/* =========================================================================
 * ON1 // docs — editorial newspaper reader
 * aesthetic: warm paper, ink, vermillion accents, generous typography
 * fonts: Familjen Grotesk (body, italic), Chakra Petch (mast),
 *        IBM Plex Mono (folios, code)
 * ========================================================================= */

:root {
  /* paper & ink */
  --ink:        #1d2025;   /* almost-black, warm */
  --ink-2:      #3a3a3a;
  --paper:      #f5f1e8;   /* aged off-white */
  --paper-2:    #ebe6d6;   /* darker stripe — code blocks, table stripes */
  --paper-3:    #e0dac7;
  --rule:       #d4cdb8;   /* dividers */
  --rule-soft:  #e4dfd0;
  --mute:       #6b6557;   /* sepia muted */
  --accent:     #b65d3a;   /* vermillion ink — current doc, accents, drop cap */
  --accent-2:   #456272;   /* faded blue — links (5.74:1 on paper, WCAG AA) */
  --warn:       #b54a3a;   /* errors */

  /* typography */
  --serif:   'Familjen Grotesk', Georgia, serif;     /* body */
  --display: 'Chakra Petch', 'IBM Plex Mono', monospace; /* masthead */
  --mono:    'IBM Plex Mono', 'JetBrains Mono', monospace;

  /* layout */
  --pad:       clamp(20px, 4vw, 64px);
  --pad-y:     clamp(18px, 2.5vw, 28px);
  --col-side:  240px;
  --col-toc:   200px;
  --col-text:  72ch;
  --hair:      1px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  /* faint paper texture: speckle via radial-gradients, plus a left thumb shadow */
  background-color: var(--paper);
  background-image:
    radial-gradient(1px 1px at 18% 22%, rgba(29, 32, 37, 0.025), transparent 50%),
    radial-gradient(1px 1px at 73% 64%, rgba(29, 32, 37, 0.025), transparent 50%),
    radial-gradient(1px 1px at 41% 81%, rgba(29, 32, 37, 0.018), transparent 50%),
    radial-gradient(1500px 700px at 50% -100px, rgba(182, 93, 58, 0.04), transparent 70%);
  background-attachment: fixed;
  min-height: 100vh;
}

a { color: var(--accent-2); text-decoration: none; }
a:hover { color: var(--accent); }

/* selection */
::selection { background: var(--accent); color: var(--paper); }

/* scrollbar — narrow, sepia */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--rule); border-radius: 0; }
::-webkit-scrollbar-thumb:hover { background: var(--mute); }

/* =========================================================================
 * masthead
 * ========================================================================= */

.mast {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: baseline;
  padding: 22px var(--pad) 16px;
  border-bottom: 3px double var(--ink);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--mute);
  text-transform: uppercase;
  letter-spacing: 0.16em;
}

.mast-l { display: flex; gap: 10px; align-items: baseline; }
.mast-c { display: flex; justify-content: center; }
.mast-r { display: flex; gap: 14px; justify-content: flex-end; align-items: baseline; }

.mast-brand {
  font-family: var(--display);
  font-size: 20px;
  letter-spacing: 0.04em;
  color: var(--ink);
}
.mast-pub {
  font-family: var(--display);
  font-size: 16px;
  letter-spacing: 0.18em;
  color: var(--accent);
}
.mast-em { color: var(--mute); }
.mast-tag {
  font-family: var(--serif);
  font-style: italic;
  font-size: 12px;
  text-transform: none;
  letter-spacing: 0;
  color: var(--mute);
}
.mast-sep { color: var(--rule); }
.mast-link {
  color: var(--mute);
  border-bottom: 1px dotted transparent;
  transition: 120ms ease;
}
.mast-link:hover { color: var(--accent); border-bottom-color: var(--accent); }

@media (max-width: 760px) {
  .mast { grid-template-columns: 1fr; gap: 8px; }
  .mast-c, .mast-r { justify-content: flex-start; }
}

/* =========================================================================
 * book layout — 3 columns on wide, stacked on narrow
 * ========================================================================= */

