/*
  Keelson documentation design system.
  Adapted from the chamber user-guide component vocabulary, reskinned to the
  keelson "blueprint" identity: deep-navy structure, a single brass accent, a
  faint blueprint grid. One stylesheet for every page (landing links it too,
  then adds only its hero-specific rules inline).
*/

:root {
  color-scheme: light;
  --ink: #0f1b2d;          /* deep navy ink for body text */
  --muted: #51607a;        /* slate-blue secondary text */
  --line: rgba(15, 27, 45, 0.14);
  --panel: rgba(255, 255, 255, 0.70);
  --panel-strong: rgba(255, 255, 255, 0.86);
  --keel: #1e3a5f;         /* the harness / backbone navy */
  --keel-deep: #14283f;
  --rib: #2f6fb0;          /* ribs / extensions ocean blue */
  --brass: #b5803a;        /* brass accent: emphasis and interaction */
  --brass-ink: #8a5a1f;    /* deeper brass for small text contrast */
  --brass-soft: rgba(181, 128, 58, 0.13);
  --green: #2f8f5b;        /* success / check */
  --grid: rgba(30, 58, 95, 0.055);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 74% 0%, rgba(255, 255, 255, 0.95), transparent 19rem),
    radial-gradient(circle at 76% 42%, rgba(181, 128, 58, 0.12), transparent 13rem),
    linear-gradient(180deg, #f3f5f8 0%, #e6eaf0 100%);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  overflow-x: hidden;
}

/* faint blueprint grid, fading toward the bottom */
body::before {
  position: fixed;
  inset: 0;
  z-index: -2;
  content: "";
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(to bottom, black, transparent 84%);
}

/* a soft waterline shadow anchoring the page */
body::after {
  position: fixed;
  inset: auto -8vw 0 -8vw;
  z-index: -1;
  height: 22vh;
  content: "";
  background:
    radial-gradient(ellipse at center, rgba(15, 27, 45, 0.26), transparent 36%),
    linear-gradient(180deg, transparent, rgba(15, 27, 45, 0.1));
  filter: blur(2px);
}

a {
  color: inherit;
}

/* ---- shell + header --------------------------------------------------- */

.guide-shell {
  width: min(1320px, calc(100vw - 48px));
  margin: 0 auto;
  padding: 42px 0 64px;
}

.site-header {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 34px;
  align-items: center;
  margin-bottom: clamp(54px, 9vh, 110px);
}

.brand {
  display: inline-flex;
  gap: 15px;
  align-items: center;
  color: var(--ink);
  text-decoration: none;
}

.brand-mark {
  width: 34px;
  height: 34px;
  border: 1px solid var(--line);
  border-radius: 4px;
  box-shadow: 0 0 0 7px rgba(181, 128, 58, 0.06);
}

.brand-word {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.46em;
}

.nav {
  display: flex;
  gap: clamp(18px, 3vw, 44px);
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.28em;
  text-transform: uppercase;
}

.nav a,
.github-link {
  color: rgba(15, 27, 45, 0.74);
  text-decoration: none;
}

.nav a:hover {
  color: var(--brass-ink);
}

.github-link {
  justify-self: end;
  display: inline-flex;
  gap: 14px;
  align-items: center;
  justify-content: center;
  min-width: 150px;
  padding: 14px 20px;
  border: 1px solid rgba(15, 27, 45, 0.32);
  border-radius: 6px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.26em;
  text-transform: uppercase;
}

/* ---- hero ------------------------------------------------------------- */

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(280px, 0.88fr);
  gap: clamp(30px, 7vw, 92px);
  align-items: end;
  margin-bottom: 56px;
}

.eyebrow {
  margin: 0 0 24px;
  color: var(--brass-ink);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.42em;
  text-transform: uppercase;
}

h1 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(40px, 5.6vw, 78px);
  font-weight: 300;
  line-height: 1.13;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.divider {
  width: 128px;
  height: 1px;
  margin: 28px 0 26px;
  background: linear-gradient(90deg, var(--line), var(--brass), var(--line));
}

.hero-copy,
.lead {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
}

.hero-copy {
  max-width: 620px;
  margin: 0;
}

/* ---- shared card surfaces -------------------------------------------- */

.hero-card,
.callout,
.content-card,
.step,
.link-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(16px);
}

.hero-card {
  padding: 28px;
}

.hero-card h2,
.content-card h2,
.section-heading {
  margin: 0 0 14px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.26em;
  text-transform: uppercase;
}

.hero-card p,
.content-card p,
.step p,
.callout p,
.link-card p {
  margin: 0;
  color: rgba(15, 27, 45, 0.6);
  font-size: 14px;
  line-height: 1.7;
}

/* ---- guide layout: sticky on-this-page + content column -------------- */

.guide-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 36px;
  align-items: start;
}

.side-nav {
  position: sticky;
  top: 24px;
  display: grid;
  gap: 8px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.56);
}

.side-nav strong {
  margin-bottom: 8px;
  color: var(--brass-ink);
  font-size: 11px;
  letter-spacing: 0.26em;
  text-transform: uppercase;
}

.side-nav a {
  padding: 9px 10px;
  border-radius: 7px;
  color: rgba(15, 27, 45, 0.72);
  font-size: 13px;
  line-height: 1.35;
  text-decoration: none;
}

.side-nav a[aria-current="page"],
.side-nav a:hover {
  background: var(--brass-soft);
  color: var(--ink);
}

.guide-content {
  display: grid;
  gap: 28px;
}

/* ---- hub: card grid of topic links ----------------------------------- */

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.link-card {
  display: grid;
  min-height: 180px;
  padding: 24px;
  color: inherit;
  text-decoration: none;
  transition: transform 0.16s ease, box-shadow 0.16s ease;
}

