:root {
  color-scheme: light;
  --reader-bg: #f1eee7;
  --reader-surface: #ffffff;
  --reader-surface-soft: #f7f5f0;
  --reader-ink: #18302d;
  --reader-muted: #657672;
  --reader-line: #d9dfdc;
  --reader-line-strong: #b8c4c0;
  --reader-primary: #1a8e78;
  --reader-primary-dark: #126858;
  --reader-primary-soft: #e5f5f1;
  --reader-danger: #b42343;
  --reader-focus: #b42343;
  --reader-board-light: #eee4d1;
  --reader-board-dark: #2f9e8e;
  --reader-coord-inline: 16px;
  --reader-coord-rank-gap: 4px;
  --reader-coord-block: 20px;
  --reader-shadow: 0 8px 30px rgba(24, 48, 45, 0.12);
  --reader-header-height: 68px;
  --reader-footer-height: 34px;
  --reader-tab-height: 0px;
  --reader-split: 55%;
  --reader-radius: 12px;
  font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html,
body {
  min-width: 320px;
  min-height: 100%;
  margin: 0;
}

body {
  overflow: hidden;
  color: var(--reader-ink);
  background: var(--reader-bg);
  font-family: inherit;
}

button,
input,
select,
textarea {
  color: inherit;
  font: inherit;
}

button,
summary,
input[type="checkbox"] {
  cursor: pointer;
}

button:disabled,
input:disabled,
textarea:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

[hidden] {
  display: none !important;
}

:focus-visible {
  outline: 3px solid rgba(180, 35, 67, 0.38);
  outline-offset: 2px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 8px;
  left: 8px;
  padding: 10px 14px;
  border-radius: 8px;
  color: #fff;
  background: var(--reader-primary-dark);
  transform: translateY(-150%);
}

.skip-link:focus {
  transform: translateY(0);
}

.reader-app {
  display: grid;
  grid-template-rows: var(--reader-header-height) var(--reader-tab-height) minmax(0, 1fr) var(--reader-footer-height);
  width: 100vw;
  height: 100dvh;
}

.app-header {
  z-index: 10;
  grid-row: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 8px clamp(14px, 2vw, 28px);
  color: #fff;
  background: #173f3a;
  box-shadow: 0 2px 12px rgba(11, 30, 27, 0.2);
}

.brand {
  display: inline-flex;
  align-items: center;
  min-width: 0;
  gap: 11px;
  color: inherit;
  text-decoration: none;
}

.brand__logo {
  display: block;
  width: 48px;
  height: 48px;
  flex: 0 0 48px;
  object-fit: contain;
}

.brand__copy {
  display: grid;
  min-width: 0;
  line-height: 1.2;
}

.brand__copy strong {
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  letter-spacing: -0.01em;
}

.brand__copy span {
  margin-top: 2px;
  color: #b8d4ce;
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.header-status {
  display: flex;
  align-items: center;
  gap: 10px;
}

.save-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 36px;
  padding: 7px 11px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  color: #dcece8;
  background: rgba(255, 255, 255, 0.08);
  font-size: 0.76rem;
  font-weight: 600;
}

.save-status i {
  color: #67d8b9;
}

.mobile-panel-tabs {
  display: none;
  grid-row: 2;
}

.study-workspace {
  grid-row: 3;
  display: grid;
  grid-template-columns: minmax(0, var(--reader-split)) 12px minmax(0, 1fr);
  min-height: 0;
  padding: 10px;
}

.study-panel {
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr) auto;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  border: 1px solid var(--reader-line);
  border-radius: var(--reader-radius);
  background: var(--reader-surface);
  box-shadow: var(--reader-shadow);
}

.pdf-panel {
  grid-column: 1;
}

.chess-panel {
  grid-column: 3;
  container: chess-panel / inline-size;
}

.panel-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 65px;
  padding: 10px 14px 9px 17px;
  border-bottom: 1px solid var(--reader-line);
  background: var(--reader-surface);
}

.panel-title-group {
  min-width: 0;
}

.panel-kicker {
  display: block;
  margin-bottom: 3px;
  color: var(--reader-primary-dark);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.panel-title-group h1,
.panel-title-group h2 {
  margin: 0;
  overflow: hidden;
  color: var(--reader-ink);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.25;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.panel-heading-actions,
.toolbar-group,
.comment-actions,
.dialog-actions,
.dialog-actions > div {
  display: flex;
  align-items: center;
  gap: 6px;
}