.book {
  display: grid;
  grid-template-columns: var(--col-side) minmax(0, 1fr) var(--col-toc);
  gap: clamp(28px, 4vw, 56px);
  padding: clamp(28px, 4vw, 56px) var(--pad) clamp(24px, 4vw, 56px);
  max-width: 1500px;
  margin: 0 auto;
  align-items: start;
}

@media (max-width: 1100px) {
  .book {
    grid-template-columns: var(--col-side) minmax(0, 1fr);
    gap: clamp(24px, 3vw, 40px);
  }
  .toc { display: none; }
}

@media (max-width: 760px) {
  .book {
    grid-template-columns: 1fr;
    padding: 24px var(--pad);
    gap: 28px;
  }
}

/* =========================================================================
 * left index
 * ========================================================================= */

.index {
  position: sticky;
  top: 24px;
  align-self: start;
  font-family: var(--mono);
  font-size: 12px;
  border-right: 1px solid var(--rule);
  padding-right: 18px;
  max-height: calc(100vh - 48px);
  display: flex; flex-direction: column;
  min-height: 0;
}

.index-head { margin-bottom: 14px; padding-bottom: 10px; border-bottom: 1px solid var(--rule); }
.index-eyebrow {
  display: block;
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--mute);
  text-transform: uppercase;
  margin-bottom: 4px;
}
.index-title {
  font-family: var(--display);
  font-weight: 400;
  font-size: 18px;
  letter-spacing: 0.04em;
  color: var(--ink);
  margin: 0;
  text-transform: lowercase;
}

.index-list {
  list-style: none;
  margin: 0;
  padding: 0 4px 0 0;
  flex: 1 1 auto;
  overflow-y: auto;
  scrollbar-gutter: stable;
}

.index-list li {
  margin: 0;
  border-bottom: 1px dashed var(--rule-soft);
}
.index-list li:last-child { border-bottom: none; }

.index-list .loading {
  padding: 8px 0;
  color: var(--mute);
  font-style: italic;
}

.index-list a.entry {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
  align-items: baseline;
  padding: 8px 6px 8px 14px;
  color: var(--ink-2);
  font-family: var(--serif);
  font-size: 14px;
  line-height: 1.35;
  position: relative;
  transition: 120ms ease;
  cursor: pointer;
}
.index-list a.entry:hover {
  color: var(--ink);
  background: var(--paper-2);
}
.index-list a.entry::before {
  content: "";
  position: absolute;
  left: 0; top: 50%;
  width: 5px; height: 5px;
  background: transparent;
  border: 1px solid var(--rule);
  transform: translateY(-50%);
  border-radius: 50%;
  transition: 120ms ease;
}
.index-list a.entry .entry-name {
  display: block;
  word-break: break-word;
}
.index-list a.entry .entry-meta {
  font-family: var(--mono);
  font-size: 9.5px;
  color: var(--mute);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.index-list a.entry.current {
  color: var(--ink);
  background: var(--paper-2);
}
.index-list a.entry.current::before {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--paper);
}
.index-list a.entry.current::after {
  content: "▶";
  position: absolute;
  right: 4px; top: 50%;
  transform: translateY(-50%);
  color: var(--accent);
  font-size: 9px;
}

.index-foot {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--mute);
  text-transform: uppercase;
  display: flex; flex-direction: column; gap: 6px;
}
.index-stat::before { content: "// "; color: var(--rule); }

.index-refresh {
  margin-top: 6px;
  background: transparent;
  border: 1px solid var(--rule);
  color: var(--mute);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  padding: 6px 10px;
  cursor: pointer;
  transition: 120ms ease;
  align-self: flex-start;
}
.index-refresh:hover {
  border-color: var(--accent);
  color: var(--accent);
}

@media (max-width: 760px) {
  .index { position: relative; max-height: none; border-right: none; padding-right: 0; padding-bottom: 24px; border-bottom: 1px solid var(--rule); }
}

/* =========================================================================
 * center page
 * ========================================================================= */

.page {
  min-width: 0;
  max-width: var(--col-text);
  margin: 0 auto;
  padding-bottom: 48px;
}

