/* The atfq book in the devutils art direction. Replaces the book.css that
   atfq's `cargo run --example book` writes (scripts/atfq-book.mjs copies it
   over); the class names are that generator's, so keep them in step.
   Dark only: the generator's theme toggle is hidden. */

:root {
  color-scheme: dark;
  --bg: #050507;
  --surface: #ffffff06;
  --side: #07080ccc;
  --line: #ffffff16;
  --glass-line: #ffffff17;
  --fg: #f0f0f5;
  --muted: #a3a5b6;
  --accent: #82e9ff;
  --magenta: #b7a0ff;
  --green: #9fe8c2;
  --yellow: #f2d58a;
  --key-bg: #ffffff0d;
  --hl: #82e9ff14;

  --t-bg: #08090ccc;
  --t-line: #ffffff14;
  --t-fg: #c9ccd8;
  --t-dim: #8e92a6;
  --t-cyan: #82e9ff;
  --t-yellow: #f2d58a;
  --t-bright: #f0f0f5;

  --display: Inter, Arial, Helvetica, sans-serif;
  --body: Inter, Arial, Helvetica, sans-serif;
  --mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;

  --radius: 16px;
  --side-w: 19rem;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 4.5rem; }
body {
  margin: 0;
  color: var(--fg);
  font: 400 1rem/1.75 var(--body);
  -webkit-font-smoothing: antialiased;
  background:
    radial-gradient(60rem 40rem at 85% -10%, #82e9ff12, #0000 60%),
    radial-gradient(50rem 40rem at 10% 110%, #b7a0ff14, #0000 60%),
    var(--bg);
  background-attachment: fixed;
}
a { color: var(--accent); text-underline-offset: 3px; }
a:focus-visible, button:focus-visible, summary:focus-visible, input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}
code, pre, kbd { font-family: var(--mono); }
code { font-size: 0.88em; color: #bbc5e4; overflow-wrap: anywhere; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 1rem; top: 1rem; z-index: 10; background: #fff; color: #000; padding: 0.5rem 1rem; }

/* frosted glass, as on the devutils pages */
.sidebar, .bar, .search input, .results, .tldr, details, .card-list a, .parts a,
.pager a, .install, .machine .term {
  backdrop-filter: blur(20px) saturate(150%);
}

/* ----- sidebar ----- */
.sidebar {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--side-w);
  overflow-y: auto;
  overscroll-behavior: contain;
  background: var(--side);
  border-right: 1px solid var(--line);
  padding: 1.25rem 0.75rem 3rem;
  font-size: 0.9rem;
  line-height: 1.45;
  transition: transform 0.25s ease;
  z-index: 3;
}
.toc, .toc ol { list-style: none; margin: 0; padding: 0; }
.toc ol { display: none; margin: 0.15rem 0 0.4rem 1.4rem; border-left: 1px solid var(--line); }
.toc .open > ol { display: block; }
.toc li.ch { position: relative; }
.toc a {
  display: block;
  padding: 0.35rem 2rem 0.35rem 0.7rem;
  color: #d6d8e6;
  text-decoration: none;
  border-radius: 10px;
  transition: background 0.2s, color 0.2s;
}
.toc ol a { padding: 0.28rem 0.7rem; color: var(--muted); font-size: 0.86rem; }
.toc a b { font: 400 0.8em/1 var(--mono); color: var(--muted); margin-right: 0.3rem; }
.toc a:hover { color: #fff; background: #ffffff08; }
.toc a.active { background: var(--hl); color: var(--accent); box-shadow: inset 0 0 0 1px #82e9ff26; }
.toc a.active b { color: var(--accent); }
.toc .part {
  font: 400 0.68rem/1 var(--mono);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #a9abbb;
  padding: 1.6rem 0.7rem 0.6rem;
}
.fold {
  position: absolute;
  right: 0.2rem;
  top: 0.2rem;
  width: 1.7rem;
  height: 1.7rem;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}
.fold::before { content: "▸"; font-size: 0.8rem; display: inline-block; transition: transform 0.2s; }
.open > .fold::before { transform: rotate(90deg); }
.fold:hover { color: var(--accent); background: var(--hl); }

/* ----- page frame ----- */
.page { margin-left: var(--side-w); min-height: 100vh; transition: margin 0.25s ease; }
.sidebar-hidden .sidebar { transform: translateX(-100%); }
.sidebar-hidden .page { margin-left: 0; }