.panel-heading-actions {
  flex: 0 0 auto;
}

.panel-toolbar {
  display: flex;
  align-items: center;
  gap: 6px;
  min-height: 50px;
  padding: 5px 8px;
  overflow-x: auto;
  border-bottom: 1px solid var(--reader-line);
  background: var(--reader-surface-soft);
  scrollbar-width: thin;
}

.toolbar-separator {
  width: 1px;
  height: 26px;
  flex: 0 0 1px;
  margin: 0 2px;
  background: var(--reader-line-strong);
}

.toolbar-spacer {
  flex: 1 0 8px;
}

.compact-menu,
.mobile-study-tray,
.study-sheet-heading,
.study-sheet-backdrop {
  display: none;
}

.compact-menu {
  position: relative;
  flex: 0 0 auto;
}

.compact-menu > summary {
  display: inline-flex;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 0 10px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-size: 0.76rem;
  font-weight: 700;
  list-style: none;
}

.compact-menu > summary::-webkit-details-marker {
  display: none;
}

.compact-menu[open] > summary {
  color: var(--reader-primary-dark);
  border-color: var(--reader-line);
  background: var(--reader-surface);
}

.compact-menu:not([open]) .compact-menu__surface {
  display: none;
}

.compact-menu__surface {
  position: fixed;
  z-index: 90;
  right: max(8px, var(--reader-safe-right, env(safe-area-inset-right)));
  display: grid;
  width: min(286px, calc(100vw - 16px - var(--reader-safe-left, env(safe-area-inset-left)) - var(--reader-safe-right, env(safe-area-inset-right))));
  max-height: min(72dvh, 520px);
  gap: 3px;
  padding: 8px;
  overflow: auto;
  border: 1px solid var(--reader-line-strong);
  border-radius: 11px;
  background: var(--reader-surface);
  box-shadow: 0 18px 46px rgba(24, 48, 45, 0.24);
}

.compact-menu__surface .text-button {
  width: 100%;
  min-height: 44px;
  justify-content: flex-start;
}

.compact-menu__search {
  min-width: 0;
  min-height: 44px;
}

.icon-button,
.text-button,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  transition: color 150ms ease, background-color 150ms ease, border-color 150ms ease, box-shadow 150ms ease;
}

.icon-button {
  width: 40px;
  min-width: 40px;
  padding: 0;
  color: var(--reader-ink);
  background: transparent;
  font-size: 0.98rem;
}

.icon-button:hover,
.text-button:hover {
  border-color: var(--reader-line);
  background: var(--reader-surface);
}

.app-header .icon-button {
  color: #fff;
}

.app-header .icon-button:hover {
  border-color: rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.1);
}

.text-button {
  gap: 7px;
  min-width: max-content;
  padding: 0 10px;
  color: var(--reader-ink);
  background: transparent;
  font-size: 0.78rem;
}

.text-button--danger {
  color: var(--reader-danger);
}

.button {
  gap: 8px;
  min-height: 44px;
  padding: 0 16px;
  font-size: 0.84rem;
}

.button--compact {
  min-height: 38px;
  padding: 0 11px;
  font-size: 0.78rem;
}

.button--primary {
  color: #fff;
  border-color: #177b69;
  background: #177b69;
  box-shadow: 0 2px 6px rgba(26, 142, 120, 0.18);
}

.button--primary:hover {
  border-color: var(--reader-primary-dark);
  background: var(--reader-primary-dark);
}

.button--danger {
  color: #fff;
  border-color: var(--reader-danger);
  background: var(--reader-danger);
  box-shadow: 0 2px 6px rgba(180, 35, 67, 0.2);
}

.button--danger:hover {
  border-color: #8f1832;
  background: #8f1832;
}

.button--secondary {
  color: var(--reader-primary-dark);
  border-color: #9bc6bc;
  background: var(--reader-primary-soft);
}

.button--secondary:hover {
  border-color: var(--reader-primary);
  background: #d6eee8;
}

.button--ghost {
  color: var(--reader-danger);
  border-color: #e8b7c2;
  background: var(--reader-surface);
}

.page-control {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  color: var(--reader-muted);
  font-size: 0.73rem;
  white-space: nowrap;
}

.page-control input {
  width: 48px;
  height: 34px;
  padding: 4px;
  border: 1px solid var(--reader-line-strong);
  border-radius: 6px;
  background: var(--reader-surface);
  text-align: center;
  -moz-appearance: textfield;
}

.page-control input::-webkit-inner-spin-button,
.page-control input::-webkit-outer-spin-button {
  margin: 0;
  -webkit-appearance: none;
}

