li { font-size: 14px; padding-left: 12px; }
.accent-list--sage li { border-left-color: var(--sage); }
.accent-list--deny li { border-left-color: var(--accent-dark); }

.dash-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--text);
}

.card {
  border: 1px solid var(--hairline);
  padding: 24px 28px;
}
.card--ink { border-color: var(--ink); }
.card h3 { font-size: 18px; font-weight: 700; margin: 0 0 8px; }
.card p { font-size: 14px; line-height: 1.6; color: var(--text); margin: 0 0 12px; }
.card p:last-child { margin-bottom: 0; }
.card ol {
  margin: 0;
  padding-left: 18px;
  font-size: 14px;
  line-height: 2;
  color: var(--text);
}
.card ol strong { color: var(--ink); }

.card-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--mono-muted);
  margin-bottom: 14px;
}

.link-card {
  border: 1px solid var(--ink);
  padding: 24px 28px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  color: var(--ink);
}
.link-card:hover { color: var(--ink); background: var(--code-bg); }
.link-card b { display: block; font-weight: 700; font-size: 17px; }
.link-card .sub {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--mono-muted);
  margin-top: 4px;
}
.link-card .glyph { font-family: var(--mono); color: var(--accent-dark); }

/* --------------------------------------------------------------------------
   Home
   -------------------------------------------------------------------------- */

.hero-copy { padding: 72px var(--pad-x); }
.hero-copy h1 {
  font-size: 56px;
  line-height: 1.02;
  font-weight: 800;
  letter-spacing: -1px;
  margin: 0 0 28px;
}
.hero-copy > p {
  font-size: 18px;
  line-height: 1.6;
  color: var(--text);
  margin: 0 0 36px;
  max-width: 480px;
}

.hero-figure {
  padding: 56px 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.feature { padding: 44px 48px; }
.feature .label { letter-spacing: 2px; margin-bottom: 14px; }
.feature h3 { font-size: 21px; font-weight: 700; margin: 0 0 10px; }
.feature p { font-size: 15px; line-height: 1.55; color: var(--text); margin: 0; }

.sources {
  display: grid;
  grid-template-columns: 220px repeat(4, 1fr);
  gap: 1px;
  background: var(--hairline);
  border-bottom: 1px solid var(--ink);
}
.sources > * { background-color: var(--paper); min-width: 0; }
.sources-label {
  background-color: var(--ink);
  color: var(--paper);
  padding: 32px 40px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 2px;
  line-height: 1.8;
  display: flex;
  align-items: center;
}
.source { padding: 28px 32px; }
.source b { display: block; font-weight: 800; font-size: 22px; }
.source span {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--mono-muted);
  margin-top: 6px;
}

.split-copy { padding: 72px var(--pad-x); }
.split-copy h2 {
  font-size: 36px;
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin: 0 0 22px;
}
.split-copy > p {
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
  margin: 0 0 26px;
  max-width: 460px;
}

.split-figure {
  padding: 56px 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* --------------------------------------------------------------------------
   Docs
   -------------------------------------------------------------------------- */

.docs-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 1px;
  background: var(--ink);
}
/* Grid items default to min-width:auto, which lets wide content (tables,
   long tokens) push the column past the viewport. */
.docs-layout > * { background-color: var(--paper); min-width: 0; }

.docs-nav-inner {
  position: sticky;
  top: 20px;
  padding: 40px 32px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 1px;
}
.toc-title {
  color: var(--mono-muted);
  letter-spacing: 3px;
  margin-bottom: 16px;
}
.toc {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.toc a { color: var(--ink); }
.toc a:hover { color: var(--accent-dark); }

.docs-main section[id] { scroll-margin-top: 20px; }

.steps { border-top: 1px solid var(--hairline); }
.step {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 24px;
  padding: 22px 0;
  border-bottom: 1px solid var(--hairline);
}
.step-no {
  font-family: var(--mono);
  font-size: 24px;
  font-weight: 600;
  color: var(--accent);
  line-height: 1.2;
}
.step h3 { font-size: 18px; font-weight: 700; margin: 0 0 6px; }
.step p { font-size: 15px; line-height: 1.6; color: var(--text); margin: 0; }

.support-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 32px;
  border: 1px solid var(--ink);
  padding: 28px 32px;
}
.support-row p { font-size: 16px; color: var(--text); margin: 0; }
.support-links {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  font-family: var(--mono);
  font-size: 13px;
}

/* --------------------------------------------------------------------------
   Download
   -------------------------------------------------------------------------- */

.platform { padding: 48px var(--pad-x); }
.platform h2 { font-size: 28px; font-weight: 800; margin: 0 0 6px; }
.platform-tag {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--mono-muted);
  margin-bottom: 8px;
}
.platform-spec {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--mono-muted);
  margin: 0 0 28px;
}
.platform-alt { font-family: var(--mono); font-size: 12px; margin-top: 18px; }

/* Applied by the platform-detection script. Inset so nothing shifts. */
.platform.is-recommended { box-shadow: inset 0 0 0 2px var(--accent); }
.recommended-flag { color: var(--accent-dark); }

/* --------------------------------------------------------------------------
   Legal (privacy, terms)
   -------------------------------------------------------------------------- */

