:root {
  color-scheme: light;
  --bg: #f7f3ec;
  --paper: #fffdf9;
  --ink: #1c1915;
  --muted: #5f584e;
  --line: #e3dbcf;
  --accent: #24574a;
  --accent-soft: #e7f0ec;
  --mark: #f4e6c4;
  --sidebar: #f1ebe2;
  --shadow: 0 1px 0 rgba(28, 25, 21, 0.04);
  --sans: "Iowan Old Style", Palatino, "Palatino Linotype", Georgia, "Times New Roman", serif;
  --ui: "Avenir Next", "Segoe UI", sans-serif;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #161513;
  --paper: #201e1b;
  --ink: #f4efe6;
  --muted: #b7aea0;
  --line: #3a342c;
  --accent: #8fcebb;
  --accent-soft: #24312d;
  --mark: #4a3d22;
  --sidebar: #1b1916;
  --shadow: none;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #161513;
    --paper: #201e1b;
    --ink: #f4efe6;
    --muted: #b7aea0;
    --line: #3a342c;
    --accent: #8fcebb;
    --accent-soft: #24312d;
    --mark: #4a3d22;
    --sidebar: #1b1916;
    --shadow: none;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.125rem;
  line-height: 1.6;
}

a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }

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

.skip {
  position: absolute;
  left: -999px;
  top: 0;
}
.skip:focus { left: 1rem; background: var(--paper); padding: 0.4rem 0.6rem; z-index: 5; }

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 1.25rem;
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 4;
}

.brand {
  color: inherit;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.brand small {
  display: block;
  font-weight: 400;
  color: var(--muted);
  font-size: 0.82rem;
  font-family: var(--ui);
}

.top-tools {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex: 1;
  justify-content: flex-end;
}

.search { position: relative; width: min(22rem, 100%); }
.search input {
  width: 100%;
  font: inherit;
  font-size: 1rem;
  padding: 0.4rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--bg);
  color: var(--ink);
}
.search-results {
  position: absolute;
  right: 0;
  top: calc(100% + 0.35rem);
  width: min(28rem, 80vw);
  max-height: 22rem;
  overflow: auto;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 0.6rem;
  box-shadow: var(--shadow);
  padding: 0.35rem;
}
.search-results a {
  display: block;
  color: inherit;
  text-decoration: none;
  padding: 0.45rem 0.55rem;
  border-radius: 0.4rem;
}
.search-results a:hover { background: var(--accent-soft); }
.search-results .hit-title { font-weight: 700; }
.search-results .hit-meta, .search-results .hit-snip {
  display: block;
  color: var(--muted);
  font-size: 0.88rem;
  font-family: var(--ui);
}
.search-results mark { background: var(--mark); color: inherit; }

.theme {
  font-family: var(--ui);
  font-size: 0.85rem;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
  border-radius: 999px;
  padding: 0.35rem 0.7rem;
  cursor: pointer;
}

.shell {
  display: grid;
  grid-template-columns: 17.5rem minmax(0, 1fr);
  min-height: calc(100vh - 4.2rem);
}

.sidebar-drawer { background: var(--sidebar); border-right: 1px solid var(--line); }
.menu-toggle {
  display: none;
  font-family: var(--ui);
  font-size: 0.85rem;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
  border-radius: 999px;
  padding: 0.35rem 0.7rem;
  cursor: pointer;
}
.sidebar {
  padding: 0.8rem 0.75rem 2rem;
  position: sticky;
  top: 4.2rem;
  max-height: calc(100vh - 4.2rem);
  overflow: auto;
}
.sidebar a { color: inherit; text-decoration: none; }
.sidebar a:hover { color: var(--accent); }
.sidebar .nav-home {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  margin-bottom: 0.6rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--line);
}
.sidebar .nav-home a, .sidebar .topic a, .sidebar summary a {
  display: block;
  padding: 0.2rem 0.45rem;
  border-radius: 0.35rem;
}
.sidebar a[aria-current="page"] {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
}
.sidebar details { margin: 0.15rem 0; }
.sidebar summary {
  cursor: pointer;
  font-family: var(--ui);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 0.25rem 0.2rem;
}
.sidebar summary a {
  display: inline;
  padding: 0;
  text-transform: none;
  letter-spacing: 0;
  font-family: var(--sans);
  font-size: 1.02rem;
  color: var(--ink);
  font-weight: 700;
}
.sidebar ul { list-style: none; margin: 0.15rem 0 0.4rem; padding: 0 0 0 0.45rem; }
.sidebar .group {
  margin: 0.2rem 0 0.35rem 0.35rem;
  border-left: 2px solid var(--line);
  padding-left: 0.15rem;
}
.sidebar .group > summary { text-transform: none; letter-spacing: 0; font-size: 1rem; font-family: var(--sans); color: var(--ink); }

