/* Agentic platform + SlidWiki. Existing pages keep chrome.css. */
@import url("https://fonts.googleapis.com/css2?family=Source+Serif+4:opsz,wght@8..60,400;8..60,560&display=swap");

:root {
  --bg: #f6f5f2;
  --ink: #122033;
  --muted: #5c6570;
  --line: #ddd9d1;
  --accent: #0f6f73;
  --accent-ink: #f7f5f1;
  --warn: #9a7b2f;
  --band: #efece6;
  --navy: #0f1c2e;
  --max: 1120px;
  --measure: 68ch;
  --pad: 24px;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body.pf {
  margin: 0;
  overflow-x: clip;
  background: var(--bg);
  color: var(--ink);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.0625rem;
  line-height: 1.55;
  font-weight: 400;
}
a { color: inherit; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }

.pf-skip {
  position: absolute;
  left: 0.5rem;
  top: 0.5rem;
  transform: translateY(-150%);
  background: var(--ink);
  color: var(--bg);
  padding: 0.6rem 0.8rem;
  z-index: 20;
  font-family: system-ui, "Segoe UI", sans-serif;
}
.pf-skip:focus { transform: none; }

.pf-top {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.pf-bar {
  max-width: var(--max);
  margin: 0 auto;
  min-height: 56px;
  padding: 0 var(--pad);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.pf-brand {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--ink);
  text-decoration: none;
  font-family: system-ui, "Segoe UI", sans-serif;
  font-weight: 600;
  font-size: 15px;
  letter-spacing: 0.04em;
  min-height: 44px;
}
.pf-brand img {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 42%;
  display: block;
}
.pf-logo {
  width: min(280px, 72vw);
  height: auto;
  display: block;
  margin: 0 0 1.25rem;
  border-radius: 16px;
}
.pf-nav { display: flex; flex-wrap: wrap; gap: 0.15rem; margin-left: auto; font-family: system-ui, "Segoe UI", sans-serif; }
.pf-nav a, .pf-menu a {
  color: var(--ink);
  text-decoration: none;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0 0.7rem;
}
.pf-nav a[aria-current="page"] { box-shadow: inset 0 -2px 0 var(--accent); }
.pf-menu { display: none; margin-left: auto; font-family: system-ui, "Segoe UI", sans-serif; }
.pf-menu summary {
  list-style: none;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--ink);
  border-radius: 2px;
  background: var(--bg);
  cursor: pointer;
  padding: 0 0.8rem;
}
.pf-menu summary::-webkit-details-marker { display: none; }
.pf-menu[open] { position: relative; }
.pf-menu-panel {
  position: absolute;
  right: 0;
  top: calc(100% + 6px);
  background: var(--bg);
  border: 1px solid var(--ink);
  min-width: 14rem;
  padding: 0.25rem;
  display: flex;
  flex-direction: column;
}

.pf-wrap { max-width: var(--max); margin: 0 auto; padding: 0 var(--pad) 4rem; }
.pf-kicker {
  font-family: system-ui, "Segoe UI", sans-serif;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 0.5rem;
}
h1, h2, h3 {
  font-family: "Source Serif 4", Georgia, serif;
  font-weight: 560;
  letter-spacing: -0.02em;
}
h1 {
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  line-height: 1.08;
  max-width: 22ch;
  margin: 0 0 0.7rem;
}
h2 { font-size: 1.5rem; line-height: 1.2; margin: 0 0 0.55rem; scroll-margin-top: 72px; }
h3 { font-size: 1.2rem; line-height: 1.25; margin: 0 0 0.3rem; }
.pf-lede { color: var(--muted); max-width: 42ch; margin: 0 0 1rem; }
.pf-prose { max-width: var(--measure); }
.pf-prose p, .pf-prose li { max-width: var(--measure); }
code, .pf-mono {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  line-height: 1.4;
}
.pf-fact { color: var(--muted); font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace; font-size: 13px; font-variant-numeric: tabular-nums; }

