/*
  Reader surface: the paper page, typography for prose and Markdown blocks,
  page-mode viewport, scroll-mode column, and the quiet reader controls.
  Typography values come from CSS custom properties set by the settings module.
*/

.reader {
  position: relative;
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  min-height: 0;
  background: var(--paper-bg);
}

/* Top bar: title + minimal controls. Stays quiet. */
.reader__bar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 16px;
  border-bottom: 1px solid var(--line-soft);
  background: color-mix(in srgb, var(--paper-bg) 92%, var(--paper-surface) 8%);
  flex: 0 0 auto;
}

.reader__title {
  flex: 1 1 auto;
  font-family: var(--ui-font);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink-soft);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.reader__bar-actions {
  display: flex;
  gap: 6px;
  flex: 0 0 auto;
}

/* Close-document control sits on the left, before the title. Quiet but clearly
   a discoverable action (subtle border), never an unlabeled icon. */
.reader__close {
  flex: 0 0 auto;
  border-color: var(--line-soft);
}
.reader__close:hover {
  background: color-mix(in srgb, var(--paper-bg) 88%, var(--ink) 12%);
  border-color: var(--line-strong);
}

.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: var(--control-size);
  min-height: var(--control-size);
  padding: 6px 10px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  color: var(--ink-soft);
  font-family: var(--ui-font);
  font-size: 0.9rem;
  font-weight: 600;
  transition: background-color 160ms ease, border-color 160ms ease;
}

.icon-button:hover {
  background: color-mix(in srgb, var(--paper-bg) 88%, var(--ink) 12%);
  border-color: var(--line-soft);
}

/* Disabled controls (e.g. Prev/Next at the first/last page) read as inactive
   instead of looking clickable. */
.icon-button:disabled,
.icon-button[disabled] {
  opacity: 0.38;
  cursor: default;
}
.icon-button:disabled:hover,
.icon-button[disabled]:hover {
  background: transparent;
  border-color: transparent;
}

/* Stage holds the paper surface centered on desktop. */
.reader__stage {
  position: relative;
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  justify-content: center;
  align-items: stretch;
  overflow: hidden;
}

/* Paper surface with subtle texture and grain. */
.paper {
  position: relative;
  width: 100%;
  background: var(--paper-surface);
}

.paper::after {
  /* Subtle paper grain overlay. Opacity scales with texture-strength pref. */
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: url("../assets/textures/paper-noise.svg");
  background-size: 180px 180px;
  opacity: calc(0.22 * var(--texture-strength));
  mix-blend-mode: multiply;
  z-index: 1;
}

html[data-theme="dark"] .paper::after {
  mix-blend-mode: screen;
}

/* Content column: the typographic measure lives here. */
.content {
  position: relative;
  z-index: 2;
  max-width: var(--reader-measure);
  margin: 0 auto;
  font-family: var(--reader-font);
  font-size: var(--reader-font-size);
  line-height: var(--reader-line-height);
  color: var(--ink);
  text-align: var(--reader-align);
  hyphens: auto;
}

/* ---------- Prose + Markdown element styling ---------- */

.content p {
  margin: 0 0 var(--reader-para-spacing);
}

.content h1,
.content h2,
.content h3,
.content h4 {
  font-family: var(--reader-font);
  font-weight: 700;
  line-height: 1.25;
  color: var(--ink);
  margin: 1.4em 0 0.5em;
  text-align: left;
}

.content h1 { font-size: 1.6em; }
.content h2 { font-size: 1.35em; }
.content h3 { font-size: 1.15em; }
.content h4 { font-size: 1.02em; }
.content > :first-child { margin-top: 0; }

.content strong { font-weight: 700; }
.content em { font-style: italic; }

.content blockquote {
  margin: var(--reader-para-spacing) 0;
  padding: 0.1em 0 0.1em 1em;
  border-left: 2px solid var(--line-strong);
  color: var(--ink-soft);
  font-style: italic;
}

.content ul,
.content ol {
  margin: 0 0 var(--reader-para-spacing);
  padding-left: 1.4em;
}

.content li {
  margin: 0.2em 0;
}

.content li > ul,
.content li > ol {
  margin: 0.2em 0;
}

.content hr {
  border: none;
  border-top: 1px solid var(--line-strong);
  margin: 1.8em auto;
  width: 40%;
}

.content a {
  color: var(--ink-soft);
  text-decoration: underline;
  text-decoration-color: var(--accent-underline);
  text-underline-offset: 2px;
}

.content a:hover {
  text-decoration-color: var(--ink);
}

/* Inline code: distinct but not loud. */
.content code {
  font-family: var(--mono-font);
  font-size: 0.9em;
  background: var(--code-bg);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