.legal { max-width: 860px; padding: 48px var(--pad-x) 24px; }
.legal-section { margin-bottom: 48px; }
.legal-section > .label {
  border-bottom: 1px solid var(--hairline);
  padding-bottom: 10px;
  margin-bottom: 20px;
}
.legal p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  margin: 0 0 16px;
}
.legal p:last-child { margin-bottom: 0; }
.legal-mono {
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.8;
  color: var(--text);
}

.clauses { display: flex; flex-direction: column; gap: 20px; }
.clause { display: grid; grid-template-columns: 56px 1fr; gap: 16px; }
.clause-no { font-family: var(--mono); font-size: 13px; color: var(--mono-muted); }
.clause-body { color: var(--text); }
.clause-body strong { color: var(--ink); }

/* --------------------------------------------------------------------------
   About
   -------------------------------------------------------------------------- */

.maker {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 1px;
  background: var(--ink);
  border-bottom: 1px solid var(--ink);
}
.maker > * { background-color: var(--paper); min-width: 0; }
.maker-mark {
  padding: 48px 32px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
}
.maker-mark img { width: 120px; height: 120px; border: 1px solid var(--ink); }
.maker-mark .label { margin-bottom: 0; }
.maker-bio { padding: 48px var(--pad-x); }
.maker-bio h2 { font-size: 28px; font-weight: 800; margin: 0 0 4px; }
.maker-bio .role {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 2px;
  color: var(--accent-dark);
  margin-bottom: 20px;
}
.maker-bio p {
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  margin: 0;
  max-width: 640px;
}

.why {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}
.why p {
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  margin: 0;
  border-left: 3px solid var(--accent);
  padding-left: 20px;
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */

@media (max-width: 1080px) {
  :root { --pad-x: 40px; --shell-x: 28px; }

  .hero,
  .split,
  .maker,
  .docs-layout { grid-template-columns: 1fr; }

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

  .sources { grid-template-columns: 1fr 1fr; }
  .sources-label { grid-column: 1 / -1; }

  .cell-grid--3 { grid-template-columns: 1fr 1fr; }

  .hero-copy,
  .split-copy { padding: 56px var(--pad-x); }
  .hero-copy h1 { font-size: 44px; }
  .split-copy h2 { font-size: 30px; }
  .hero-figure,
  .split-figure { padding: 40px var(--pad-x); }

  /* Reconcile section reads image-first once stacked. */
  .split--figure-first .split-figure { order: -1; }

  .docs-nav-inner { position: static; padding: 32px var(--pad-x); }
  .toc { flex-direction: row; flex-wrap: wrap; gap: 12px 24px; }

  .maker-mark { padding: 40px var(--pad-x) 0; }
  .maker-bio { padding: 32px var(--pad-x) 48px; }
}

@media (max-width: 880px) {
  .site-nav { display: none; }
  .nav-toggle { display: flex; }
}

@media (max-width: 720px) {
  :root { --pad-x: 24px; --shell-x: 20px; }

  body { padding: 0; }
  .sheet { margin: 0; border-left: 0; border-right: 0; border-top: 0; }

  .site-header { height: 68px; }
  .brand-mark { width: 36px; height: 36px; }
  .logotype b { font-size: 16px; letter-spacing: 1.5px; }

  .section { padding: 36px var(--pad-x); }
  .page-head { padding: 40px var(--pad-x) 32px; }
  .page-head h1 { font-size: 32px; letter-spacing: -0.5px; }
  .page-head p { font-size: 16px; }

  .hero-copy,
  .split-copy { padding: 40px var(--pad-x); }
  .hero-copy h1 { font-size: 34px; }
  .hero-copy > p { font-size: 16px; }
  .split-copy h2 { font-size: 26px; }
  .hero-figure,
  .split-figure { padding: 28px var(--pad-x); }

  .feature { padding: 32px var(--pad-x); }
  .feature h3 { font-size: 19px; }

  .sources { grid-template-columns: 1fr; }
  .sources-label { padding: 20px var(--pad-x); }
  .source { padding: 22px var(--pad-x); }

  .platform { padding: 32px var(--pad-x); }
  .legal { padding: 36px var(--pad-x) 8px; }
  .legal-section { margin-bottom: 36px; }

  .pair,
  .why,
  .cell-grid--2,
  .cell-grid--3 { grid-template-columns: 1fr; }

  .band { padding: 36px var(--pad-x); }
  .band h2 { font-size: 24px; }

  .btn { width: 100%; }
  .cta-row { gap: 12px; margin-bottom: 32px; }

  .step { grid-template-columns: 44px 1fr; gap: 16px; }
  .step-no { font-size: 20px; }

  .clause { grid-template-columns: 44px 1fr; gap: 12px; }

  .site-footer { padding: 24px var(--shell-x); }
  .footer-links { gap: 16px 20px; }

  .maker-mark img { width: 96px; height: 96px; }
  .maker-bio h2 { font-size: 24px; }

  .figure-caption { flex-direction: column; gap: 4px; }
}

@media (max-width: 400px) {
  .brand { gap: 10px; }
  .logotype b { font-size: 15px; letter-spacing: 1px; }
  .logotype span { font-size: 9px; letter-spacing: 0.5px; }
  .toc { flex-direction: column; }
}