/* ============================================================
   Reader interface
   - Themes: light (default), dark
   - Layouts: single | double | scroll
============================================================ */

:root[data-theme="light"] {
  --r-bg: #f6f2ea;
  --r-bg-deep: #efe9dd;
  --r-ink: #1c1a16;
  --r-ink-soft: #2c2823;
  --r-muted: #6e665a;
  --r-muted-soft: #8a8275;
  --r-rule: #d9d2c2;
  --r-accent: #7a3f1f;
  --r-overlay: rgba(28, 26, 22, 0.45);
}

:root[data-theme="dark"] {
  --r-bg: #14110d;
  --r-bg-deep: #1c1813;
  --r-ink: #ece4d3;
  --r-ink-soft: #d8cfba;
  --r-muted: #8a8275;
  --r-muted-soft: #6e665a;
  --r-rule: #2e2820;
  --r-accent: #c98a5b;
  --r-overlay: rgba(0, 0, 0, 0.7);
}

/* ----- Body & shell ----- */

.reader-body {
  margin: 0;
  background: var(--r-bg);
  color: var(--r-ink);
  font-family: "Source Serif 4", ui-serif, Georgia, serif;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "kern", "liga", "onum";
  font-variation-settings: "opsz" 14;
  overflow: hidden;
  height: 100vh;
}

.reader {
  display: grid;
  grid-template-rows: auto 1fr auto;
  height: 100vh;
}

/* ----- Top bar ----- */

.reader__topbar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0.85rem 1.5rem;
  border-bottom: 1px solid var(--r-rule);
  background: var(--r-bg);
  z-index: 30;
}

.reader__topbar-left,
.reader__topbar-right {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.reader__topbar-right { justify-content: flex-end; }

.reader__topbar-center { text-align: center; min-width: 0; }
.reader__book-title {
  font-family: "Fraunces", ui-serif, serif;
  font-variation-settings: "opsz" 60, "wght" 500;
  font-size: 0.95rem;
  color: var(--r-ink);
  margin: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 36ch;
}
.reader__book-author {
  font-style: italic;
  font-size: 0.78rem;
  color: var(--r-muted);
  margin: 0.1rem 0 0;
}

.reader__icon-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: transparent;
  border: 0;
  color: var(--r-ink-soft);
  padding: 0.5rem 0.75rem;
  font: inherit;
  cursor: pointer;
  font-size: 0.78rem;
  text-transform: lowercase;
  font-variant-caps: all-small-caps;
  letter-spacing: 0.12em;
  transition: color 0.15s;
  text-decoration: none;
}
.reader__icon-btn:hover { color: var(--r-accent); }
.reader__icon-btn-label { display: inline-block; }

/* Buttons that should never show a label (universal-icon affordances). */
.reader__icon-btn--icon-only .reader__icon-btn-label { display: none; }

@media (max-width: 700px) {
  /* On phones, hide the centered title and the label of less-essential
     icon buttons (Contents has a recognizable hamburger icon). Layout,
     font-size, and theme buttons keep their labels because the label is
     the only thing that conveys the *current* state. */
  .reader__topbar-center { display: none; }
  .reader__icon-btn--mobile-icon-only .reader__icon-btn-label { display: none; }
  .reader__topbar { padding: 0.65rem 0.75rem; }
  .reader__icon-btn { padding: 0.5rem 0.5rem; gap: 0.3rem; font-size: 0.7rem; }
}

/* ----- TOC drawer ----- */

.reader__toc {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: min(420px, 88vw);
  background: var(--r-bg);
  border-right: 1px solid var(--r-rule);
  transform: translateX(-100%);
  transition: transform 0.3s ease;
  z-index: 50;
  overflow-y: auto;
}
.reader__toc[aria-hidden="false"] { transform: translateX(0); }

.reader__toc-inner { padding: 2.5rem 2rem 4rem; }

.reader__toc-eyebrow {
  font-variant-caps: all-small-caps;
  text-transform: lowercase;
  letter-spacing: 0.12em;
  color: var(--r-muted);
  font-size: 0.78rem;
  margin: 0 0 0.75rem;
}

