:root {
    --font-size: 21px; --line-height: 1.85; --content-width: 700px; --side-margin: 24px;
    --paragraph-spacing: 1.3em; --reader-font: Georgia, serif; --text-align: left; --focus-pos: 35%; --brightness: 1;
}
:root[data-reader-theme="paper"] { --bg: #f8f5ed; --surface: #fffcf4; --ink: #403e34; --muted: #777364; --line: #e4dfd0; --accent: #666f4c; --accent-hover: #48533a; --accent-soft: #eceedd; color-scheme: light; }
:root[data-reader-theme="light"] { --bg: #fff; --surface: #fff; --ink: #303438; --muted: #71767c; --line: #e6e9e9; --accent: #486458; --accent-soft: #eaf0ed; color-scheme: light; }
:root[data-reader-theme="sepia"] { --bg: #eee0c5; --surface: #f7eace; --ink: #594731; --muted: #7b694f; --line: #d6c4a3; --accent: #805c37; --accent-hover: #674727; --accent-soft: #e6d8b9; color-scheme: light; }
:root[data-reader-theme="dark"] { --bg: #242625; --surface: #303330; --ink: #d8ddd3; --muted: #a4ad9e; --line: #454b43; --accent: #b0be9c; --accent-hover: #c7d3b7; --accent-soft: #3b4534; color-scheme: dark; }
:root[data-reader-theme="oled"] { --bg: #000; --surface: #111; --ink: #d9d9d5; --muted: #969991; --line: #30312e; --accent: #b6c9a7; --accent-hover: #d2e1c6; --accent-soft: #20261c; color-scheme: dark; }
:root[data-reader-theme="midnight"] { --bg: #111c2d; --surface: #1b293e; --ink: #cfd9e9; --muted: #8fa3be; --line: #2b3d55; --accent: #a9c3e0; --accent-hover: #c3d8f0; --accent-soft: #293b52; color-scheme: dark; }
:root[data-reader-theme="forest"] { --bg: #182b25; --surface: #233b31; --ink: #d5e0c9; --muted: #9daf97; --line: #385246; --accent: #c3d7a8; --accent-hover: #dae8c7; --accent-soft: #344b36; color-scheme: dark; }
.reader-page { position: relative; display: flex; flex-direction: column; height: 100dvh; overflow: hidden; background: var(--bg); color: var(--ink); }
#reader-viewport { position: relative; flex: 1 1 auto; min-height: 0; overflow-y: auto; overflow-x: hidden; scrollbar-width: thin; scrollbar-color: var(--line) transparent; overflow-anchor: none; overscroll-behavior: contain; }
#reader-viewport::-webkit-scrollbar { width: 13px; height: 13px; }
#reader-viewport::-webkit-scrollbar-track { background: transparent; }
#reader-viewport::-webkit-scrollbar-thumb { background: var(--line); border-radius: 9px; border: 3px solid transparent; background-clip: padding-box; }
#reader-viewport::-webkit-scrollbar-thumb:hover { background: var(--accent); background-clip: padding-box; }
#reader-content { box-sizing: content-box; max-width: var(--content-width); padding: 48px var(--side-margin) 80vh; margin: auto; font: var(--font-size)/var(--line-height) var(--reader-font); text-align: var(--text-align); filter: brightness(var(--brightness)); }
.chapter-kicker { color: var(--muted); font: 10px/1.5 "Segoe UI", sans-serif; letter-spacing: .18em; margin-bottom: 22px; }
#chapter-title { font-family: var(--reader-font); font-size: 2.05em; line-height: 1.25; margin-bottom: 1.35em; letter-spacing: -.035em; }
.reader-block { margin: 0 0 var(--paragraph-spacing); overflow-wrap: break-word; }
.reader-block.type-heading { font: 1.4em/1.4 var(--reader-font); margin-block: 1.6em .8em; }
.reader-block.type-quote { border-left: 2px solid var(--line); padding-left: 1.1em; margin-left: 0; font-style: italic; }
.reader-block.type-list { padding-left: 1.15em; border-left: 2px solid var(--line); }
.reader-block.type-verse { white-space: pre-line; text-align: left; }
.reader-block.type-separator { height: 1px; border: 0; background: var(--line); margin-block: 2em; }
.chapter-end { text-align: center; padding: 50px 0 20px; font: 13px/1.8 "Segoe UI", sans-serif; color: var(--muted); }
.chapter-end > span { display: block; font-size: 24px; color: var(--warm); margin-bottom: 18px; }
.chapter-end .text-link { display: block; margin-top: 20px; }
.chapter-actions { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }
.reader-control { position: fixed; z-index: 10; background: color-mix(in srgb, var(--bg) 94%, transparent); backdrop-filter: blur(12px); transition: opacity .22s, transform .22s; }
.reader-top { position: relative; flex: 0 0 auto; display: flex; align-items: center; gap: 17px; padding: 13px 25px; border-bottom: 1px solid var(--line); overflow: hidden; max-height: 120px; transition: opacity .22s, max-height .24s ease, padding .24s ease, border-width .24s ease; }