/* Fenced code blocks: legible, contained, never break the page width. */
.content pre {
  margin: var(--reader-para-spacing) 0;
  padding: 0.9em 1em;
  background: var(--code-bg);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.content pre code {
  display: block;
  background: none;
  padding: 0;
  font-size: 0.82em;
  line-height: 1.5;
  white-space: pre;
  color: var(--ink-soft);
}

/* Line-numbered fenced code: fixed gutter + horizontally scrollable code.
   The gutter shares the code font-size and line-height so number N aligns with
   source line N. The gutter is never selectable, so copying code stays clean. */
.content pre.has-line-numbers {
  display: flex;
  gap: 0.8em;
  overflow-x: visible;
}
.content pre.has-line-numbers .code-gutter {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  text-align: right;
  user-select: none;
  -webkit-user-select: none;
  padding-right: 0.7em;
  border-right: 1px solid var(--line-soft);
  color: var(--ink-muted);
  font-family: var(--mono-font);
  font-size: 0.82em;
  line-height: 1.5;
  font-variant-numeric: tabular-nums;
}
.content pre.has-line-numbers .code-line-number {
  display: block;
}
.content pre.has-line-numbers code {
  flex: 1 1 auto;
  min-width: 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* Tables render readably and stay inside the column. */
.content table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--reader-para-spacing) 0;
  font-size: 0.92em;
}
.content th,
.content td {
  border: 1px solid var(--line-soft);
  padding: 0.4em 0.6em;
  text-align: left;
}
.content th {
  font-weight: 700;
  background: var(--code-bg);
}

/* Image placeholder — remote images are never fetched. */
.md-image-placeholder {
  display: inline-block;
  padding: 0.2em 0.6em;
  margin: 0.2em 0;
  border: 1px dashed var(--line-strong);
  border-radius: 4px;
  color: var(--ink-muted);
  font-family: var(--ui-font);
  font-size: 0.82em;
  font-style: normal;
}

/* Escaped raw HTML shown as literal source text. */
.md-raw-html {
  font-family: var(--mono-font);
  font-size: 0.85em;
  color: var(--ink-muted);
}

/* Two mount points inside .paper — one per reading mode. */
#reader-scroll,
#page-viewport {
  display: none;
}

/* ---------- Scroll mode ---------- */

.reader[data-mode="scroll"] .reader__stage {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.reader[data-mode="scroll"] .paper {
  min-height: 100%;
}

.reader[data-mode="scroll"] #reader-scroll {
  display: block;
}

.reader[data-mode="scroll"] .content {
  padding: 48px 28px 96px;
}

/* ---------- Page mode ---------- */

.reader[data-mode="paged"] .reader__stage {
  overflow: hidden;
}

/* Touch behavior: in page mode, allow native vertical pan and pinch-zoom while
   leaving horizontal movement for the swipe controller to recognize a page
   turn. In scroll mode, vertical panning stays native. Code blocks keep both
   axes so a horizontal drag scrolls the code, not the page. */
.reader[data-mode="paged"] .reader__stage,
.reader[data-mode="paged"] .page-viewport,
.reader[data-mode="scroll"] .reader__stage,
.reader[data-mode="scroll"] #reader-scroll {
  touch-action: pan-y pinch-zoom;
}

.reader pre,
.reader code,
.reader .code-block {
  touch-action: pan-x pan-y;
}

.reader[data-mode="paged"] .paper {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.reader[data-mode="paged"] #page-viewport {
  display: block;
}

/* The pane clips overflow; the content is offset by the paginator. */
.page-viewport {
  position: relative;
  flex: 1 1 auto;
  overflow: hidden;
  padding: 40px 28px 8px;
}

.reader[data-mode="paged"] .content {
  height: 100%;
}

/* Column-based pagination: text flows into stacked columns, and we shift
   horizontally to reveal the current page. */
.reader[data-mode="paged"] .content--paged {
  column-fill: auto;
  height: 100%;
}

/* ---------- Reader footer: navigation + progress ---------- */

.reader__footer {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 16px;
  border-top: 1px solid var(--line-soft);
  flex: 0 0 auto;
  font-family: var(--ui-font);
}

.reader__progress {
  flex: 1 1 auto;
  text-align: center;
  font-size: 0.82rem;
  color: var(--ink-muted);
  letter-spacing: 0.02em;
}

.reader[data-mode="scroll"] .page-nav {
  display: none;
}

/* Edge tap/click zones for page turns (page mode only). */
.page-zone {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 22%;
  z-index: 3;
  background: transparent;
  border: none;
  cursor: pointer;
}
.page-zone--prev { left: 0; }
.page-zone--next { right: 0; }
.reader[data-mode="scroll"] .page-zone { display: none; }

/* Progress hidden when the preference is off. */
.reader[data-progress="off"] .reader__progress {
  visibility: hidden;
}