.pf-actions { display: flex; flex-wrap: wrap; gap: 0.75rem 1.25rem; align-items: center; margin: 0.5rem 0 1.25rem; }
.pf-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 2px;
  text-decoration: none;
  font-family: system-ui, "Segoe UI", sans-serif;
  font-weight: 600;
}
.pf-btn-solid { background: var(--navy); color: var(--accent-ink); }
.pf-btn-line { color: var(--ink); text-decoration: underline; text-underline-offset: 3px; padding: 0; }

.pf-hero { padding: 48px 0 28px; }
.pf-lanes {
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--line);
  margin: 0.5rem 0 1.5rem;
}
.pf-lane { padding: 28px 0; border-bottom: 1px solid var(--line); }
.pf-lane p { max-width: 36ch; margin: 0.35rem 0 0.5rem; }
.pf-shelf {
  margin: 1.5rem 0;
  padding-top: 1rem;
  border-top: 1px solid var(--ink);
  box-shadow: inset 0 4px 0 var(--bg), inset 0 5px 0 var(--ink);
}
.pf-shelf h2 { margin-top: 0.8rem; }
.pf-engines { display: flex; flex-wrap: wrap; gap: 1rem 1.75rem; }
.pf-engines a { text-decoration: none; min-height: 44px; display: flex; flex-direction: column; justify-content: center; }
.pf-engines a span { color: var(--muted); font-size: 1rem; }

.pf-toc { margin: 0 0 1.25rem; font-family: system-ui, "Segoe UI", sans-serif; font-size: 0.95rem; }
.pf-toc ol { list-style: none; padding: 0; margin: 0; }
.pf-toc a {
  text-decoration: none;
  color: var(--muted);
  display: flex;
  align-items: center;
  min-height: 44px;
  padding-left: 0.7rem;
  border-left: 2px solid transparent;
}
.pf-toc a:hover { color: var(--ink); }
.pf-section {
  content-visibility: auto;
  contain-intrinsic-size: auto 480px;
  padding-top: 0.4rem;
  margin-top: 1.1rem;
  border-top: 1px solid var(--line);
}
.pf-note {
  border-left: 2px solid var(--accent);
  padding: 0.2rem 0 0.2rem 0.9rem;
  margin: 1rem 0;
  max-width: var(--measure);
}
.pf-warn { border-left-color: var(--warn); color: var(--warn); }
.pf-foot {
  border-top: 1px solid var(--line);
  padding: 1.25rem var(--pad) 2.5rem;
  max-width: var(--max);
  margin: 0 auto;
  color: var(--muted);
  font-family: system-ui, "Segoe UI", sans-serif;
  font-size: 0.95rem;
}
.pf-foot a { margin-right: 0.9rem; display: inline-flex; min-height: 44px; align-items: center; color: var(--ink); }
.pf-index { display: grid; gap: 1.75rem; }
.pf-index ul { list-style: none; padding: 0; margin: 0; }
.pf-index li { border-top: 1px solid var(--line); }
.pf-index a { display: flex; justify-content: space-between; gap: 1rem; min-height: 44px; align-items: center; text-decoration: none; padding: 0.35rem 0; }
.pf-index a span { color: var(--muted); }
table { width: 100%; border-collapse: collapse; font-size: 0.95rem; max-width: var(--measure); }
th, td { text-align: left; border-bottom: 1px solid var(--line); padding: 0.45rem 0.4rem; vertical-align: top; }

@media (min-width: 800px) {
  .pf-wrap { padding-left: 40px; padding-right: 40px; }
  .pf-bar { padding-left: 40px; padding-right: 40px; }
  .pf-hero { padding-top: 80px; }
  .pf-lanes { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .pf-lane { padding: 28px 24px; border-bottom: 0; border-right: 1px solid var(--line); }
  .pf-lane:last-child { border-right: 0; }
}
@media (max-width: 799px) {
  .pf-nav { display: none; }
  .pf-menu { display: block; }
}
@media (min-width: 960px) {
  .pf-layout {
    display: grid;
    grid-template-columns: 200px minmax(0, 68ch) minmax(0, 1fr);
    gap: 1.5rem;
    align-items: start;
  }
  .pf-toc {
    position: sticky;
    top: 24px;
    align-self: start;
    max-height: calc(100vh - 48px);
    overflow: auto;
  }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}