.reader-title { display: flex; flex-direction: column; min-width: 0; gap: 2px; }
.reader-title strong { font-size: 12px; font-weight: 550; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.reader-title small { font-size: 10px; color: var(--muted); }
.reader-top nav { margin-left: auto; display: flex; gap: 4px; }
.reader-bottom { bottom: 18px; left: 50%; transform: translateX(-50%); border: 1px solid var(--line); border-radius: 14px; padding: 13px 22px 9px; width: 540px; max-width: calc(100% - 30px); box-shadow: 0 8px 45px #0000000a; }
.reading-status { display: flex; justify-content: space-between; gap: 12px; font-size: 10px; color: var(--muted); }
.playback-controls { display: flex; align-items: center; justify-content: center; gap: 7px; margin-top: 7px; }
.play-button { display: inline-flex; align-items: center; justify-content: center; width: 45px; height: 45px; border: 0; border-radius: 50%; background: var(--accent); color: var(--surface); margin-inline: 3px; }
.play-button[aria-pressed="true"] { box-shadow: 0 0 0 4px var(--accent-soft); }
.speed-display { background: none; border: 0; color: var(--ink); font-size: 12px; min-width: 68px; }
#elapsed-time { font-size: 10px; font-variant-numeric: tabular-nums; color: var(--muted); padding-inline: 10px; }
.reader-hint { text-align: center; color: var(--muted); font-size: 9px; margin: 5px 0 0; }
.controls-hidden .reader-control { opacity: 0; pointer-events: none; }
/* La barra superior va en el flujo flex: si al ocultarse colapsara su altura, el viewport
   crecería hacia arriba y todo el texto daría un salto. Se desvanece (opacity) manteniendo
   su altura, igual que en modo páginas, para que la lectura no se mueva. */
.controls-hidden .reader-bottom { transform: translate(-50%, 8px); }
.controls-hidden { cursor: none; }
.reader-panel { display: none; overflow-y: auto; position: fixed; width: 390px; max-width: calc(100vw - 20px); max-height: calc(100dvh - 96px); margin: 70px 18px auto auto; top: 0; right: 0; left: auto; bottom: auto; z-index: 60; border: 1px solid var(--line); border-radius: 13px; padding: 26px; background: var(--surface); color: var(--ink); box-shadow: 0 20px 80px #0002; font-size: 13px; }
.reader-panel.open { display: block; }
#chapters-panel.open { display: flex; flex-direction: column; overflow: hidden; }
.panel-backdrop { position: fixed; inset: 0; background: #0006; z-index: 55; display: none; }
.panel-backdrop.open { display: block; }
.panel-actions { margin-top: 14px; display: flex; justify-content: flex-end; }
.panel-heading { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 15px; }
.panel-heading h2 { font-size: 28px; margin: 0; }
.reader-panel > p { font-size: 12px; }
.reader-panel small { color: var(--muted); font-weight: 400; font-size: 10px; }
.reader-panel label { font-size: 11px; }
.reader-panel .form-grid { gap: 15px; }
.reader-panel input[type="range"] { width: 100%; accent-color: var(--accent); cursor: pointer; }
.reader-panel h3 { font-size: 15px; margin: 27px 0 17px; }
.reader-panel output { color: var(--muted); font-weight: 400; }
/* FASE 5 — ajustes: básico visible + avanzadas colapsadas. */
.reader-advanced { margin-top: 20px; border-top: 1px solid var(--line); }
.reader-advanced > summary { cursor: pointer; list-style: none; font-size: 11px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); padding: 14px 0; }
.reader-advanced > summary::-webkit-details-marker { display: none; }
.reader-advanced > summary::before { content: "+  "; color: var(--accent); }
.reader-advanced[open] > summary::before { content: "\2013  "; }
.reader-advanced[open] > summary { margin-bottom: 6px; }
#chapters-panel .panel-heading, #chapters-panel .panel-tabs { flex: 0 0 auto; }
#chapters-panel .panel-body { flex: 1 1 auto; min-height: 0; overflow-y: auto; margin: 0 -6px; padding: 2px 6px 0; }
.panel-tabs { display: flex; gap: 8px; margin-bottom: 15px; border-bottom: 1px solid var(--line); }
.panel-tabs button { border: 0; background: none; color: var(--muted); padding: 9px 6px; font-size: 12px; border-bottom: 2px solid transparent; margin-bottom: -1px; }
