/* paperforge "paper look": research-article styling over the PreTeXt modern
   theme. Goals: LaTeX-familiar fonts, black-and-white, a wide single column,
   and quiet knowl/detail boundaries (light background, no heavy chrome). */

/* -- 6. LaTeX-like prose fonts. Math is already Modern via MathJax.  Prefer
      a locally installed Latin Modern face, with a stable serif fallback. -- */

:root:not(.dark-mode) {
  /* -- 5. black and white: the theme derives nearly everything from these -- */
  --primary-color: #111111;
  --secondary-color: #222222;
  --doc-title-color: #111111;
  --byline-color: #333333;
  --banner-background: #ffffff;
  --navbar-background: #f6f6f6;
  --toc-border-color: #dddddd;
  --tocitem-highlight-background: #e8e8e8;
  --tocitem-highlight-text-color: #111111;
  --activated-content-bg: #ececec;
  /* paper-look palette (dark counterparts below) */
  --paper-ink: #111111;
  --paper-underline: #bbbbbb;
  --paper-field: #f5f5f5;      /* born-hidden knowl field */
  --paper-field-xref: #f7f7f7; /* injected xref knowl field */
  --paper-layer: #ffffff;      /* nested knowl layer */
  --paper-hairline: #dddddd;
  --paper-toc-bg: #fafafa;
  --paper-toc-ink: #222222;
  --paper-toc-active-bg: #e8e8e8;
  --paper-toc-active-ink: #111111;
}
/* dark mode keys on the theme's .dark-mode class on :root
   (readability-options.js sets it from the system preference and the user
   toggle; theme.css has no media queries, so neither may we). The palette
   sits a step off the theme's dark body (#23241f). */
:root.dark-mode {
  --activated-content-bg: rgba(255, 255, 255, 0.08);
  --paper-ink: #f2f2f2;
  --paper-underline: #66665f;
  --paper-field: #2c2d27;
  --paper-field-xref: #2a2b25;
  --paper-layer: #1d1e19;
  --paper-hairline: #4a4b44;
  --paper-toc-bg: #202119;
  --paper-toc-ink: #cfd0ca;
  --paper-toc-active-bg: #33342c;
  --paper-toc-active-ink: #f2f2f2;
}

/* the theme flashes the :target element for orientation after a fragment
   jump; its 10s salmon fade reads as an error on a B/W page — keep the
   affordance, neutral and brief */
:target { animation-duration: 1.5s; }

/* light TOC sidebar: a paper's margin, not a book's chrome (the dark
   counterpart values live on the variables above) */
.ptx-sidebar .ptx-toc, .ptx-toc {
  background: var(--paper-toc-bg);
}
.ptx-toc .toc-item, .ptx-toc .toc-title-box a, .ptx-toc a {
  background: transparent;
  color: var(--paper-toc-ink);
}
.ptx-toc .toc-item.active, .ptx-toc .toc-current a {
  background: var(--paper-toc-active-bg);
  color: var(--paper-toc-active-ink);
}

/* one-page build: prev/up/next render as permanently-disabled placeholders
   (navbar and content footer) — hide them; a chunked build re-enables them
   automatically since only .disabled is hidden */
.ptx-navbar .treebuttons .button.disabled,
.ptx-content-footer .button.disabled { display: none; }

/* -- 2. wider content column: the theme hardcodes 696px on .ptx-content -- */
.ptx-main > .ptx-content { max-width: 58rem; }
.ptx-content-footer { max-width: 58rem; }

/* PreTeXt's default Runestone footer slot is replaced in custom-html.xsl by
   a text credit for the tool actually used to build this paper. */
.ptx-page-footer > .paperforge-link {
  display: flex;
  align-items: center;
  min-height: 3em;
  font-family: "Computer Modern Serif", "Latin Modern Roman", Georgia, serif;
  font-size: 0.95rem;
  text-decoration: none;
}
.ptx-page-footer > .paperforge-link:hover,
.ptx-page-footer > .paperforge-link:focus-visible {
  text-decoration: underline;
  text-underline-offset: 2px;
}


/* -- 6 cont.: prose in Computer Modern -- */
.ptx-content, .ptx-content .para, .ptx-page, .ptx-masthead .title-container {
  font-family: "Computer Modern Serif", "Latin Modern Roman", Georgia, serif;
}
.ptx-content .frontmatter .author-status-note {
  margin-top: 0.2rem;
  font-size: 0.92em;
}
.ptx-content .heading, .ptx-content h1, .ptx-content h2, .ptx-content h3,
.ptx-content h4, .ptx-content h5 {
  font-family: "Computer Modern Serif", "Latin Modern Roman", Georgia, serif;
}
/* division-heading ladder: the theme's subsection/subsubsection sizes
   (1.15em) fall below theorem-like headings (1.25em); keep every division
   heading at least lemma-sized, ordered by depth under section (1.3em) */
.ptx-content section.subsection > .heading { font-size: 1.275em; }
.ptx-content section.subsubsection > .heading { font-size: 1.25em; }