.zoom-label {
  min-width: 45px;
  color: var(--reader-muted);
  font-size: 0.72rem;
  font-weight: 600;
  text-align: center;
}

.pdf-search {
  display: flex;
  align-items: center;
  gap: 5px;
  min-width: 170px;
}

.search-field {
  display: flex;
  align-items: center;
  min-width: 150px;
  gap: 7px;
  padding: 0 9px;
  border: 1px solid var(--reader-line-strong);
  border-radius: 8px;
  background: var(--reader-surface);
}

.search-field i {
  color: var(--reader-muted);
  font-size: 0.78rem;
}

.search-field input {
  width: 100%;
  min-width: 80px;
  height: 34px;
  padding: 0;
  border: 0;
  outline: 0;
  background: transparent;
  font-size: 0.74rem;
}

.search-results {
  position: absolute;
  z-index: 8;
  top: 10px;
  right: 10px;
  width: min(430px, calc(100% - 20px));
  padding: 7px;
  border: 1px solid var(--reader-line-strong);
  border-radius: 9px;
  color: var(--reader-muted);
  background: var(--reader-surface);
  box-shadow: 0 12px 30px rgba(24, 48, 45, 0.18);
  font-size: 0.68rem;
}

.pdf-reader-body {
  position: relative;
  display: flex;
  min-width: 0;
  min-height: 0;
  background: #d7dcda;
}

/* Primer uso: el estado vacío conserva un solo llamado a abrir el PDF. */
.pdf-panel:has(#pdf-document-view[data-pdf-state="empty"]) .pdf-toolbar,
.pdf-panel:has(#pdf-document-view[data-pdf-state="empty"]) .panel-heading-actions {
  display: none;
}

.atril-onboarding-hint {
  display: none;
}

@media (max-width: 640px), (max-height: 600px) and (pointer: coarse) {
  .reader-app[data-mobile-layout="combined"] .atril-onboarding-hint:not([hidden]) {
    position: absolute;
    z-index: 18;
    right: auto;
    bottom: 8px;
    left: 8px;
    display: flex;
    width: calc(100vw - 16px - var(--reader-safe-left, env(safe-area-inset-left)) - var(--reader-safe-right, env(safe-area-inset-right)));
    max-width: 520px;
    min-width: 0;
    align-items: center;
    gap: 10px;
    padding: 9px 10px;
    border: 1px solid #9bc7bd;
    border-radius: 11px;
    color: var(--reader-ink);
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 8px 24px rgba(24, 48, 45, 0.18);
  }

  .atril-onboarding-hint p {
    min-width: 0;
    margin: 0;
    flex: 1 1 auto;
    font-size: 0.68rem;
    line-height: 1.4;
  }

  .atril-onboarding-hint .button {
    min-height: 44px;
    flex: 0 0 auto;
    padding-inline: 11px;
  }
}

@media (max-height: 600px) and (pointer: coarse) and (orientation: landscape) {
  .reader-app[data-mobile-layout="combined"] .atril-onboarding-hint:not([hidden]) {
    top: 8px;
    right: auto;
    bottom: auto;
    left: 8px;
    width: min(280px, calc(100% - 16px));
  }
}

.pdf-thumbnails {
  width: 138px;
  flex: 0 0 138px;
  overflow: auto;
  border-right: 1px solid #aeb8b4;
  background: #edf0ef;
}

.pdf-stage {
  position: relative;
  flex: 1 1 auto;
  min-width: 0;
  min-height: 0;
  overflow: auto;
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
}

@media (any-pointer: coarse) {
  /* La pinza pertenece al visor PDF; evita que Chrome/Safari escalen el tablero. */
  .pdf-stage {
    touch-action: pan-x pan-y;
  }

  .pdf-stage.is-pinching {
    overscroll-behavior: none;
  }

  .pdf-stage.is-pinching .pdf-pages {
    -webkit-user-select: none;
    user-select: none;
  }
}

.empty-state {
  display: grid;
  place-items: center;
  align-content: center;
  min-height: 100%;
  padding: 32px 20px;
  color: var(--reader-ink);
  text-align: center;
}

.empty-state__icon {
  display: grid;
  width: 74px;
  height: 74px;
  place-items: center;
  margin-bottom: 14px;
  border: 1px solid #e0aebe;
  border-radius: 18px;
  color: var(--reader-danger);
  background: #fff5f7;
  font-size: 2rem;
}