.panel-tabs button[aria-selected="true"] { color: var(--ink); border-bottom-color: var(--accent); }
.tab-count { color: var(--muted); font-size: 10px; }
#chapter-nav { display: flex; flex-direction: column; gap: 6px; }
#chapter-nav button, .saved-item { text-align: left; border: 1px solid var(--line); background: transparent; color: var(--ink); padding: 12px; border-radius: 6px; width: 100%; font-size: 12px; }
#chapter-nav button[aria-current="true"] { background: var(--accent-soft); border-color: var(--accent); }
.saved-item { margin-bottom: 8px; overflow-wrap: anywhere; }
#saved-items .muted { font-size: 12px; }
.saved-item small { display: block; margin-top: 5px; }
.saved-row { display: flex; gap: 6px; align-items: stretch; margin-bottom: 8px; }
.saved-row .saved-item { flex: 1 1 auto; margin-bottom: 0; }
.saved-delete { flex: 0 0 auto; border: 1px solid var(--line); background: transparent; color: var(--muted); border-radius: 6px; padding: 0 11px; font-size: 15px; line-height: 1; cursor: pointer; }
.saved-delete:hover { color: var(--warm); border-color: var(--warm); }
.reader-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.reader-stats > div { background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 16px; display: flex; flex-direction: column; }
.reader-stats span { font-size: 10px; color: var(--muted); min-height: 30px; }
.reader-stats strong { font: 26px/1.4 Georgia, serif; font-variant-numeric: tabular-nums; }
.reader-stats small { font-size: 10px; }
#focus-line { display: none; position: fixed; top: var(--focus-pos); left: 0; width: 100%; height: 3.3em; transform: translateY(-35%); border-block: 1px solid color-mix(in srgb, var(--accent) 20%, transparent); pointer-events: none; z-index: 2; }
.show-focus-line #focus-line { display: block; }
.focus-mode #reader-viewport { mask-image: linear-gradient(to bottom, #0005, #000a calc(var(--focus-pos) - 15%), #000 calc(var(--focus-pos) - 4%), #000 calc(var(--focus-pos) + 6%), #000a calc(var(--focus-pos) + 20%), #0005); }
.selection-toolbar { position: fixed; z-index: 25; left: 50%; bottom: 165px; transform: translateX(-50%); display: flex; gap: 5px; padding: 7px; background: var(--surface); border: 1px solid var(--line); border-radius: 8px; box-shadow: 0 8px 30px #0002; max-width: calc(100vw - 20px); flex-wrap: wrap; justify-content: center; }
.selection-toolbar button { border: 0; background: var(--accent-soft); color: var(--ink); font-size: 11px; padding: 10px; border-radius: 5px; }
.sync-prompt { position: fixed; z-index: 30; top: 90px; left: 50%; transform: translateX(-50%); width: 460px; max-width: calc(100vw - 30px); padding: 22px; background: var(--surface); border: 1px solid var(--line); border-radius: 9px; box-shadow: 0 15px 50px #0002; font-size: 13px; }
.reader-noscript { position: fixed; z-index: 40; bottom: 0; padding: 10px; background: var(--surface); font-size: 12px; }
.reader-page .toast { bottom: 180px; }
/* Riel de progreso del capítulo: fino, en el borde derecho bajo la cabecera, clicable/arrastrable.
   Sólo en modo Scroll (en Páginas ya hay indicador de página). No altera la posición canónica. */
.reader-rail { position: fixed; right: 15px; width: 4px; border-radius: 4px; background: color-mix(in srgb, var(--line) 55%, transparent); z-index: 9; cursor: pointer; touch-action: none; opacity: .55; transition: opacity .25s, width .18s, right .18s; }
.reader-rail:hover, .reader-rail.dragging { opacity: 1; width: 9px; right: 12px; }
.reader-rail .rail-fill { position: absolute; top: 0; left: 0; right: 0; height: 0; background: var(--accent); border-radius: 4px; }
.reader-rail .rail-bubble { position: absolute; right: 16px; transform: translateY(-50%); background: var(--surface); border: 1px solid var(--line); color: var(--ink); font: 10px/1.4 "Segoe UI", sans-serif; font-variant-numeric: tabular-nums; padding: 2px 7px; border-radius: 7px; white-space: nowrap; opacity: 0; transition: opacity .18s; pointer-events: none; }
.reader-rail:hover .rail-bubble, .reader-rail.dragging .rail-bubble { opacity: 1; }
.reader-mode-pages .reader-rail { display: none; }
.controls-hidden .reader-rail { opacity: 0; pointer-events: none; }

/* MODO PÁGINAS — una sola página a pantalla completa, paginada con columnas CSS.
