/* KerPlace docs — clean, white, academic. Fixed left sidebar + readable column. */

:root {
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --bg-softer: #f1f5f9;
  --border: #e6eaf0;
  --border-strong: #d4dbe5;
  --ink: #0f172a;        /* headings */
  --body: #334155;       /* body text */
  --muted: #64748b;      /* secondary */
  --accent: #2563eb;     /* links / active */
  --accent-deep: #1e3a8a;
  --good: #166534;       /* matches the diagrams' "trusted" green */
  --code-bg: #f6f8fa;
  --sidebar-w: 268px;
  --measure: 760px;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--body);
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.layout { display: flex; align-items: flex-start; }

/* ---------- Sidebar ---------- */
.sidebar {
  position: sticky;
  top: 0;
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  height: 100vh;
  padding: 30px 22px;
  border-right: 1px solid var(--border);
  background: var(--bg-soft);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}
.brand { display: block; margin-bottom: 26px; }
.brand-mark {
  display: block;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.brand-accent { color: var(--accent-deep); }
.brand-sub {
  display: block;
  margin-top: 3px;
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}
.nav { display: flex; flex-direction: column; gap: 1px; flex: 1; }
.nav-link {
  display: block;
  padding: 7px 11px;
  border-radius: 7px;
  color: var(--body);
  font-size: 14.5px;
  font-weight: 500;
  border-left: 2px solid transparent;
}
.nav-link:hover { background: var(--bg-softer); text-decoration: none; }
.nav-link.active {
  background: #fff;
  color: var(--accent-deep);
  font-weight: 650;
  border-left-color: var(--accent);
  box-shadow: 0 1px 2px rgba(15,23,42,.04);
}
.nav-group {
  margin: 18px 0 6px;
  padding: 0 11px;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--muted);
}
.sidebar-foot {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 16px;
  font-size: 13px;
}
.sidebar-foot a { color: var(--muted); }

/* ---------- Content column ---------- */
.content {
  flex: 1;
  min-width: 0;
  padding: 56px clamp(24px, 6vw, 88px) 80px;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.content > * { width: 100%; max-width: var(--measure); }

.eyebrow {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

/* ---------- Doc header (SVG banner) ---------- */
.doc-head { margin-bottom: 30px; }
.doc-figure {
  margin-bottom: 26px;
  padding: 18px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 14px;
}
.doc-figure img { display: block; width: 100%; height: auto; }
.doc-head h1 {
  font-size: 38px;
  line-height: 1.15;
  letter-spacing: -0.022em;
  color: var(--ink);
  margin: 0 0 12px;
}
.lead {
  font-size: 19px;
  line-height: 1.55;
  color: var(--muted);
  margin: 0;
}

/* ---------- Prose ---------- */
.prose { color: var(--body); }
.prose h2 {
  font-size: 25px;
  letter-spacing: -0.015em;
  color: var(--ink);
  margin: 44px 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}
.prose h3 { font-size: 19px; color: var(--ink); margin: 30px 0 10px; }
.prose p, .prose ul, .prose ol { margin: 0 0 16px; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin: 6px 0; }
.prose strong { color: var(--ink); font-weight: 650; }
.prose a { font-weight: 500; }

.prose code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1.5px 5px;
}
.prose pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
  overflow-x: auto;
  font-size: 14px;
  line-height: 1.6;
  margin: 0 0 18px;
}
.prose pre code { background: none; border: 0; padding: 0; font-size: inherit; }

.prose blockquote {
  margin: 0 0 18px;
  padding: 12px 18px;
  background: var(--bg-soft);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  color: var(--body);
}
.prose blockquote p:last-child { margin: 0; }

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 20px;
  font-size: 15px;
}
.prose th, .prose td { text-align: left; padding: 9px 13px; border-bottom: 1px solid var(--border); }
.prose th { color: var(--ink); font-weight: 650; background: var(--bg-soft); }
.prose tr:last-child td { border-bottom: 0; }

.repo-link {
  margin-top: 38px;
  padding: 14px 18px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 14.5px;
  color: var(--muted);
}