.reader__toc-title {
  font-family: "Fraunces", ui-serif, serif;
  font-variation-settings: "opsz" 144, "wght" 400;
  font-size: 1.6rem;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--r-ink);
  margin: 0 0 0.5rem;
}
.reader__toc-author {
  font-style: italic;
  color: var(--r-muted);
  margin: 0 0 1.5rem;
  font-size: 0.95rem;
}
.reader__toc-rule {
  border: 0;
  border-top: 1px solid var(--r-rule);
  margin: 0 0 1.25rem;
}

.reader__toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.reader__toc-list .reader__toc-list {
  padding-left: 1.25rem;
  margin-top: 0.4rem;
  border-left: 1px solid var(--r-rule);
}
.reader__toc-item { margin: 0.4rem 0; }

.reader__toc-link {
  background: transparent;
  border: 0;
  color: var(--r-ink-soft);
  font: inherit;
  text-align: left;
  padding: 0.35rem 0;
  cursor: pointer;
  width: 100%;
  display: block;
  font-size: 0.95rem;
  line-height: 1.45;
  transition: color 0.15s;
  text-decoration: none;
}
.reader__toc-link:hover { color: var(--r-accent); }
.reader__toc-link.is-current { color: var(--r-accent); font-style: italic; }
.reader__toc-link--inert { color: var(--r-muted); cursor: default; }

.reader__toc-empty {
  color: var(--r-muted);
  font-style: italic;
  font-size: 0.9rem;
}

.reader__backdrop {
  position: fixed;
  inset: 0;
  background: var(--r-overlay);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
  z-index: 40;
}
.reader.is-toc-open .reader__backdrop {
  opacity: 1;
  pointer-events: auto;
}

/* ----- Main / content ----- */

.reader__main {
  position: relative;
  display: flex;
  align-items: stretch;
  overflow: hidden;
  background: var(--r-bg);
}

.reader__nav {
  background: transparent;
  border: 0;
  color: var(--r-muted-soft);
  cursor: pointer;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  transition: color 0.15s, background 0.15s;
}
.reader__nav:hover { color: var(--r-ink); background: var(--r-bg-deep); }
.reader__nav:disabled { color: transparent; cursor: default; pointer-events: none; }
@media (max-width: 700px) { .reader__nav { padding: 0 0.5rem; } }

.reader__viewport {
  flex: 1 1 auto;
  overflow: hidden;
  position: relative;
  display: flex;
  align-items: stretch;
  justify-content: center;
}

/* `.reader__page` is the clip window. Its width is the visible "spread"
   width; CSS columns inside `.reader__content` overflow past this wrapper
   horizontally and are clipped here. JS sets column-width to match the
   page wrapper exactly so columns line up to page boundaries. */
.reader__page {
  flex: 1 1 auto;
  height: 100%;
  margin: 0 clamp(1.5rem, 5vw, 5rem);
  overflow: hidden;
  position: relative;
}

.reader__content {
  font-family: "Source Serif 4", ui-serif, Georgia, serif;
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--r-ink);
  box-sizing: border-box;
  column-fill: auto;
  column-gap: 4rem;
  height: 100%;
  width: 100%;
  padding: 4rem 0;
  /* column-width set by JS in recomputePagination(). */
}

/* Font-size variants — applied via [data-font-size] on `.reader`. */
.reader[data-font-size="sm"] .reader__content { font-size: 0.95rem;  line-height: 1.65; }
.reader[data-font-size="md"] .reader__content { font-size: 1.125rem; line-height: 1.7;  }
.reader[data-font-size="lg"] .reader__content { font-size: 1.25rem;  line-height: 1.7;  }
.reader[data-font-size="xl"] .reader__content { font-size: 1.4rem;   line-height: 1.7;  }

@media (max-width: 700px) {
  .reader__content { column-gap: 2rem; padding: 2rem 0; }
  .reader__page    { margin: 0 1.25rem; }
}