.bar {
  position: sticky;
  top: 0;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  height: 3.6rem;
  padding: 0 max(16px, env(safe-area-inset-right, 0px)) 0 0.75rem;
  background: #05050759;
  border-bottom: 1px solid var(--line);
}
.icon {
  border: 0;
  background: transparent;
  color: var(--muted);
  font: 400 1.05rem/1 var(--mono);
  min-width: 2.3rem;
  height: 2.3rem;
  border-radius: 999px;
  cursor: pointer;
  display: inline-grid;
  place-items: center;
  text-decoration: none;
  transition: background 0.2s, color 0.2s;
}
.icon:hover { color: #fff; background: #ffffff0d; }
#toggle-theme { display: none; } /* dark only */
.icon.gh { margin-left: auto; }
.bar a.icon { font: 400 0.8rem/1 var(--body); padding: 0 0.8rem; border: 1px solid var(--glass-line); background: #ffffff0a; height: 2.1rem; margin-left: 0.4rem; }
.bar a.icon.gh { margin-left: auto; }
/* the breadcrumb scripts/atfq-book.mjs puts in place of the title */
.book-title {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font: 600 1rem/1 var(--display);
  letter-spacing: -0.4px;
  color: var(--fg);
  text-decoration: none;
  white-space: nowrap;
}
.book-title img { width: 22px; height: 22px; filter: drop-shadow(0 0 10px #a7b6ff55); }
.book-title .sep { color: #494951; font-weight: 400; }
.book-title .dim { color: var(--muted); font-weight: 500; }

/* ----- search ----- */
.search {
  position: sticky;
  top: 3.9rem;
  z-index: 2;
  max-width: 48rem;
  margin: 0 auto;
  padding: 0.75rem 16px 0;
}
.search input {
  width: 100%;
  font: 400 0.95rem/1.4 var(--mono);
  padding: 0.85rem 1.2rem;
  color: var(--fg);
  background: #0a0b10cc;
  border: 1px solid #b7a0ff55;
  border-radius: 999px;
  outline: none;
  box-shadow: 0 0 0 4px #b7a0ff10, 0 20px 50px -25px #000;
}
.results {
  list-style: none;
  margin: 0.5rem 0 0;
  padding: 0.3rem;
  background: #0a0b10e6;
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  max-height: min(60vh, 32rem);
  overflow-y: auto;
  box-shadow: 0 30px 60px -30px #000;
}
.results:empty { display: none; }
.results a {
  display: grid;
  grid-template-columns: 3.4rem minmax(0, 1fr);
  gap: 0 0.75rem;
  padding: 0.65rem 0.9rem;
  color: var(--fg);
  text-decoration: none;
  border-radius: 12px;
}
.results a b { font: 400 0.8rem/1.7 var(--mono); color: var(--magenta); grid-row: span 2; }
.results a small { color: var(--muted); font-size: 0.85rem; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.results a.sel, .results a:hover { background: #ffffff0a; }
.results mark { background: none; color: var(--magenta); font-weight: 600; }
.results .none { padding: 0.75rem 1rem; color: var(--muted); }

/* ----- content ----- */
.content {
  max-width: 46rem;
  margin: 0 auto;
  padding: 3rem max(16px, env(safe-area-inset-right, 0px)) 4rem max(16px, env(safe-area-inset-left, 0px));
}
.eyebrow {
  font: 400 0.7rem/1.6 var(--mono);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: #a9abbb;
  margin: 0 0 1.1rem;
}
h1 {
  font: 500 clamp(2rem, 4.4vw, 2.9rem)/1.1 var(--display);
  letter-spacing: -0.045em;
  margin: 0 0 1.1rem;
  text-wrap: balance;
}
h1 .num {
  margin-right: 0.2em;
  color: #0000;
  background: linear-gradient(110deg, #82e9ff, #b7a0ff) text;
  -webkit-background-clip: text;
}
h1.hero { font-size: clamp(2.4rem, 6vw, 3.6rem); line-height: 1.04; letter-spacing: -0.055em; font-weight: 600; }
h1 .q { color: #0000; background: linear-gradient(110deg, #b5c9ff, #b78de6) text; -webkit-background-clip: text; }
h2 {
  font: 500 1.3rem/1.3 var(--display);
  letter-spacing: -0.03em;
  margin: 3rem 0 1rem;
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}
h2 small { font: 400 0.72rem/1 var(--mono); color: var(--muted); letter-spacing: 0.04em; }
.content p, .content li { overflow-wrap: break-word; }
.content p { color: #d6d8e6; }
.content ul, .content ol:not([class]) { padding-left: 1.3rem; }
.content li { margin: 0.35rem 0; color: #d6d8e6; }
.content li::marker { color: var(--accent); }
strong { font-weight: 600; color: #fff; }
.kind {
  display: inline-block;
  font: 400 0.7rem/1 var(--mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #c1b5ff;
  background: #a89aff0a;
  border: 1px solid #bcb1ff35;
  border-radius: 999px;
  padding: 0.35rem 0.75rem;
  margin: 0 0 0.75rem;
}
.lede { font-size: 1.1rem; color: var(--muted) !important; }
.lede strong { color: var(--fg); font-weight: 500; }