/* ---------- Home ---------- */
.hero {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 44px;
  align-items: center;
  margin-bottom: 16px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--border);
}
.hero-copy h1 {
  font-size: 46px;
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--ink);
  margin: 0 0 16px;
}
.hero-copy .lead { font-size: 19.5px; color: var(--body); }
.hero-actions { margin-top: 26px; display: flex; gap: 12px; flex-wrap: wrap; }
.hero-figure {
  padding: 16px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 16px;
}
.hero-figure img { display: block; width: 100%; height: auto; }

.btn {
  display: inline-block;
  padding: 11px 20px;
  border-radius: 9px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--accent-deep); color: #fff; }
.btn-primary:hover { background: #1e40af; }
.btn-ghost { background: #fff; color: var(--ink); border-color: var(--border-strong); }
.btn-ghost:hover { background: var(--bg-soft); }

.briefing {
  margin: 36px auto;
  font-size: 18px;
  line-height: 1.65;
  color: var(--body);
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin: 8px auto 12px;
}
.cap {
  padding: 22px 22px 20px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 13px;
  transition: border-color .15s, box-shadow .15s;
}
.cap:hover { border-color: var(--border-strong); box-shadow: 0 6px 22px rgba(15,23,42,.05); }
.cap h3 { margin: 0 0 8px; font-size: 17px; color: var(--ink); letter-spacing: -0.01em; }
.cap p { margin: 0 0 12px; font-size: 14.5px; color: var(--body); }
.cap code { font-family: var(--mono); font-size: 0.84em; background: var(--code-bg); border-radius: 4px; padding: 1px 4px; }
.cap a { font-size: 14px; font-weight: 600; }

.band {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin: 34px auto 0;
  padding: 26px 30px;
  background: var(--ink);
  border-radius: 14px;
  color: #e2e8f0;
}
.band p { margin: 0; font-size: 16px; }
.band-kicker { font-size: 12.5px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; color: #93b4f5; margin-bottom: 6px; }
.band .btn-primary { background: #fff; color: var(--ink); white-space: nowrap; }
.band .btn-primary:hover { background: #e2e8f0; }

/* ---------- List / card grid ---------- */
.card-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.card {
  display: block;
  padding: 22px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 13px;
}
.card:hover { border-color: var(--border-strong); box-shadow: 0 6px 22px rgba(15,23,42,.05); text-decoration: none; }
.card-eyebrow { font-size: 12px; font-weight: 700; letter-spacing: .07em; text-transform: uppercase; color: var(--accent); margin-bottom: 8px; }
.card-title { font-size: 18px; font-weight: 650; color: var(--ink); margin-bottom: 6px; }
.card-desc { font-size: 14.5px; color: var(--muted); }

/* ---------- Footer ---------- */
.site-footer {
  margin-top: 64px;
  padding-top: 22px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
  font-size: 13.5px;
  color: var(--muted);
}
.site-footer a { color: var(--muted); }

/* ---------- Mobile ---------- */
.nav-toggle, .nav-burger { display: none; }
@media (max-width: 860px) {
  .layout { flex-direction: column; }
  .sidebar {
    position: static; height: auto; width: 100%; min-width: 0;
    border-right: 0; border-bottom: 1px solid var(--border);
  }
  .nav, .sidebar-foot { display: none; }
  .nav-toggle:checked ~ .layout .nav,
  .nav-toggle:checked ~ .layout .sidebar-foot { display: flex; }
  .nav-burger {
    display: inline-block; margin-bottom: 20px; cursor: pointer;
    font-size: 14px; font-weight: 600; color: var(--ink);
    padding: 8px 12px; border: 1px solid var(--border-strong); border-radius: 8px;
  }
  .content { padding: 28px 22px 60px; }
  .hero { grid-template-columns: 1fr; }
  .cards, .card-grid { grid-template-columns: 1fr; }
  .doc-head h1 { font-size: 30px; }
  .hero-copy h1 { font-size: 34px; }
  .band { flex-direction: column; align-items: flex-start; }
}