/* modemu2k doxygen theme
 * Overrides CSS custom properties defined in doxygen.css.
 * All foreground/background pairs meet WCAG AA (>= 4.5:1).
 *
 * Specificity note: stock doxygen.css sets nav/title vars at `html { }`
 * (light) and `html:not(.dark-mode) { }` inside a prefers-color-scheme
 * media block (specificity 0,1,1). A plain `:root` block (0,1,0) loses
 * to that in dark mode, leaving stock defaults in place. We pin the
 * overrides to `html, html:not(.dark-mode)` so the same selector wins
 * by cascade order in both light and dark, and we explicitly repeat
 * the most contrast-critical rules on `.sm-dox` to defend against
 * future stock CSS reshuffles.
 */

*, *::before, *::after { box-sizing: border-box; }

html,
html:not(.dark-mode) {
  /* Width cap for the centered content column. Used by #doc-content,
     #titlearea > table, and #main-nav .sm-dox so the title bar, top
     nav, and body content all share the same horizontal rhythm.
     Tweak in one place to change the layout. */
  --m2k-content-max-width: 1100px;

  /* Title bar: dark navy. #projectname/#projectbrief set explicitly below. */
  --title-background-color: #1a3a5c;
  --title-separator-color:  #2e86c1;

  /* Top nav bar and dropdown panels.
     --nav-menu-background-color drives both the bar and the dropdown body,
     so one dark value covers both. Foreground colors are tuned for #1a3a5c:
       #e8f2fb on #1a3a5c = 10.5:1 (AAA)
       #d0e8f8 on #1a3a5c = 7.1:1  (AAA)
       #a0c8e8 on #1a3a5c = 4.5:1  (AA)                                 */
  --nav-menu-background-color:  #1a3a5c;
  --nav-text-normal-color:      #e8f2fb;
  --nav-text-hover-color:       #ffffff;
  --nav-menu-foreground-color:  #d0e8f8;
  --nav-menu-button-color:      #e8f2fb;
  --nav-menu-active-bg:         #2e5f8a;
  --nav-menu-active-color:      #7ec8e3;
  --nav-arrow-color:            #a0c8e8;
  --nav-arrow-selected-color:   #c8e8ff;

  /* Links. #005ea6 on white = 5.9:1 (AA) */
  --page-link-color:         #005ea6;
  --page-visited-link-color: #005ea6;

  /* Member declaration table */
  --memdecl-background-color: #f0f4f8;
  --memdecl-border-color:     #b8d0e8;

  /* Member definition box */
  --memdef-title-background-color: #dce8f8;
  --memdef-proto-background-color: #eaf2fb;
  --memdef-border-color:           #a8c4e0;

  /* Section group headers. #003d80 on white = 10.4:1 (AAA) */
  --group-header-color:           #003d80;
  --group-header-separator-color: #2e86c1;
}

/* Defense-in-depth nav contrast: the CSS variables above are the primary
   mechanism, but stock doxygen themes have shipped with white-on-pale-blue
   .sm-dox bugs more than once. Pin the critical pair explicitly so contrast
   is guaranteed even if a future variable rename quietly breaks overrides. */
.sm-dox,
.sm-dox ul {
  background-color: #1a3a5c;
  background-image: none;
}
.sm-dox a,
.sm-dox a:focus,
.sm-dox a:active,
.sm-dox ul a,
.sm-dox ul a:focus,
.sm-dox ul a:active {
  color: #e8f2fb;
  text-shadow: none;
  background-image: none;
}
.sm-dox a:hover,
.sm-dox ul a:hover {
  color: #ffffff;
  background-color: #2e5f8a;
  background-image: none;
  text-shadow: none;
}

/* Title bar text (no CSS variable exposed for these).
   #ffffff on #1a3a5c = 11:1 (AAA); #c8e0f0 on #1a3a5c = 5.5:1 (AA) */
#projectname  { color: #ffffff; }
#projectbrief { color: #c8e0f0; }

/* Repo link in the title bar, right-aligned. Underlined so it reads as
   a link even when color alone fails (AA accessibility requirement). */
#m2k-repolink {
  text-align: right;
  white-space: nowrap;
  padding-right: 4px;
  vertical-align: middle;
}
#m2k-repolink a,
#m2k-repolink a:visited {
  color: #e8f2fb;
  text-decoration: underline;
  font-size: 14px;
}
#m2k-repolink a:hover,
#m2k-repolink a:focus {
  color: #ffffff;
}

/* Stronger top bar box-shadow for visual separation */
#top {
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}

/* Cap line length on wide desktops so prose stays readable, and add
   breathing room on the sides. The title bar and top nav keep their
   full-width navy backgrounds, but their *inner* content (title text,
   menu items) is centered to the same column as #doc-content (see
   --m2k-content-max-width above)
   so the whole page has one consistent left/right rhythm.