.aliases { display: flex; flex-wrap: wrap; gap: 0.4rem; align-items: center; margin: -0.25rem 0 1.75rem; }
.aliases span { font: 400 0.75rem/1 var(--mono); color: var(--muted); margin-right: 0.2rem; }
.aliases code {
  font-size: 0.76rem;
  color: #c6c8d8;
  background: #ffffff08;
  border: 1px solid var(--glass-line);
  border-radius: 999px;
  padding: 0.2rem 0.6rem;
}

.tldr {
  background: linear-gradient(135deg, #82e9ff0d, #ffffff03 55%), #0a0b1033;
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  box-shadow: inset 0 1px 0 #ffffff1c, inset 3px 0 0 #82e9ff99;
  padding: 0.25rem 1.5rem 1rem;
}
.tldr h2 { margin-top: 1.1rem; color: var(--accent); }

pre.code, .term pre {
  margin: 1.1rem 0;
  padding: 1rem 1.2rem;
  background: var(--t-bg);
  border: 1px solid var(--t-line);
  color: var(--t-fg);
  border-radius: 12px;
  font-size: 0.84rem;
  line-height: 1.65;
  overflow-x: auto;
}
pre.code code { color: inherit; font-size: inherit; overflow-wrap: normal; }
pre.code .danger { color: var(--t-yellow); }
pre.code .danger::before { content: "⚠ "; }
code.danger { color: var(--yellow); }

.machine .term {
  margin: 1.1rem 0 0.5rem;
  background: var(--t-bg);
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  box-shadow: inset 0 1px 0 #ffffff14;
  overflow: hidden;
}
.term-bar {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.6rem 1.1rem;
  border-bottom: 1px solid var(--t-line);
  font: 400 0.75rem/1.4 var(--mono);
  color: var(--t-dim);
}
.term-bar span:last-child {
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--t-yellow);
}
.machine .term pre { margin: 0; border: 0; border-radius: 0; background: none; font-size: 0.8rem; }
.c { color: var(--t-cyan); }
.d { color: var(--t-dim); }
.b { color: var(--t-bright); font-weight: 600; }
.e { font-style: italic; }
.y { color: var(--t-yellow); }
a.ref { font: 400 0.88em/1 var(--mono); text-decoration: none; border-bottom: 1px solid #82e9ff66; }
a.ref:hover { border-bottom-color: var(--accent); }
.meta a code { text-decoration: underline; text-underline-offset: 3px; }
.note { font-size: 0.85rem; color: var(--muted) !important; margin: 0; }

.dive { display: grid; gap: 0.6rem; }
details {
  background: linear-gradient(135deg, #ffffff0a, #ffffff02 55%), #0a0b1033;
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  box-shadow: inset 0 1px 0 #ffffff14;
}
summary {
  cursor: pointer;
  padding: 0.9rem 1.1rem 0.9rem 2.6rem;
  font-weight: 500;
  list-style: none;
  position: relative;
}
summary::-webkit-details-marker { display: none; }
summary::before {
  content: "▸";
  position: absolute;
  left: 1.1rem;
  color: var(--accent);
  transition: transform 0.2s;
}
details[open] > summary::before { transform: rotate(90deg); }
details[open] > summary { border-bottom: 1px solid var(--line); }
details > div { padding: 0.25rem 1.4rem 0.9rem 2.6rem; }

.rows, .meta { margin: 0; }
.rows div, .meta div {
  display: grid;
  grid-template-columns: minmax(0, 15rem) minmax(0, 1fr);
  gap: 0.25rem 1.25rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--line);
}
.rows dd, .meta dd { margin: 0; color: var(--muted); }
.meta { margin-top: 3rem; padding-top: 1.1rem; border-top: 1px solid var(--line); font-size: 0.92rem; }
.meta div { grid-template-columns: 7rem minmax(0, 1fr); border: 0; padding: 0.3rem 0; }
.meta dt { font: 400 0.7rem/2 var(--mono); text-transform: uppercase; letter-spacing: 0.1em; color: #a9abbb; }
.meta code { margin-right: 0.4rem; }

.card-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.6rem; }
.card-list a, .parts a {
  display: grid;
  grid-template-columns: 3.2rem minmax(0, 1fr);
  gap: 0.1rem 0.75rem;
  padding: 0.95rem 1.15rem;
  background: linear-gradient(135deg, #ffffff0a, #ffffff02 55%), #0a0b1033;
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  box-shadow: inset 0 1px 0 #ffffff14;
  color: var(--fg);
  text-decoration: none;
  transition: border-color 0.25s;
}
.card-list a:hover, .parts a:hover { border-color: #a3b6ff55; }
.card-list b { font: 400 0.82rem/1.75 var(--mono); color: var(--accent); grid-row: span 2; }
.card-list span { font-weight: 500; }
.card-list small { color: var(--muted); font-size: 0.88rem; }

