/* Notes reader: a fixed frame (contents on the left, page bar at the bottom); only the pages scroll */

.notes-body { --toc-w: 270px; }

.notes-toc {
  position: fixed;
  z-index: 4;
  top: 0;
  bottom: 0;
  left: 0;
  width: var(--toc-w);
  overflow-y: auto;
  padding: 22px 14px 28px 18px;
  border-right: 1px solid var(--rule);
  background: var(--bg);
  font-size: 0.8rem;
}
.notes-toc-title { margin: 0 0 10px 8px; color: var(--muted); font-size: 0.72rem; letter-spacing: 0.06em; text-transform: uppercase; }
.notes-toc a { display: block; padding: 3px 8px; border-radius: 4px; color: var(--text-2); line-height: 1.4; }
.notes-toc a:hover { background: var(--tag-bg); color: var(--accent); text-decoration: none; }
.notes-toc .toc-1 { margin-top: 8px; color: var(--text); font-weight: 700; }
.notes-toc .toc-1:first-child { margin-top: 0; }
.notes-toc .toc-2 { padding-left: 20px; }
.notes-toc .current { background: var(--tag-bg); color: var(--accent); }

/* the page area is its own scrolling viewport, so zoomed pages scroll sideways inside the frame */
.notes-pages {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: var(--toc-w);
  overflow: auto;
  overscroll-behavior: contain;
  padding: 24px 24px 84px;
  -webkit-user-select: none;
  user-select: none;
}
.notes-pages:focus { outline: none; }
.notes-sheet {
  display: grid;
  grid-template-columns: repeat(var(--cols, 1), var(--pw, 816px));
  gap: 18px;
  width: max-content;
  margin: 0 auto;
}
/* two-page view reads like a book: the first page sits alone on the right */
.notes-sheet.spread .sheet-page:first-child { grid-column: 2; }
.notes-sheet .sheet-page {
  position: relative;
  width: var(--pw, 816px);
  background: #fff;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.14);
}
.notes-sheet img {
  display: block;
  width: 100%;
  height: 100%;
  pointer-events: none;
  -webkit-user-drag: none;
  -webkit-touch-callout: none;
}
.notes-sheet .pl { position: absolute; border-radius: 2px; cursor: pointer; }
.notes-sheet .pl:hover { background: rgba(26, 95, 180, 0.12); box-shadow: inset 0 0 0 1px rgba(26, 95, 180, 0.35); }

.notes-bar {
  position: fixed;
  z-index: 5;
  left: calc(50% + var(--toc-w) / 2);
  bottom: 16px;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 10px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: var(--bg-elev);
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.12);
  color: var(--text-2);
  font-size: 0.8rem;
  white-space: nowrap;
}
.notes-bar button {
  height: 28px;
  min-width: 28px;
  padding: 0 8px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
  cursor: pointer;
}
.notes-bar button:hover { border-color: var(--muted); }
.nb-group { display: inline-flex; align-items: center; gap: 8px; }
.nb-view { padding-left: 10px; border-left: 1px solid var(--rule); }
.notes-zoom {
  height: 28px;
  padding: 0 6px;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
  cursor: pointer;
}
.notes-spread { display: inline-flex; align-items: center; justify-content: center; }
.nb-errata { padding-left: 10px; border-left: 1px solid var(--rule); }
.notes-errata {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 28px;
  padding: 0 10px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: var(--bg);
  color: var(--text);
  text-decoration: none;
}
.notes-errata:hover { border-color: var(--muted); color: var(--accent); text-decoration: none; }
.notes-errata svg { fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linejoin: round; }
.notes-spread svg { fill: none; stroke: currentColor; stroke-width: 1.4; }
.notes-spread[aria-pressed="true"] { border-color: var(--accent); background: var(--tag-bg); color: var(--accent); }
.notes-bar button:disabled { opacity: 0.35; cursor: default; }
.notes-prev, .notes-next, .notes-zoom-in, .notes-zoom-out { font-size: 1rem !important; line-height: 1; }
.notes-toc-btn { display: none; }
.notes-page {
  width: 3.4em;
  padding: 3px 4px;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
  text-align: center;
}

/* narrow screens: pages take the width, contents opens as a sheet from the bar */
@media (max-width: 1000px) {
  .notes-toc {
    top: auto;
    left: 12px;
    right: 12px;
    bottom: 64px;
    width: auto;
    max-height: 62vh;
    padding: 12px 8px;
    border: 1px solid var(--rule);
    border-radius: 10px;
    background: var(--bg-elev);
    box-shadow: 0 8px 28px rgba(0, 0, 0, 0.18);
    visibility: hidden;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.15s ease, transform 0.15s ease, visibility 0.15s;
  }
  .notes-toc.open { visibility: visible; opacity: 1; transform: none; }
  .notes-toc-btn { display: inline-block; }
  .notes-pages { left: 0; padding: 12px 10px 80px; }
  .notes-sheet { gap: 10px; }
  .nb-view { display: none; }
  .nb-errata { padding-left: 8px; }
  .notes-errata { padding: 0 7px; }
  .notes-errata span { display: none; }
  .notes-bar { left: 50%; }
}

/* printing (and print-to-PDF) shows a notice instead of the pages */
@media print {
  .notes-bar, .notes-toc, .notes-pages { display: none !important; }
  .notes-reader::after { content: "These notes can be read at alanknguyen.com and are not available for printing."; }
}