.empty-state h2 {
  margin: 0;
  font-size: clamp(1.1rem, 2vw, 1.35rem);
}

.empty-state > p {
  max-width: 540px;
  margin: 8px auto 18px;
  color: var(--reader-muted);
  font-size: 0.82rem;
  line-height: 1.55;
}

.pdf-drop-zone {
  display: grid;
  width: min(100%, 430px);
  place-items: center;
  gap: 7px;
  padding: clamp(20px, 4vh, 36px) 20px;
  border: 2px dashed #82afa5;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.8);
}

.pdf-drop-zone.is-dragover {
  border-color: var(--reader-primary-dark);
  background: var(--reader-primary-soft);
}

.pdf-drop-zone > i {
  margin-bottom: 3px;
  color: var(--reader-primary);
  font-size: 1.55rem;
}

.pdf-drop-zone strong {
  font-size: 0.94rem;
}

.pdf-drop-zone span {
  margin-bottom: 6px;
  color: var(--reader-muted);
  font-size: 0.75rem;
}

.empty-state .empty-state__hint {
  margin-bottom: 0;
  font-size: 0.68rem;
}

.pdf-pages {
  width: 100%;
  min-height: 100%;
  padding: 18px;
}

.panel-status,
.panel-footnote {
  display: flex;
  align-items: center;
  min-height: 30px;
  margin: 0;
  padding: 5px 12px;
  overflow: hidden;
  border-top: 1px solid var(--reader-line);
  color: var(--reader-muted);
  background: var(--reader-surface-soft);
  font-size: 0.67rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.panel-footnote {
  gap: 7px;
}

.workspace-divider {
  display: grid;
  grid-column: 2;
  place-items: center;
  min-width: 12px;
  min-height: 12px;
  touch-action: none;
  cursor: col-resize;
}

.workspace-divider__handle {
  display: grid;
  width: 7px;
  height: 52px;
  place-items: center;
  border: 1px solid var(--reader-line-strong);
  border-radius: 6px;
  color: var(--reader-muted);
  background: var(--reader-surface);
  font-size: 0.62rem;
  box-shadow: 0 2px 7px rgba(24, 48, 45, 0.12);
}

.workspace-divider:hover .workspace-divider__handle,
.workspace-divider:focus-visible .workspace-divider__handle,
body.is-resizing .workspace-divider__handle {
  color: #fff;
  border-color: var(--reader-primary);
  background: var(--reader-primary);
}

body.is-resizing,
body.is-resizing * {
  cursor: col-resize !important;
  user-select: none !important;
}

.chess-workspace {
  min-width: 0;
  min-height: 0;
  padding: clamp(8px, 1.4vw, 14px);
  overflow: auto;
  overscroll-behavior: contain;
  background: #ebe8e0;
}

.board-column {
  width: min(100%, 680px);
  margin: 0 auto;
}

.board-shell {
  padding: 7px;
  border: 1px solid #bbc6c2;
  border-radius: 10px;
  background: var(--reader-surface);
  box-shadow: 0 4px 16px rgba(24, 48, 45, 0.1);
}

.player-label {
  min-height: 24px;
  padding: 3px 4px;
  color: var(--reader-muted);
  font-size: 0.68rem;
  font-weight: 600;
}

.player-label--top {
  text-align: right;
}

.chess-board {
  position: relative;
  width: 100%;
  aspect-ratio: 1;
  overflow: visible;
  border-radius: 5px;
  background: var(--reader-board-light);
}

/* El marco reserva espacio fuera del cuadrado, igual que tablero/tablero.html. */
.board-coordinate-frame {
  width: 100%;
  padding: 0 0 var(--reader-coord-block) var(--reader-coord-inline);
}

.board-coordinate-frame > .chess-board,
.board-coordinate-frame > .position-editor-board {
  width: 100%;
}

/* El gesto dentro de cada tablero pertenece a SilicioBoard; el PDF conserva su scroll nativo. */
.chess-board,
.chess-board *,
#position-editor-board,
#position-editor-board * {
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
  touch-action: none;
}

.chess-board .silicio-board-native,
.position-editor-board .silicio-board-native {
  position: relative;
  width: 100%;
  height: 100%;
}

.chess-board coords,
.position-editor-board coords {
  position: absolute;
  z-index: 10;
  color: var(--reader-muted);
  font-family: "Inter", system-ui, sans-serif;
  font-size: 11px;
  font-weight: 600;
  line-height: 1;
  opacity: 1;
  pointer-events: none;
  text-shadow: none;
}