/* ---- Single-page scroll mode ---- */
.reader[data-layout="scroll"] .reader__viewport {
  overflow-y: auto;
  scroll-behavior: smooth;
  align-items: flex-start;
}
.reader[data-layout="scroll"] .reader__page {
  overflow: visible;
  max-width: 38em;
  height: auto;
}
.reader[data-layout="scroll"] .reader__content {
  column-count: 1 !important;
  column-width: auto !important;
  height: auto;
  padding: 4rem 0 8rem;
  transform: none !important;
}
/* Side arrows stay visible in scroll mode so the reader can advance to the
   next/previous chapter at the chapter's bottom/top edge. They float over
   the content at low opacity so they don't compete with the prose. */
.reader[data-layout="scroll"] .reader__nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  height: auto;
  padding: 0.5rem 0.75rem;
  background: color-mix(in srgb, var(--r-bg) 80%, transparent);
  opacity: 0.4;
  transition: opacity 0.15s, color 0.15s;
}
.reader[data-layout="scroll"] .reader__nav:hover { opacity: 1; }
.reader[data-layout="scroll"] .reader__nav--prev { left: 0; }
.reader[data-layout="scroll"] .reader__nav--next { right: 0; }
@media (max-width: 700px) {
  .reader[data-layout="scroll"] .reader__nav { display: none; }
}

/* ---- Typography of chapter content ---- */
.reader__content h1,
.reader__content h2,
.reader__content h3,
.reader__content h4 {
  font-family: "Fraunces", ui-serif, serif;
  font-variation-settings: "opsz" 96, "wght" 500;
  letter-spacing: -0.01em;
  color: var(--r-ink);
  break-after: avoid;
  margin: 2.5em 0 1em;
  line-height: 1.2;
}
.reader__content h1 { font-size: 2rem; margin-top: 0; }
.reader__content h2 { font-size: 1.5rem; }
.reader__content h3 { font-size: 1.2rem; }

.reader__content p {
  margin: 0 0 1em;
  text-align: justify;
  hyphens: auto;
  -webkit-hyphens: auto;
}
.reader__content p + p { text-indent: 1.5em; margin-top: 0; }

.reader__content blockquote {
  border-left: 2px solid var(--r-rule);
  margin: 1.5em 0;
  padding: 0 0 0 1.25em;
  color: var(--r-ink-soft);
  font-style: italic;
}

.reader__content em, .reader__content i { font-style: italic; }
.reader__content strong, .reader__content b { font-weight: 600; }

.reader__content a {
  color: var(--r-accent);
  text-decoration: underline;
  text-decoration-color: var(--r-rule);
  text-underline-offset: 4px;
}

.reader__content img,
.reader__content image,
.reader__content svg {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 1.5em auto;
}

.reader__content hr {
  border: 0;
  text-align: center;
  margin: 2em 0;
  color: var(--r-muted);
}
.reader__content hr::after { content: "✦"; font-size: 1rem; }

.reader__loading {
  text-align: center;
  font-style: italic;
  color: var(--r-muted);
  padding: 4rem 0;
}

/* Inline chapter-boundary controls — appear at the start/end of every
   chapter so touch users (and anyone in scroll mode) can step between
   chapters without the TOC. */
.reader__chapter-endpoint {
  text-align: center;
  margin: 3rem 0 0;
  break-before: column;
}
.reader__chapter-endpoint--top {
  margin: 0 0 2.5rem;
  break-after: column;
}
.reader__chapter-endpoint button {
  background: transparent;
  border: 1px solid var(--r-rule);
  color: var(--r-ink);
  font: inherit;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  padding: 0.7rem 1.5rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.reader__chapter-endpoint button:hover {
  background: var(--r-ink);
  color: var(--r-bg);
  border-color: var(--r-ink);
}
.reader__chapter-endpoint-eyebrow {
  font-variant-caps: all-small-caps;
  text-transform: lowercase;
  letter-spacing: 0.12em;
  color: var(--r-muted);
  font-size: 0.78rem;
  margin: 0 0 1rem;
}

/* ----- Bottom bar ----- */

.reader__bottombar {
  padding: 0.75rem 1.5rem 1rem;
  border-top: 1px solid var(--r-rule);
  background: var(--r-bg);
  z-index: 20;
}

.reader__progress-meta {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-variant-caps: all-small-caps;
  text-transform: lowercase;
  letter-spacing: 0.12em;
  font-size: 0.7rem;
  color: var(--r-muted);
  margin-bottom: 0.5rem;
}
.reader__progress-pct { color: var(--r-ink-soft); }

.reader__progress-track {
  height: 2px;
  background: var(--r-rule);
  position: relative;
  overflow: hidden;
}
.reader__progress-fill {
  position: absolute;
  inset: 0 auto 0 0;
  width: 0%;
  background: var(--r-accent);
  transition: width 0.25s ease;
}