/* -- 5 cont.: links quiet (papers are ink); keep affordance on hover -- */
.ptx-content a.internal, .ptx-content .xref {
  color: var(--paper-ink);
  text-decoration: underline;
  text-decoration-color: var(--paper-underline);
  text-underline-offset: 2px;
}
.ptx-content a.internal:hover, .ptx-content .xref:hover {
  text-decoration-color: var(--paper-ink);
}
/* knowl links already carry the theme's state-aware dotted border (hidden
   on :hover/:focus/[open]) — adding our underline gave them a double line
   that flickered with focus. One affordance only. */
.ptx-content a.xref[data-knowl], .ptx-content a.xref[data-knowl]:hover {
  text-decoration: none;
}

/* -- 3. quiet knowls: light gray field instead of borders/boxes -- */
.ptx-content details.born-hidden-knowl {
  border: none;
  background: var(--paper-field);
  border-radius: 4px;
  padding: 0.35rem 0.7rem;
  margin: 0.6rem 0;
}
.ptx-content details.born-hidden-knowl > summary.knowl__link {
  color: var(--paper-ink);
  font-style: italic;
  text-decoration: none;
  list-style-position: outside;
}
.ptx-content details.born-hidden-knowl > summary.knowl__link .heading {
  color: var(--paper-ink);
}
.ptx-content details.born-hidden-knowl .knowl__content {
  border: none;
  background: transparent;
  box-shadow: none;
  padding: 0.2rem 0 0.1rem;
}
/* nested knowls: a knowl surface opened inside another knowl surface is
   grey-on-grey without a boundary. Step the inner one to white with a
   hairline so it reads as a layer. Injected xref knowls are the
   div.knowl__content[id^=knowl-uid-] elements (knowl.js); born-hidden
   details and .lean-knowl doc panels are the other two surfaces. */
.ptx-content details.born-hidden-knowl div.knowl__content[id^="knowl-uid-"],
.ptx-content details.born-hidden-knowl details.born-hidden-knowl,
.ptx-content details.born-hidden-knowl .lean-knowl,
.ptx-content details.born-hidden-knowl .section-knowl,
.ptx-content div.knowl__content[id^="knowl-uid-"] div.knowl__content[id^="knowl-uid-"],
.ptx-content div.knowl__content[id^="knowl-uid-"] details.born-hidden-knowl,
.ptx-content div.knowl__content[id^="knowl-uid-"] .lean-knowl,
.ptx-content div.knowl__content[id^="knowl-uid-"] .section-knowl {
  background: var(--paper-layer);
  border: 1px solid var(--paper-hairline);
  border-radius: 4px;
  padding: 0.35rem 0.7rem;
}

/* theorem-like blocks: no colored bars or boxes — amsart is flat -- */
.ptx-content article.theorem-like,
.ptx-content article.definition-like,
.ptx-content article.remark-like {
  border: none;
  background: transparent;
  box-shadow: none;
  padding-left: 0;
}

/* Bibliography keys are longer than the modern theme's default 7% label
   column, and unbroken commit hashes or URLs can otherwise run into the
   entry text. Give the keys enough room and allow link/code text to wrap. */
.ptx-content .references .bib {
  display: grid;
  grid-template-columns: 10rem minmax(0, 1fr);
  column-gap: 0.75rem;
  align-items: start;
}
.ptx-content .references .bib .bibitem,
.ptx-content .references .bib .bibitem + .bibentry {
  display: block;
  width: auto;
  min-width: 0;
  margin: 0;
}
.ptx-content .references .bibitem,
.ptx-content .references .bibentry,
.ptx-content .references .bibentry a,
.ptx-content .references .bibentry code {
  overflow-wrap: anywhere;
  word-break: break-word;
}
@media screen and (max-width: 640px) {
  .ptx-content .references .bib {
    grid-template-columns: minmax(0, 1fr);
    row-gap: 0.1rem;
    margin-top: 0.7rem;
  }
  .ptx-content .references .bibitem {
    font-size: 0.9em;
  }
}

/* xref preview knowls (click-to-open cross references) — same quiet field */
.ptx-content .knowl__content {
  background: var(--paper-field-xref);
  border: none;
  box-shadow: none;
  border-radius: 4px;
}

/* ToC visible by default on wide screens (owner request 2026-07-27). The
   theme's toggle still works: closing adds .hidden, which wins here. */
@media screen and (min-width: 1000px) {
  .ptx-sidebar:not(.hidden) { display: block; }
}