   La página es una representación visual dinámica; la posición canónica sigue siendo
   block_id + character_offset (nunca un número de página). */
.reader-mode-pages #reader-viewport { overflow: hidden; touch-action: pan-y; }
.reader-mode-pages #reader-content {
    box-sizing: border-box; max-width: none; width: var(--page-w, 100%); margin: 0;
    height: var(--page-h, 100dvh);
    padding: calc(var(--page-top, 92px) + env(safe-area-inset-top)) 0 calc(var(--page-bottom, 130px) + env(safe-area-inset-bottom));
    column-width: var(--page-w, 100vw); column-gap: 0; column-fill: auto;
    transform: translateX(var(--page-shift, 0px)); will-change: transform;
}
.reader-mode-pages #reader-content.pager-anim { transition: transform .28s cubic-bezier(.22, .61, .36, 1); }
.reader-mode-pages .chapter-kicker, .reader-mode-pages #chapter-title, .reader-mode-pages .chapter-end,
.reader-mode-pages #blocks > * { padding-inline: var(--page-side, 24px); box-sizing: border-box; }
.reader-mode-pages #blocks { padding-inline: 0; }
.reader-mode-pages .chapter-kicker { padding-top: .6em; }
.reader-mode-pages.focus-mode #reader-viewport { mask-image: none; }
.reader-mode-pages .playback-controls, .reader-mode-pages .reader-hint, .reader-mode-pages #focus-line { display: none; }
.reader-mode-pages .reader-bottom { width: auto; left: 0; right: 0; transform: none; max-width: none; border-radius: 0; border-inline: 0; }
.reader-mode-pages.controls-hidden .reader-bottom { transform: translateY(8px); }
#page-shade { position: fixed; inset: 0; z-index: 8; pointer-events: none; opacity: 0; transition: opacity .18s; }
#page-shade.from-right { background: linear-gradient(to left, transparent 84%, rgba(0, 0, 0, .3)); }
#page-shade.from-left { background: linear-gradient(to right, transparent 84%, rgba(0, 0, 0, .3)); }
@media (prefers-reduced-motion: reduce) {
    .reader-mode-pages #reader-content.pager-anim { transition: none; }
    #page-shade { transition: none; }
}
@media (max-width: 600px) {
    .reader-top { padding: 10px 8px; gap: 5px; }
    .reader-title { flex: 1; }
    .reader-top nav { gap: 0; }
    .reader-top .icon-button { width: 35px; height: 40px; }
    #reader-content { padding-top: 32px; }
    #chapter-title { font-size: 1.65em; }
    .reader-panel { margin: auto; }
    .reader-bottom { bottom: max(10px, env(safe-area-inset-bottom)); padding: 12px 12px 8px; }
    .reading-status { font-size: 9px; }
    .playback-controls { gap: 2px; flex-wrap: wrap; }
    #elapsed-time { padding-inline: 6px; }
    .reader-hint { font-size: 8px; }
    .reader-title small { display: none; }
}
/* Notas de investigación (Fase H): marca sutil del fragmento + cita en el panel */
mark.reader-hl { background: color-mix(in srgb, var(--accent) 26%, transparent); color: inherit; border-radius: 3px; padding: 0 1px; box-decoration-break: clone; -webkit-box-decoration-break: clone; }
mark.reader-hl-yellow { background: rgba(240, 200, 90, .32); }
mark.reader-hl-green { background: rgba(110, 200, 140, .30); }
mark.reader-hl-blue { background: rgba(110, 170, 240, .30); }
mark.reader-hl-pink { background: rgba(240, 140, 190, .30); }
.research-quote { margin: 0 0 14px; padding: 10px 14px; border-left: 3px solid var(--accent); background: var(--accent-soft); color: var(--ink); font-style: italic; font-size: 13px; border-radius: 0 6px 6px 0; max-height: 160px; overflow: auto; }
#research-panel label, #recommend-panel label { display: flex; flex-direction: column; gap: 5px; margin-bottom: 12px; }
#research-panel label small, #recommend-panel label small { color: var(--muted); font-size: 11px; }

/* ── Audiolibro (Web Speech API): la voz narra y el texto avanza solo. ── */
/* Bloque en curso de narración: resaltado tenue que respeta el tema activo (--accent). */
.reader-block.voice-current { background: color-mix(in srgb, var(--accent) 14%, transparent); border-radius: 6px; box-shadow: 0 0 0 8px color-mix(in srgb, var(--accent) 14%, transparent); }
/* En Páginas el halo puede saltar de columna: basta con el fondo. */
body.reader-mode-pages .reader-block.voice-current { box-shadow: none; }
/* El botón de escuchar se ilumina mientras suena la narración. */
#toggle-listen.on { color: var(--accent); background: var(--accent-soft); }
#toggle-listen[disabled] { opacity: .4; cursor: not-allowed; }
/* Ajustes propios de la escucha, bajo los básicos. */
.reader-listen { margin-top: 18px; padding-top: 4px; border-top: 1px solid var(--line); }
.reader-listen label { display: flex; flex-direction: column; gap: 6px; margin-top: 12px; }