.chess-board coords.files,
.position-editor-board coords.files {
  right: 0;
  bottom: calc(-1 * var(--reader-coord-block));
  left: 0;
  display: flex;
  width: 100%;
  height: 16px;
  align-items: center;
  transform: none;
}

.chess-board coords.ranks,
.position-editor-board coords.ranks {
  top: 0;
  bottom: 0;
  left: calc(-1 * var(--reader-coord-inline));
  display: flex;
  width: 16px;
  height: 100%;
  align-items: center;
  transform: none;
}

/* El tablero nativo acerca los ranks 1 px al borde; este canal da aire sin reducir el tablero. */
.chess-board.silicio-board-native coords.ranks.left,
.position-editor-board.silicio-board-native coords.ranks.left {
  left: calc(-1 * var(--reader-coord-inline));
  width: var(--reader-coord-inline);
  padding-right: var(--reader-coord-rank-gap);
  align-items: flex-end;
}

.chess-board coords coord,
.position-editor-board coords coord {
  position: static;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  transform: none;
}

.chess-board.silicio-board-native coords.ranks coord,
.position-editor-board.silicio-board-native coords.ranks coord {
  transform: none;
}

.chess-board silicio-board-surface,
.position-editor-board silicio-board-surface,
.workbench-board silicio-board-surface {
  background-color: var(--reader-board-light) !important;
  background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 8 8"><g id="a"><g id="b"><g id="c"><g id="d"><rect width="1" height="1" id="e" fill="%23EEE4D1"/><use x="1" y="1" href="%23e"/><rect y="1" width="1" height="1" id="f" fill="%232F9E8E"/><use x="1" y="-1" href="%23f"/></g><use x="2" href="%23d"/></g><use x="4" href="%23c"/></g><use y="2" href="%23b"/></g><use y="4" href="%23a"/></svg>') !important;
  background-position: center !important;
  background-repeat: no-repeat !important;
  background-size: 100% 100% !important;
}

.chess-board piece.white.king,
.position-editor-board piece.white.king,
.workbench-board piece.white.king {
  background-image: url("../../tablero/piezassilicio/wK.svg") !important;
}

.chess-board piece.white.queen,
.position-editor-board piece.white.queen,
.workbench-board piece.white.queen {
  background-image: url("../../tablero/piezassilicio/wQ.svg") !important;
}

.chess-board piece.white.rook,
.position-editor-board piece.white.rook,
.workbench-board piece.white.rook {
  background-image: url("../../tablero/piezassilicio/wR.svg") !important;
}

.chess-board piece.white.bishop,
.position-editor-board piece.white.bishop,
.workbench-board piece.white.bishop {
  background-image: url("../../tablero/piezassilicio/wB.svg") !important;
}

.chess-board piece.white.knight,
.position-editor-board piece.white.knight,
.workbench-board piece.white.knight {
  background-image: url("../../tablero/piezassilicio/wN.svg") !important;
}

.chess-board piece.white.pawn,
.position-editor-board piece.white.pawn,
.workbench-board piece.white.pawn {
  background-image: url("../../tablero/piezassilicio/wP.svg") !important;
}

.chess-board piece.black.king,
.position-editor-board piece.black.king,
.workbench-board piece.black.king {
  background-image: url("../../tablero/piezassilicio/bK.svg") !important;
}

.chess-board piece.black.queen,
.position-editor-board piece.black.queen,
.workbench-board piece.black.queen {
  background-image: url("../../tablero/piezassilicio/bQ.svg") !important;
}

.chess-board piece.black.rook,
.position-editor-board piece.black.rook,
.workbench-board piece.black.rook {
  background-image: url("../../tablero/piezassilicio/bR.svg") !important;
}

.chess-board piece.black.bishop,
.position-editor-board piece.black.bishop,
.workbench-board piece.black.bishop {
  background-image: url("../../tablero/piezassilicio/bB.svg") !important;
}

.chess-board piece.black.knight,
.position-editor-board piece.black.knight,
.workbench-board piece.black.knight {
  background-image: url("../../tablero/piezassilicio/bN.svg") !important;
}

.chess-board piece.black.pawn,
.position-editor-board piece.black.pawn,
.workbench-board piece.black.pawn {
  background-image: url("../../tablero/piezassilicio/bP.svg") !important;
}

.chess-board piece,
.position-editor-board piece {
  background-position: center !important;
  background-repeat: no-repeat !important;
  background-size: cover !important;
}