.link-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 40px rgba(15, 27, 45, 0.12);
}

.link-card span {
  color: var(--brass-ink);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.26em;
  text-transform: uppercase;
}

.link-card h2,
.link-card h3 {
  margin: 22px 0 12px;
  font-size: 19px;
  font-weight: 500;
  line-height: 1.3;
}

/* ---- content cards (the body of a topic page) ------------------------ */

.content-card {
  padding: clamp(24px, 4vw, 38px);
}

.content-card h3 {
  margin: 28px 0 10px;
  font-size: 18px;
}

.content-card ul,
.content-card ol {
  margin: 16px 0 0;
  padding-left: 22px;
  color: rgba(15, 27, 45, 0.7);
  line-height: 1.75;
}

.content-card li + li {
  margin-top: 6px;
}

/* the column is wide, but prose keeps a comfortable ~72-character measure;
   tables, figures, and code are free to use the full width */
.content-card > p,
.content-card > ul,
.content-card > ol {
  max-width: 72ch;
  font-size: 15px;
}

.content-card code {
  padding: 2px 5px;
  border: 1px solid rgba(15, 27, 45, 0.1);
  border-radius: 5px;
  background: rgba(255, 255, 255, 0.66);
  color: var(--keel-deep);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.92em;
}

/* ---- figures: diagrams (light) and screenshots (dark) ---------------- */

.diagram-figure {
  margin: 24px 0 0;
}

.diagram-figure img {
  display: block;
  width: 100%;
  height: auto;
  padding: 14px;
  border: 1px solid rgba(15, 27, 45, 0.12);
  border-radius: 12px;
  background:
    radial-gradient(circle at 50% 0%, rgba(255, 255, 255, 0.9), transparent 60%),
    rgba(255, 255, 255, 0.78);
  box-shadow: 0 18px 44px rgba(15, 27, 45, 0.1);
}

.screenshot-figure {
  margin: 22px 0 0;
}

.screenshot-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid rgba(15, 27, 45, 0.16);
  border-radius: 12px;
  background: rgba(15, 27, 45, 0.9);
  box-shadow: 0 24px 60px rgba(15, 27, 45, 0.18);
}

.diagram-figure figcaption,
.screenshot-figure figcaption {
  margin-top: 10px;
  color: rgba(15, 27, 45, 0.54);
  font-size: 13px;
  line-height: 1.6;
}

/* ---- code samples ---------------------------------------------------- */

.code-sample {
  margin: 18px 0 0;
  padding: 18px;
  overflow-x: auto;
  border: 1px solid rgba(15, 27, 45, 0.14);
  border-radius: 10px;
  background: var(--keel-deep);
  color: rgba(255, 255, 255, 0.92);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 13px;
  line-height: 1.65;
}

.code-sample .c { color: #8aa0bf; }   /* comment */
.code-sample .k { color: #d8a657; }   /* keyword / command */
.code-sample .s { color: #8fce96; }   /* string / value */

/* ---- reference tables ------------------------------------------------ */

.info-table {
  width: 100%;
  margin-top: 18px;
  border-collapse: collapse;
  color: rgba(15, 27, 45, 0.7);
  font-size: 14px;
  line-height: 1.6;
}

.info-table th,
.info-table td {
  padding: 12px 0;
  border-bottom: 1px solid rgba(15, 27, 45, 0.1);
  text-align: left;
  vertical-align: top;
}

.info-table thead th {
  color: var(--ink);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.info-table tbody th {
  width: 30%;
  color: var(--ink);
  font-weight: 600;
}

.info-table code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.9em;
  color: var(--keel-deep);
}

/* ---- numbered steps -------------------------------------------------- */

.steps {
  display: grid;
  gap: 14px;
  margin-top: 18px;
}

.step {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 18px;
  padding: 20px;
}

.step-number {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 1px solid rgba(181, 128, 58, 0.34);
  border-radius: 999px;
  color: var(--brass-ink);
  font-weight: 700;
}

.step h3 {
  margin: 0 0 6px;
  font-size: 17px;
}

/* ---- callouts (semantic admonitions) --------------------------------- */

.callout {
  padding: 22px 24px;
  border-color: rgba(181, 128, 58, 0.3);
  background: var(--brass-soft);
}

.callout strong {
  display: block;
  margin-bottom: 8px;
  color: var(--brass-ink);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

.callout-keel {
  border-color: rgba(47, 111, 176, 0.32);
  background: rgba(47, 111, 176, 0.09);
}

.callout-keel strong {
  color: var(--keel);
}

/* ---- related links + buttons ----------------------------------------- */

.related {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 12px;
}

.related a,
.button {
  display: inline-flex;
  min-height: 42px;
  padding: 0 18px;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(15, 27, 45, 0.22);
  border-radius: 6px;
  color: var(--ink);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-decoration: none;
  text-transform: uppercase;
}

.button-primary {
  border-color: transparent;
  background: linear-gradient(135deg, #c79452, #9a6420);
  color: #fff;
  box-shadow: 0 18px 40px rgba(154, 100, 32, 0.26);
}

/* ---- footer ---------------------------------------------------------- */

.page-footer {
  margin-top: 54px;
  padding-top: 26px;
  border-top: 1px solid var(--line);
  color: rgba(15, 27, 45, 0.46);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

/* ---- responsive ------------------------------------------------------ */

@media (max-width: 980px) {
  .site-header,
  .hero,
  .guide-layout {
    grid-template-columns: 1fr;
  }

  .github-link,
  .nav {
    justify-self: start;
  }

  .side-nav {
    position: static;
  }

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

@media (max-width: 680px) {
  .guide-shell {
    width: min(100% - 28px, 1180px);
    padding-top: 28px;
  }

  .nav {
    display: none;
  }

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

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