/* Loaded with media="print" — every rule applies only during PDF render.
   Render the PDF at virtual 1080p so screen typography (rem, vh, vw) maps 1:1.
   The PDF reader scales the page to whatever physical size it needs at print time. */
@page {
  size: 1920px 1080px;
  margin: 0;
}

html, body {
  height: auto;
  margin: 0;
  overflow: visible;
  background: #fff;
}

/* The screen body footer (fixed page number + progress bar) shows ONE state.
   For per-page numbering in print we replace it with section::after + section background gradient below. */
body > footer { display: none; }

/* #deck no longer constrains to one viewport — sections stack across pages. */
#deck {
  height: auto;
  display: block;
}

/* Force every section to render at full page size, one per printed page. */
section {
  display: flex !important;
  page-break-after: always;
  break-after: page;
  page-break-inside: avoid;
  break-inside: avoid;
  /* Per-page progress bar: hairline rule at 5px above bottom, fill from left to --progress. */
  background-image:
    linear-gradient(var(--rule), var(--rule)),
    linear-gradient(
      to right,
      var(--ink) 0 var(--progress, 0%),
      transparent var(--progress, 0%) 100%
    );
  background-position: 0 calc(100% - 5px), 0 100%;
  background-size: 100% 1px, 100% 5px;
  background-repeat: no-repeat, no-repeat;
  -webkit-print-color-adjust: exact;
  print-color-adjust: exact;
}

section:last-child {
  page-break-after: auto;
  break-after: auto;
}

/* Per-page page number — uses the same coords as the screen #page-number so layout is 1:1. */
section::after {
  content: attr(data-num) " / " attr(data-total);
  position: absolute;
  right: 3vw;
  bottom: 3.5vh;
  font-size: 0.5rem;
  color: var(--muted);
  letter-spacing: 0.05em;
}

/* Menubar already position:fixed via the screen rule — fixed elements repeat on every printed page.
   Solid white background so it never visually merges into a slide with edge-to-edge content. */
#chapters {
  background: #fff;
}