:root {
  color-scheme: light;
  --bg: #f6f1e8;
  --paper: #fbf7f0;
  --ink: #1c1916;
  --muted: #5c564e;
  --rule: #d7cfc2;
  --link: #8a3b12;
  --code-bg: #efe8dc;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font: 18px/1.55 Georgia, "Times New Roman", serif;
}

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

code, pre, kbd, samp {
  font-family: Menlo, Monaco, Consolas, monospace;
  font-size: 0.84em;
}

code {
  background: var(--code-bg);
  padding: 0.1em 0.35em;
}

pre {
  background: var(--code-bg);
  padding: 0.9rem 1rem;
  overflow-x: auto;
  white-space: pre-wrap;
  word-wrap: break-word;
  line-height: 1.4;
}

pre code {
  background: none;
  padding: 0;
  font-size: 1em;
}

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

table {
  border-collapse: collapse;
  max-width: 100%;
  font-size: 0.95rem;
  margin: 0 0 1rem;
}

th, td {
  border: 1px solid var(--rule);
  padding: 0.25em 0.5em;
  vertical-align: top;
}

blockquote {
  margin: 0 0 1rem;
  padding-left: 1rem;
  border-left: 3px solid var(--rule);
  color: var(--muted);
}

/* Home */

body.home main {
  max-width: 36rem;
  margin: 0 auto;
  padding: 3.5rem 1.25rem 4rem;
}

body.home h1 {
  font-size: 2rem;
  font-weight: normal;
  letter-spacing: 0.01em;
  margin: 0 0 0.35rem;
}

.byline {
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0 0 1.75rem;
}

.cover {
  display: block;
  width: min(100%, 18rem);
  margin: 0 0 1.75rem;
  border: 1px solid var(--rule);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 0.75rem;
  margin: 1.5rem 0 2rem;
}

.actions a {
  display: inline-block;
  padding: 0.45rem 0.9rem;
  border: 1px solid var(--ink);
  color: var(--ink);
  text-decoration: none;
  font-size: 0.95rem;
}

.actions a:hover,
.actions a.primary {
  background: var(--ink);
  color: var(--bg);
}

.actions a.primary:hover {
  background: var(--link);
  border-color: var(--link);
}

.chapter-list {
  list-style: none;
  padding: 0;
  margin: 0 0 2rem;
}

.chapter-list li {
  margin: 0;
  border-top: 1px solid var(--rule);
}

.chapter-list a {
  display: flex;
  gap: 0.75rem;
  padding: 0.55rem 0;
  text-decoration: none;
  color: var(--ink);
}

.chapter-list a:hover { color: var(--link); }

.chapter-list .n {
  color: var(--muted);
  min-width: 1.5rem;
}

body.home footer {
  margin-top: 2.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.95rem;
}

body.home footer a { color: var(--muted); }

body.home p { margin: 0 0 1rem; }

/* Book reader */

body.book {
  min-height: 100vh;
}

body.book .site {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 1rem;
  border-bottom: 1px solid var(--rule);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 3;
}

body.book .brand {
  color: var(--ink);
  text-decoration: none;
  font-size: 1rem;
  margin-right: auto;
}

body.book .brand:hover { color: var(--link); }

body.book .site-links {
  display: flex;
  gap: 0.9rem;
  font-size: 0.9rem;
}

#toc-toggle {
  font: inherit;
  font-size: 0.9rem;
  background: var(--bg);
  color: var(--ink);
  border: 1px solid var(--ink);
  padding: 0.25rem 0.6rem;
  cursor: pointer;
}

.layout {
  display: block;
}

#TOC {
  display: none;
  background: var(--paper);
  border-right: 1px solid var(--rule);
  padding: 1rem 1rem 2rem;
}

body.toc-open #TOC { display: block; }

#TOC h2 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: normal;
  color: var(--muted);
  margin: 0 0 0.75rem;
}

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

#TOC li { margin: 0; }

#TOC > ul > li > a {
  display: block;
  padding: 0.35rem 0 0.15rem;
  color: var(--ink);
  text-decoration: none;
  font-size: 0.95rem;
}

#TOC ul ul {
  padding-left: 0.85rem;
  margin-bottom: 0.45rem;
}

#TOC ul ul a {
  display: block;
  padding: 0.12rem 0;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.88rem;
}

#TOC a:hover { color: var(--link); }
#TOC a.current { color: var(--link); font-style: italic; }

.main {
  max-width: 42rem;
  margin: 0 auto;
  padding: 1.25rem 1.25rem 4rem;
}

.main h1, .main h2, .main h3, .main h4, .main h5, .main h6 {
  line-height: 1.25;
  page-break-after: avoid;
  position: relative;
  padding-right: 1.5rem;
  scroll-margin-top: 4rem;
}

.main h1:target, .main h2:target, .main h3:target,
.main h4:target, .main h5:target, .main h6:target {
  background: color-mix(in srgb, var(--link) 10%, transparent);
}

.header-anchor {
  position: absolute;
  right: 0;
  top: 0;
  color: var(--muted);
  text-decoration: none;
  font-weight: normal;
  font-size: 0.85em;
  line-height: inherit;
  opacity: 0;
  padding: 0 0.15rem;
}

.main h1:hover .header-anchor,
.main h2:hover .header-anchor,
.main h3:hover .header-anchor,
.main h4:hover .header-anchor,
.main h5:hover .header-anchor,
.main h6:hover .header-anchor,
.header-anchor:focus,
.header-anchor:hover {
  opacity: 1;
}

@media (hover: none) {
  .header-anchor { opacity: 0.4; }
}

.main h1 {
  font-size: 1.85rem;
  font-weight: normal;
  margin: 0 0 0.8rem;
}

.main h2 {
  font-size: 1.35rem;
  font-weight: normal;
  margin: 1.8rem 0 0.6rem;
}

.main p { margin: 0 0 1rem; }

#title-block-header {
  margin-bottom: 1.5rem;
}

#title-block-header .title {
  font-size: 2rem;
  font-weight: normal;
  margin: 0 0 0.35rem;
}

#title-block-header .author {
  color: var(--muted);
  margin: 0 0 1rem;
}

.abstract {
  color: var(--muted);
  font-size: 1rem;
}

.abstract-title {
  font-style: italic;
  margin-bottom: 0.4rem;
}

.pager {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.9rem;
  margin: 0 0 1.5rem;
}

.pager-bottom {
  margin: 2.5rem 0 0;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
}

.pager a {
  text-decoration: none;
  max-width: 45%;
}

.pager-next { text-align: right; margin-left: auto; }

.pager a::before { color: var(--muted); }

.pager-prev[href]::before { content: "← "; }
.pager-next[href]::after { content: " →"; }

@media (min-width: 880px) {
  #toc-toggle { display: none; }

  .layout {
    display: grid;
    grid-template-columns: minmax(14rem, 20rem) 1fr;
    align-items: start;
  }

  #TOC {
    display: block;
    position: sticky;
    top: 3.1rem;
    height: calc(100vh - 3.1rem);
    overflow: auto;
  }

  body.toc-open #TOC { display: block; }

  .main {
    padding-top: 1.75rem;
  }
}