:root {
  --paper: #faf7f2;
  --ink: #2a2b2f;
  --soft-ink: #3f444a;
  --muted: #6e7680;
  --muted-light: #8f969e;
  --line: #e4dfd6;
  --accent: #0f7a6c;
  --accent-soft: #e6f4f1;
  --code-bg: #f1eee7;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html { background: var(--paper); }

body {
  margin: 0 auto;
  padding: 40px 40px 72px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18.5px;
  line-height: 1.7;
  display: grid;
  grid-template-columns: minmax(220px, 300px) minmax(0, 760px);
  column-gap: 56px;
  align-items: start;
  justify-content: center;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body > nav#TOC {
  grid-column: 1;
  grid-row: 1 / span 999;
  width: 100%;
  max-height: calc(100vh - 64px);
  overflow: auto;
  position: sticky;
  top: 28px;
  padding: 4px 20px 24px 0;
  margin: 0;
  border-right: 1px solid var(--line);
  font-family: var(--sans);
  font-size: 14.5px;
  line-height: 1.35;
  scrollbar-width: thin;
  scrollbar-color: #cfc9bd transparent;
}

body > nav#TOC::before {
  content: "CONTENTS";
  display: block;
  margin: 0 0 12px 0;
  color: #56606b;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.18em;
}

nav#TOC ul {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

nav#TOC ul ul {
  padding-left: 14px;
}

nav#TOC a {
  color: var(--muted);
  display: block;
  padding: 3px 0 4px 12px;
  border-left: 3px solid transparent;
  text-decoration: none;
}

nav#TOC a:hover {
  color: var(--accent);
  border-left-color: var(--accent);
}

nav#TOC > ul > li > a {
  color: var(--soft-ink);
  font-weight: 650;
  margin-top: 8px;
}

body > :not(nav#TOC) {
  grid-column: 2;
  width: 100%;
  max-width: 760px;
  min-width: 0;
}

#title-block-header {
  margin: 0 0 40px;
}

h1, h2, h3, h4 {
  line-height: 1.15;
  font-family: var(--serif);
  color: #24252a;
}

h1.title {
  font-size: clamp(2.8rem, 6vw, 4.4rem);
  margin: 0 0 14px;
  font-weight: 800;
}

.subtitle {
  margin: 0 0 28px;
  color: #666c73;
  font-style: italic;
  font-size: 1.25rem;
  line-height: 1.35;
}

.author,
.date {
  display: inline-block;
  width: min(48%, 280px);
  margin: 0 0 4px;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.92rem;
  line-height: 1.4;
}

.author::before,
.date::before {
  display: block;
  margin-bottom: 4px;
  color: var(--muted-light);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.author::before { content: "AUTHOR"; }
.date::before { content: "UPDATED"; }

/* Category chapters (top-level after title) */
body > h1:not(.title) {
  font-size: 2.15rem;
  margin: 3.2rem 0 1rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
}

h2 {
  font-size: 1.55rem;
  margin: 2.2rem 0 0.85rem;
  color: #303238;
}

h3 {
  font-size: 1.2rem;
  margin-top: 1.6rem;
  color: #3a3d43;
}

p { margin: 0 0 1.2rem; }

a {
  color: var(--accent);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.12em;
}

a.handbook-link {
  font-family: var(--sans);
  font-weight: 650;
}

ul, ol {
  margin: 0 0 1.2rem;
  padding-left: 1.4rem;
}

li { margin: 0.25rem 0; }

blockquote {
  margin: 1.2rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  border-left: 4px solid var(--line);
  color: var(--soft-ink);
}

code {
  font-family: var(--mono);
  background: var(--code-bg);
  border-radius: 4px;
  padding: 0.05rem 0.28rem;
  font-size: 0.88em;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.95rem 1.05rem;
  overflow-x: auto;
  margin: 0 0 1.35rem;
  font-size: 0.86rem;
  line-height: 1.45;
}

pre code {
  background: transparent;
  padding: 0;
  font-size: inherit;
}

hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 2rem 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 1.35rem;
  font-size: 0.95rem;
}

th, td {
  border: 1px solid var(--line);
  padding: 0.45rem 0.65rem;
  text-align: left;
}

th {
  background: #f3efe7;
  font-family: var(--sans);
  font-size: 0.85rem;
}

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

@media (max-width: 960px) {
  body {
    padding: 22px 16px 48px;
    font-size: 17.5px;
    display: block;
    max-width: 760px;
  }

  body > nav#TOC {
    position: static;
    width: auto;
    max-height: none;
    border-right: none;
    border-bottom: 1px solid var(--line);
    margin: 0 0 22px;
    padding: 0 0 16px;
  }

  h1.title { font-size: 2.6rem; }
  body > h1:not(.title) { font-size: 1.85rem; }
}