/* One reading column, a sticky top bar, and a side summary.
   Dark tokens are repeated under the system scheme and under data-theme
   so an explicit choice beats the system preference. */

:root {
  --bg: #f7f1e6;
  --ink: #241c14;
  --soft: #4e4338;
  --muted: #6b5c4c;
  --rule: #8d7360;
  --hair: #c3ae97;
  --link: #0c6b58;
  --link-visited: #6d3d62;
  --accent: #b8431f;
  --focus: #0b67c2;
  --bar-h: 3.4rem;
  --bar-bg: #1c3b34;
  --bar-ink: #f7f1e6;
  --bar-btn: #2d564c;
  --side-bg: #efe4d2;
  --side-active-bg: #1c3b34;
  --side-active-ink: #f7f1e6;
  --code-bg: #fffdf8;
  --code-ink: #241c14;
  --code-border: #c9b49a;
  --th-bg: #e7d8c2;
  --zebra: #fbf6ee;
  --def-bg: #e4f3ea;
  --def-bar: #1d7a4a;
  --def-tag: #145c36;
  --thm-bg: #f8ead0;
  --thm-bar: #b56a12;
  --thm-tag: #7a4308;
  --note-bg: #e6eef8;
  --note-bar: #2c5f99;
  --note-tag: #1b3f68;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #1b1612;
    --ink: #f4ecdf;
    --soft: #ddd1c0;
    --muted: #cbbba6;
    --rule: #cbbba6;
    --hair: #8d7b66;
    --link: #8fd0b8;
    --link-visited: #e0b4dc;
    --accent: #f0a06a;
    --focus: #ffd166;
    --bar-bg: #100e0c;
    --bar-ink: #f4ecdf;
    --bar-btn: #2c2622;
    --side-bg: #262019;
    --side-active-bg: #f0a06a;
    --side-active-ink: #1b1612;
    --code-bg: #262019;
    --code-ink: #f4ecdf;
    --code-border: #8d7b66;
    --th-bg: #312922;
    --zebra: #221c17;
    --def-bg: #173028;
    --def-bar: #7dcea0;
    --def-tag: #d5f5e3;
    --thm-bg: #3a2a14;
    --thm-bar: #f0c27a;
    --thm-tag: #fdebd0;
    --note-bg: #1c2a3d;
    --note-bar: #8eb4e0;
    --note-tag: #d6e6f8;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #1b1612;
  --ink: #f4ecdf;
  --soft: #ddd1c0;
  --muted: #cbbba6;
  --rule: #cbbba6;
  --hair: #8d7b66;
  --link: #8fd0b8;
  --link-visited: #e0b4dc;
  --accent: #f0a06a;
  --focus: #ffd166;
  --bar-bg: #100e0c;
  --bar-ink: #f4ecdf;
  --bar-btn: #2c2622;
  --side-bg: #262019;
  --side-active-bg: #f0a06a;
  --side-active-ink: #1b1612;
  --code-bg: #262019;
  --code-ink: #f4ecdf;
  --code-border: #8d7b66;
  --th-bg: #312922;
  --zebra: #221c17;
  --def-bg: #173028;
  --def-bar: #7dcea0;
  --def-tag: #d5f5e3;
  --thm-bg: #3a2a14;
  --thm-bar: #f0c27a;
  --thm-tag: #fdebd0;
  --note-bg: #1c2a3d;
  --note-bar: #8eb4e0;
  --note-tag: #d6e6f8;
  color-scheme: dark;
}

:root[data-theme="light"] {
  color-scheme: light;
}

@media (prefers-contrast: more) {
  :root,
  :root[data-theme="dark"],
  :root[data-theme="light"] {
    --bg: #ffffff;
    --ink: #000000;
    --soft: #111111;
    --muted: #222222;
    --rule: #000000;
    --hair: #000000;
    --link: #0000ee;
    --accent: #8a1c00;
    --bar-bg: #000000;
    --bar-ink: #ffffff;
    --side-bg: #ffffff;
    --side-active-bg: #000000;
    --side-active-ink: #ffffff;
    color-scheme: light;
  }
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--bar-h) + 0.8rem);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .sidetoc { transition: none; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Palatino, "Palatino Linotype", "Iowan Old Style", Georgia, serif;
  font-size: 1.125rem;
  line-height: 1.7;
  overflow-wrap: break-word;
}

a {
  color: var(--link);
  text-underline-offset: 0.16em;
}

a:visited { color: var(--link-visited); }

a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.skip {
  position: absolute;
  left: 0.6rem;
  top: 0.6rem;
  z-index: 50;
  transform: translateY(-200%);
  background: var(--bg);
  color: var(--ink);
  padding: 0.4rem 0.7rem;
  border: 2px solid var(--ink);
}

.skip:focus { transform: none; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  height: var(--bar-h);
  padding: 0 0.9rem;
  background: var(--bar-bg);
  color: var(--bar-ink);
  border-bottom: 3px solid var(--accent);
  font-family: "Segoe UI", system-ui, sans-serif;
}

.topbar a.brand {
  color: var(--bar-ink);
  font-weight: 750;
  text-decoration: none;
  white-space: nowrap;
}

.tb-title {
  flex: 1 1 auto;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 0.95rem;
}

.tb-btn {
  display: inline-flex;
  align-items: center;
  height: 2.3rem;
  padding: 0 0.75rem;
  border: 2px solid rgba(255, 255, 255, 0.75);
  border-radius: 0.4rem;
  background: var(--bar-btn);
  color: var(--bar-ink);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.tb-btn[hidden] { display: none; }