/* introduction */
.install {
  display: flex;
  border: 1px solid var(--glass-line);
  border-radius: 999px;
  background: #ffffff08;
  overflow: hidden;
  margin: 1.5rem 0;
}
.install pre { margin: 0; padding: 0.8rem 1.3rem; overflow-x: auto; flex: 1; min-width: 0; font-size: 0.85rem; color: #c9ccd8; }
.install .p { color: #8a8ca0; user-select: none; }
.copy {
  border: 0;
  border-left: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  font: 400 0.75rem/1 var(--body);
  padding: 0 1.2rem;
  cursor: pointer;
}
.copy:hover { color: #fff; }
.stats { display: flex; flex-wrap: wrap; gap: 0.5rem 2.2rem; list-style: none; padding: 0; margin: 1.75rem 0 0; font: 400 0.8rem/1.4 var(--mono); color: var(--muted); }
.stats b { font: 500 1.6rem/1 var(--display); letter-spacing: -0.04em; color: var(--fg); margin-right: 0.4rem; }
.parts { list-style: none; padding: 0; display: grid; gap: 0.6rem; }
.parts a { grid-template-columns: 2.5rem minmax(0, 1fr); }
.parts .roman { font: 500 1.15rem/1.5 var(--display); color: var(--accent); grid-row: span 2; }
.parts small { color: var(--muted); font: 400 0.78rem/1.5 var(--mono); }
.layers { counter-reset: l; list-style: none; padding: 0; display: grid; gap: 0.85rem; }
.layers li { display: grid; grid-template-columns: 2.5rem minmax(0, 1fr); gap: 0 0.75rem; margin: 0; }
.layers li::before {
  counter-increment: l;
  content: counter(l);
  grid-row: span 2;
  font: 400 0.75rem/1 var(--mono);
  color: var(--accent);
  border: 1px solid #82e9ff66;
  border-radius: 999px;
  width: 1.8rem;
  height: 1.8rem;
  display: grid;
  place-items: center;
}
.layers span { color: var(--muted); }
kbd {
  font-size: 0.78rem;
  background: var(--key-bg);
  border: 1px solid var(--glass-line);
  border-bottom-width: 2px;
  border-radius: 6px;
  padding: 0.05rem 0.45rem;
  color: var(--fg);
}

/* ----- previous / next ----- */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 0.8rem; margin-top: 4rem; }
.pager a {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1rem 1.2rem;
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  background: #ffffff05;
  text-decoration: none;
  color: var(--fg);
  min-width: 0;
  transition: border-color 0.25s;
}
.pager a:hover { border-color: #a3b6ff55; }
.pager small { font: 400 0.68rem/1 var(--mono); text-transform: uppercase; letter-spacing: 0.12em; color: #a9abbb; }
.pager span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-weight: 500; }
.pager-next { grid-column: 2; text-align: right; }
.nav-prev, .nav-next {
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  font-size: 2.2rem;
  color: var(--muted);
  text-decoration: none;
  padding: 1.8rem 1.1rem;
  border-radius: var(--radius);
  display: none;
  transition: background 0.2s, color 0.2s;
}
.nav-prev:hover, .nav-next:hover { color: #fff; background: #ffffff08; }
.nav-prev { left: calc(var(--side-w) + 0.5rem); }
.nav-next { right: 0.5rem; }
.sidebar-hidden .nav-prev { left: 0.5rem; }
@media (min-width: 1240px) {
  .nav-prev, .nav-next { display: block; }
  .pager { display: none; }
}

@media (max-width: 900px) {
  .page { margin-left: 0; }
  .sidebar { transform: translateX(-100%); }
  .sidebar-open .sidebar { transform: none; box-shadow: 20px 0 60px -20px #000; background: #07080cf2; }
  .rows div { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 560px) {
  .book-title { position: static; transform: none; margin-left: 0.4rem; font-size: 0.95rem; }
  .book-title { gap: 0.45rem; }
  .book-title .sep, .book-title .dim:first-of-type { display: none; }
  .bar a.icon:not(.gh) { display: none; }
  .meta div { grid-template-columns: minmax(0, 1fr); }
}
@media (prefers-reduced-motion: reduce) {
  .sidebar, .page, .fold::before, summary::before { transition: none; }
}
@media print {
  .sidebar, .bar, .search, .pager, .nav-prev, .nav-next { display: none; }
  .page { margin: 0; }
  details > div { display: block; }
}