   Putting the background on #main-nav lets the .sm-dox ul shrink to
   the centered column without leaving the bar's edges unpainted. */
#doc-content {
  max-width: var(--m2k-content-max-width);
  margin: 0 auto;
  padding: 0 32px;
}
#titlearea > table {
  max-width: var(--m2k-content-max-width);
  width: 100%;
  margin: 0 auto;
  padding: 0 32px;
}
/* Make the name+brief cell consume slack so the repo-link cell parks
   against the right padding edge instead of hugging the brief text. */
#projectalign { width: 100%; }
#main-nav { background-color: #1a3a5c; }
#main-nav .sm-dox {
  max-width: var(--m2k-content-max-width);
  margin: 0 auto;
  padding-left: 32px;
  padding-right: 32px;
}
@media (max-width: 640px) {
  #doc-content,
  #titlearea > table,
  #main-nav .sm-dox { padding-left: 16px; padding-right: 16px; }
}

/* Typography. #111 on white = 19:1 (AAA) */
body, .contents, .textblock, td, th {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.65;
  color: #111111;
}

/* Code blocks. #111 on #f5f5f5 = 17:1 (AAA) */
div.fragment, pre.fragment {
  background: #f5f5f5;
  border: 1px solid #d0d0d0;
  border-left: 3px solid #2e86c1;
  border-radius: 0 3px 3px 0;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 13px;
  line-height: 1.5;
  color: #111111;
}

/* Footer. #555 on white = 7.4:1 (AA) */
address.footer, .footer { color: #555555; font-size: 13px; }

/* Hide the GitHub Actions CI badge inherited from README.md — it's
   redundant inside the docs site and clutters the main page intro. */
a[href*="/actions/workflows/"] { display: none; }

/* Main-page only: suppress the duplicate "modemu2k" headings.
   - .header carries the slim title bar showing the page name; useful
     on Files/ChangeLog/etc. where the page title differs from the
     project name, but redundant on the main page.
   - The README's `# modemu2k` H1 is the second copy of the project
     name; hide the first H1 in the textblock specifically.
   The .m2k-mainpage class is set by a script in header.html. */
html.m2k-mainpage .header { display: none; }
html.m2k-mainpage .textblock > h1.doxsection:first-of-type { display: none; }

/* Floating Table of Contents.
   Doxygen emits the [TOC] directive as <div class="contents"> wrapping
   a <div class="toc"> followed by the page body. We give the TOC its
   own grid column inside .contents and let it stick to the top of the
   viewport while scrolling. The body content narrows to make room
   rather than the TOC sitting on top of it.

   The breakpoint uses `em` so a user who zooms text up keeps the
   layout intact — pixel breakpoints break when the viewport shrinks
   below them at higher zoom levels. Below the breakpoint the TOC
   falls back to a normal block at the top of the page. */
@media (min-width: 60em) {
  div.contents {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 14em;
    column-gap: 1.5em;
  }
  /* Every direct child of .contents lands in the left column by default;
     only the TOC opts into the right column. */
  div.contents > * {
    grid-column: 1;
    min-width: 0;
  }
  div.contents > div.toc {
    grid-column: 2;
    grid-row: 1 / span 99;
    position: sticky;
    top: 1em;
    align-self: start;
    max-height: calc(100vh - 2em);
    overflow-y: auto;
    margin: 0;
    background: #f5f5f5;
    border: 1px solid #d0d0d0;
    border-radius: 3px;
    padding: 0.75em 1em;
    font-size: 13px;
    line-height: 1.5;
  }
  div.contents > div.toc h3 {
    margin-top: 0;
    margin-bottom: 0.5em;
    font-size: 14px;
  }
  div.contents > div.toc ul {
    padding-left: 1.2em;
    margin: 0.25em 0;
  }
}