.main { padding: 1.5rem 1.6rem 3rem; max-width: 52rem; }
.crumbs {
  font-family: var(--ui);
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0 0 0.8rem;
}
.crumbs a { color: var(--muted); }

h1 { font-size: 2rem; line-height: 1.2; margin: 0 0 0.8rem; letter-spacing: -0.02em; }
h2 { font-size: 1.4rem; line-height: 1.3; margin: 1.4rem 0 0.5rem; }
h3 { font-size: 1.15rem; margin: 1.2rem 0 0.4rem; }

.prose { max-width: 68ch; }
.prose p, .prose li { hanging-punctuation: first; }
.prose blockquote {
  margin: 1rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  border-left: 3px solid var(--accent);
  color: var(--ink);
}
.prose pre, .prose code {
  font-family: "Iowan Old Style", ui-monospace, monospace;
  font-size: 0.95rem;
}
.prose pre {
  background: var(--accent-soft);
  padding: 0.8rem 1rem;
  overflow: auto;
  border-radius: 0.4rem;
  white-space: pre-wrap;
}
.prose table { border-collapse: collapse; width: 100%; font-size: 0.95rem; }
.prose th, .prose td { border-bottom: 1px solid var(--line); text-align: left; padding: 0.4rem 0.5rem; vertical-align: top; }
.hero, .prose img { border-radius: 0.35rem; }
.video, iframe.video {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
  border-radius: 0.4rem;
  background: #000;
}

.era { margin: 0 0 1rem; }
.era-current {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 0.7rem;
  padding: 1rem 1.1rem 1.2rem;
}
.era-kicker {
  font-family: var(--ui);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0;
}
.era-head { display: block; min-width: 0; }
.era-name {
  display: block;
  margin: 0.15rem 0 0;
  font-weight: 700;
  line-height: 1.3;
}
.era-current .era-name { font-size: 1.45rem; }
details.era .era-name { font-size: 1.05rem; }
.era-sub {
  display: block;
  margin: 0.15rem 0 0;
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 400;
  line-height: 1.4;
}
.era-meta, .source {
  font-family: var(--ui);
  font-size: 0.82rem;
  color: var(--muted);
}
details.era {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 0.7rem;
  padding: 0.55rem 1rem 0.3rem;
}
details.era[open] { padding-bottom: 1rem; }
details.era > summary {
  cursor: pointer;
  font-weight: 400;
  line-height: 1.35;
}
details.era > summary .when { color: var(--accent); font-weight: 650; }
.permalink { font-family: var(--ui); font-size: 0.85rem; }

.card-list { list-style: none; padding: 0; }
.card-list li { margin: 0 0 0.7rem; }
.card-list a { font-weight: 700; text-decoration: none; }
.card-list a:hover { text-decoration: underline; }
.card-list p { margin: 0.15rem 0 0; color: var(--muted); }

.thinking { margin-top: 2rem; }
.thinking h2 { margin-bottom: 0.35rem; }
.thinking-intro { font-size: 1.2rem; margin: 0 0 0.85rem; }
.thinking table { width: 100%; border-collapse: collapse; background: var(--paper); }
.thinking th, .thinking td {
  padding: 0.7rem 0.75rem;
  vertical-align: top;
  text-align: left;
}
.thinking thead th {
  text-align: center;
  font-size: 1.05rem;
  border-bottom: 2px solid var(--ink);
}
.thinking tbody th {
  font-weight: 700;
  width: 8.5rem;
}
.thinking tbody th a { color: inherit; }
.thinking tbody tr + tr th,
.thinking tbody tr + tr td { border-top: 1px solid var(--line); }
.thinking td p, .thinking th p { margin: 0; }

.coming {
  font-family: var(--ui);
  color: var(--muted);
  border-top: 1px solid var(--line);
  padding-top: 0.8rem;
}

.page-list { list-style: none; padding: 0; }
.page-list li { margin: 0.8rem 0; }
.page-list a { font-weight: 700; font-size: 1.15rem; }

footer.site {
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-family: var(--ui);
  font-size: 0.85rem;
  padding: 1rem 1.5rem 2rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

@media (max-width: 859px) {
  .shell { grid-template-columns: 1fr; }
  .menu-toggle { display: inline-block; }
  .sidebar-drawer { display: none; }
  .sidebar-drawer.is-open { display: block; }
  .sidebar { position: static; max-height: none; }
  .topbar { flex-wrap: wrap; }
  .top-tools { width: 100%; }
  .search { width: 100%; }
  .main { padding: 1.1rem 1rem 2.5rem; }
  h1 { font-size: 1.7rem; }
  .thinking thead { display: none; }
  .thinking table, .thinking tbody, .thinking tr, .thinking th, .thinking td { display: block; width: auto; }
  .thinking tr {
    padding: 0.35rem 0 0.8rem;
    border-bottom: 1px solid var(--line);
  }
  .thinking tbody tr + tr th,
  .thinking tbody tr + tr td { border-top: 0; }
  .thinking tbody th { font-size: 1.2rem; padding-bottom: 0.15rem; }
  .thinking td { padding: 0.35rem 0.75rem; }
  .thinking td::before {
    content: attr(data-label);
    display: block;
    font-family: var(--ui);
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    color: var(--muted);
  }
}