.layout { display: block; }

#mci-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.9rem;
  max-width: 40rem;
  margin: 0 auto;
  padding: 0.85rem 1.25rem 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  font-size: 0.92rem;
}

main#main {
  max-width: 40rem;
  margin: 0 auto;
  padding: 1.2rem 1.25rem 4rem;
}

h1, h2, h3, h4 { line-height: 1.25; scroll-margin-top: calc(var(--bar-h) + 0.6rem); }

h1 { font-size: 2.1rem; margin: 0.4rem 0 0.8rem; }

h2 {
  font-size: 1.55rem;
  margin: 2.6rem 0 0.8rem;
  padding-bottom: 0.25rem;
  border-bottom: 3px solid var(--accent);
}

h3 { font-size: 1.22rem; margin: 1.8rem 0 0.55rem; }

p { margin: 0.9rem 0; }

ul, ol { margin: 0.8rem 0; padding-left: 1.4rem; }

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: var(--code-bg);
  color: var(--code-ink);
  border: 1px solid var(--hair);
  border-radius: 0.25rem;
  padding: 0.05rem 0.28rem;
}

pre {
  background: var(--code-bg);
  color: var(--code-ink);
  border: 2px solid var(--code-border);
  border-radius: 0.4rem;
  padding: 0.85rem 1rem;
  overflow-x: auto;
}

pre code { border: 0; background: transparent; padding: 0; }

.tbl-wrap { overflow-x: auto; margin: 1rem 0; }

table { border-collapse: collapse; width: 100%; }

th, td {
  border: 1px solid var(--hair);
  padding: 0.4rem 0.55rem;
  text-align: left;
  vertical-align: top;
}

th { background: var(--th-bg); }

tbody tr:nth-child(even) { background: var(--zebra); }

blockquote {
  margin: 1rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  border-left: 4px solid var(--rule);
}

.def,
.thm,
.note {
  margin: 1.4rem 0;
  padding: 0.85rem 1rem 0.95rem;
  border: 2px solid transparent;
  border-left-width: 7px;
  border-radius: 0.35rem;
}

.def { background: var(--def-bg); border-color: var(--def-bar); }
.thm { background: var(--thm-bg); border-color: var(--thm-bar); }
.note { background: var(--note-bg); border-color: var(--note-bar); }

.def .tag,
.thm .tag,
.note .tag {
  display: block;
  margin-bottom: 0.35rem;
  font-family: "Segoe UI", system-ui, sans-serif;
  font-size: 0.92rem;
  font-weight: 750;
  font-style: normal;
}

.def .tag { color: var(--def-tag); }
.thm .tag { color: var(--thm-tag); }
.note .tag { color: var(--note-tag); }

.sidetoc {
  position: fixed;
  z-index: 28;
  top: 0;
  bottom: 0;
  left: 0;
  width: min(20rem, 86vw);
  overflow: auto;
  padding: 0.9rem 0.8rem 1.5rem;
  background: var(--side-bg);
  border-right: 3px solid var(--rule);
  font-family: "Segoe UI", system-ui, sans-serif;
  font-size: 0.95rem;
  line-height: 1.35;
  transform: translateX(-105%);
  visibility: hidden;
}

html.toc-open .sidetoc {
  transform: none;
  visibility: visible;
}

.toc-backdrop { display: none; }

html.toc-open .toc-backdrop {
  display: block;
  position: fixed;
  inset: 0;
  z-index: 27;
  background: rgba(20, 14, 8, 0.45);
}

.sidetoc-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.6rem;
}

.sidetoc-title {
  margin: 0;
  font-weight: 750;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.sidetoc-close {
  font: inherit;
  font-weight: 700;
  background: var(--bg);
  color: var(--ink);
  border: 2px solid var(--rule);
  border-radius: 0.35rem;
  padding: 0.25rem 0.55rem;
  cursor: pointer;
}

.sidetoc ol { list-style: none; margin: 0; padding: 0; }

.sidetoc a {
  display: block;
  color: var(--ink);
  text-decoration: none;
  padding: 0.32rem 0.5rem;
  border-left: 4px solid transparent;
  border-radius: 0.3rem;
}

.sidetoc li.lvl2 > a { font-weight: 700; }

.sidetoc-sub { display: none; margin-left: 0.7rem; }

.sidetoc li.open > .sidetoc-sub { display: block; }

.sidetoc a.active {
  background: var(--side-active-bg);
  color: var(--side-active-ink);
  border-left-color: var(--accent);
}

.sidetoc-top { margin-top: 0.9rem; font-weight: 700; }

@media (min-width: 70rem) {
  html.has-sidetoc .layout {
    display: grid;
    grid-template-columns: 16.5rem minmax(0, 1fr);
  }

  html.has-sidetoc .sidetoc {
    position: sticky;
    top: var(--bar-h);
    height: calc(100vh - var(--bar-h));
    width: auto;
    transform: none;
    visibility: visible;
  }

  html.has-sidetoc .sidetoc-close { display: none; }

  html.has-sidetoc.toc-hidden .layout { display: block; }

  html.has-sidetoc.toc-hidden .sidetoc { display: none; }
}

@media (max-width: 40rem) {
  .tb-label { display: none; }
  main#main { padding-left: 1rem; padding-right: 1rem; }
  h1 { font-size: 1.7rem; }
}

@media print {
  .topbar, .sidetoc, .toc-backdrop, .skip, #mci-nav { display: none !important; }
  main#main { max-width: none; }
}