.page-folio {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-family: var(--mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--mute);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 28px;
}
.folio-c { letter-spacing: 0.24em; color: var(--accent); }

.article {
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
}

.article-loading {
  font-style: italic;
  color: var(--mute);
  font-size: 18px;
  text-align: center;
  padding: 80px 0;
}

/* article typography */
.article h1 {
  font-family: var(--display);
  font-weight: 400;
  font-size: clamp(32px, 5vw, 52px);
  letter-spacing: -0.01em;
  line-height: 1.1;
  margin: 0 0 8px;
  color: var(--ink);
}

/* a small kicker rule under the h1 */
.article h1 + p,
.article h1 + blockquote {
  margin-top: 24px;
}

.article h2 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 26px;
  line-height: 1.25;
  letter-spacing: -0.005em;
  margin: 56px 0 14px;
  padding-top: 18px;
  border-top: 1px solid var(--rule);
  color: var(--ink);
  scroll-margin-top: 24px;
}

.article h3 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 19px;
  margin: 36px 0 10px;
  color: var(--ink);
  scroll-margin-top: 24px;
}

.article h4, .article h5, .article h6 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 16px;
  margin: 24px 0 8px;
  color: var(--ink-2);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  scroll-margin-top: 24px;
}

.article p {
  margin: 0 0 18px;
  hyphens: auto;
  word-wrap: break-word;
  text-wrap: pretty;
}

/* drop cap on the very first paragraph after h1 */
.article > h1 + p::first-letter,
.article > h1 + blockquote + p::first-letter {
  font-family: var(--display);
  font-size: 4.6em;
  float: left;
  line-height: 0.85;
  margin: 0.06em 0.12em 0 -0.04em;
  color: var(--accent);
}

/* lists */
.article ul, .article ol {
  margin: 0 0 20px;
  padding-left: 1.4em;
}
.article li { margin: 4px 0; }
.article li::marker { color: var(--accent); }

/* inline code */
.article code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--paper-2);
  padding: 0.05em 0.4em;
  border: 1px solid var(--rule-soft);
  color: var(--ink);
  border-radius: 2px;
  word-break: break-word;
}

/* code blocks */
.article pre {
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.55;
  background: var(--paper-2);
  border-left: 3px solid var(--accent);
  padding: 16px 20px;
  margin: 22px 0;
  overflow-x: auto;
  color: var(--ink);
  white-space: pre;
  position: relative;
}
.article pre code {
  background: transparent;
  border: none;
  padding: 0;
  font-size: inherit;
  color: inherit;
  border-radius: 0;
}

/* tables */
.article table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  margin: 22px 0;
  font-variant-numeric: tabular-nums;
}
.article thead th {
  font-family: var(--serif);
  font-weight: 600;
  text-align: left;
  padding: 10px 14px;
  border-bottom: 2px solid var(--ink);
  color: var(--ink);
  text-transform: uppercase;
  font-size: 11px;
  letter-spacing: 0.1em;
}
.article tbody td {
  padding: 8px 14px;
  border-bottom: 1px solid var(--rule-soft);
  vertical-align: top;
}
.article tbody tr:nth-child(odd) td {
  background: rgba(212, 205, 184, 0.18);
}
.article tbody tr:last-child td { border-bottom: 1px solid var(--rule); }

/* block quotes — italic, vertical rule */
.article blockquote {
  margin: 22px 0;
  padding: 6px 0 6px 18px;
  border-left: 3px solid var(--accent-2);
  color: var(--ink-2);
  font-style: italic;
  font-size: 16.5px;
}
.article blockquote p:last-child { margin-bottom: 0; }

/* horizontal rule — three centered diamonds, like end-marks between sections */
.article hr {
  border: none;
  margin: 36px 0;
  text-align: center;
  height: 1em;
  position: relative;
}
.article hr::after {
  content: "❖  ❖  ❖";
  font-size: 13px;
  color: var(--rule);
  letter-spacing: 0.4em;
}

/* links inside the article */
.article a {
  color: var(--accent-2);
  border-bottom: 1px solid currentColor;
  transition: 120ms ease;
}
.article a:hover {
  color: var(--accent);
  background: rgba(182, 93, 58, 0.08);
}
.article a[target="_blank"]::after {
  content: "↗";
  font-size: 0.78em;
  margin-left: 2px;
  color: var(--mute);
}

/* images */
.article img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 18px 0;
  border: 1px solid var(--rule);
}

/* strong & em */
.article strong { font-weight: 600; color: var(--ink); }
.article em { font-style: italic; }

/* heading anchors invisible by default */
.article h1 a, .article h2 a, .article h3 a {
  border: none;
  color: inherit;
}

/* end-of-article ornaments */
.article-foot {
  margin: 56px 0 12px;
  text-align: center;
}
.end-mark {
  font-family: var(--mono);
  color: var(--rule);
  letter-spacing: 0.6em;
  font-size: 10px;
}

/* error / not-found state */
.article .alert {
  border: 1px solid var(--warn);
  border-left-width: 4px;
  padding: 14px 18px;
  background: rgba(181, 74, 58, 0.05);
  margin: 24px 0;
  font-size: 14.5px;
}
.article .alert h3 {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  margin: 0 0 8px;
  color: var(--warn);
  border: none;
  padding: 0;
}
.article .alert button {
  margin-top: 10px;
  background: transparent;
  border: 1px solid var(--warn);
  color: var(--warn);
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  padding: 6px 12px;
  cursor: pointer;
}
.article .alert button:hover {
  background: var(--warn);
  color: var(--paper);
}

/* =========================================================================
 * right TOC
 * ========================================================================= */

.toc {
  position: sticky;
  top: 24px;
  align-self: start;
  font-family: var(--mono);
  font-size: 11.5px;
  border-left: 1px solid var(--rule);
  padding-left: 18px;
  max-height: calc(100vh - 48px);
  overflow-y: auto;
}
.toc-head { margin-bottom: 12px; }
.toc-eyebrow {
  display: block;
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--mute);
  text-transform: uppercase;
}

.toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.toc-list li { margin: 0; }

.toc-list a {
  display: block;
  padding: 5px 6px 5px 12px;
  color: var(--mute);
  border-left: 1px solid transparent;
  line-height: 1.4;
  transition: 120ms ease;
  font-family: var(--serif);
  font-size: 12.5px;
  word-break: break-word;
}
.toc-list a:hover { color: var(--ink); border-left-color: var(--rule); }
.toc-list a.active {
  color: var(--accent);
  border-left-color: var(--accent);
  background: rgba(182, 93, 58, 0.05);
}

/* indent by heading level */
.toc-list li[data-level="1"] > a { font-weight: 600; color: var(--ink); padding-left: 8px; }
.toc-list li[data-level="2"] > a { padding-left: 14px; }
.toc-list li[data-level="3"] > a { padding-left: 22px; font-size: 11.5px; }
.toc-list li[data-level="4"] > a { padding-left: 30px; font-size: 11px; color: var(--mute); }
.toc-list li[data-level="5"] > a,
.toc-list li[data-level="6"] > a { padding-left: 38px; font-size: 11px; color: var(--mute); }

.toc-list a code {
  font-family: var(--mono);
  font-size: 0.92em;
  background: var(--paper-2);
  padding: 0 3px;
  border-radius: 2px;
}

/* =========================================================================
 * colophon
 * ========================================================================= */

.colophon {
  margin: 36px 0 0;
  padding: 18px var(--pad) 24px;
  border-top: 1px solid var(--ink);
  border-top-style: double;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--mute);
  letter-spacing: 0.16em;
  text-transform: uppercase;
}
.colophon a { color: var(--mute); }
.colophon a:hover { color: var(--accent); }
.colo-mark { color: var(--ink); font-family: var(--display); letter-spacing: 0.05em; }
.colo-sep { color: var(--rule); }
.colo-stamp::before { content: "● "; color: var(--accent); }

/* =========================================================================
 * tiny progressive-reveal animation
 * ========================================================================= */

@keyframes settle {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: none; }
}
.article > * {
  animation: settle 240ms cubic-bezier(0.2, 0, 0, 1) both;
}

/* respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  .article > * { animation: none; }
}