.board-loading {
  display: grid;
  height: 100%;
  place-items: center;
  align-content: center;
  gap: 8px;
  color: var(--reader-primary-dark);
  font-size: 0.78rem;
  font-weight: 600;
}

.board-loading img {
  width: clamp(54px, 12vw, 76px);
  height: auto;
}

.board-status {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 32px;
  color: var(--reader-muted);
  font-size: 0.72rem;
  font-weight: 600;
}

.turn-indicator {
  width: 11px;
  height: 11px;
  border: 1px solid #5e6c69;
  border-radius: 50%;
  background: var(--reader-surface);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.15);
}

.study-notes {
  display: grid;
  grid-template-rows: minmax(170px, 1fr) auto;
  min-width: 0;
  min-height: 300px;
  gap: 10px;
  margin-top: 10px;
}

.moves-card,
.comment-card {
  display: grid;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  border: 1px solid var(--reader-line);
  border-radius: 9px;
  background: var(--reader-surface);
}

.moves-card {
  grid-template-rows: auto auto minmax(0, 1fr);
}

.comment-card {
  grid-template-rows: auto auto auto;
  padding-bottom: 8px;
}

.card-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-height: 39px;
  padding: 8px 10px;
  border-bottom: 1px solid var(--reader-line);
}

.card-heading h3,
.card-heading label {
  margin: 0;
  font-size: 0.78rem;
  font-weight: 700;
}

.variation-hint,
#selected-move-label {
  overflow: hidden;
  color: var(--reader-muted);
  font-size: 0.62rem;
  text-align: right;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.moves-list {
  min-height: 150px;
  padding: 10px;
  overflow: auto;
  color: var(--reader-ink);
  font-size: 0.8rem;
  line-height: 1.7;
  scrollbar-gutter: stable;
}

.moves-empty {
  display: flex;
  min-height: 100%;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: var(--reader-muted);
  text-align: center;
}

.study-move {
  display: inline-flex;
  align-items: baseline;
  gap: 3px;
  margin: 1px 4px 1px 0;
}

.study-move__number {
  color: var(--reader-muted);
  font-size: 0.7rem;
  font-weight: 600;
}

.study-move__button {
  min-height: 28px;
  padding: 3px 6px;
  border: 1px solid transparent;
  border-radius: 5px;
  color: var(--reader-ink);
  background: transparent;
  font-weight: 600;
}

.study-move__button:hover {
  border-color: var(--reader-line);
  background: var(--reader-surface-soft);
}

.study-move__button.is-current {
  color: #fff;
  border-color: var(--reader-primary-dark);
  background: var(--reader-primary-dark);
}

.study-move__comment {
  color: #596a66;
  font-size: 0.72rem;
  font-style: italic;
}

.study-variation {
  display: inline;
  margin: 0 4px;
  padding: 2px 4px;
  border-radius: 5px;
  color: #48605a;
  background: var(--reader-primary-soft);
  font-size: 0.74rem;
}

.variation-context {
  border-bottom: 1px solid var(--reader-line);
  background: linear-gradient(135deg, var(--reader-primary-soft), #fff 72%);
}

.variation-context[hidden],
.variation-context__menu[hidden] {
  display: none;
}

.variation-context__summary {
  display: flex;
  min-height: 44px;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 5px 8px 5px 10px;
}

.variation-context__selection {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: 7px;
  color: var(--reader-muted);
  font-size: 0.66rem;
}

.variation-context__selection > span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.variation-context__selection strong {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  color: var(--reader-primary-dark);
  font-size: 0.78rem;
}

.variation-context__trigger,
.variation-context__menu button {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  gap: 7px;
  border: 1px solid var(--reader-line);
  border-radius: 8px;
  color: var(--reader-primary-dark);
  background: var(--reader-surface);
  font: inherit;
  font-size: 0.7rem;
  font-weight: 700;
}

.variation-context__trigger {
  flex: 0 0 auto;
  min-height: 44px;
  padding: 5px 9px;
}

.variation-context__trigger[aria-expanded="true"],
.variation-context__trigger:hover,
.variation-context__menu button:hover {
  border-color: var(--reader-primary);
  background: var(--reader-primary-soft);
}

.variation-context__menu {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 6px;
  padding: 0 8px 8px;
}

.variation-context__menu button {
  width: 100%;
  min-height: 44px;
  padding: 6px 9px;
}

.variation-context__menu .variation-context__delete {
  color: var(--reader-danger);
}

.variation-context__menu .variation-context__delete:hover {
  border-color: #da8da0;
  background: #fff4f6;
}

.comment-card textarea,
.position-editor-options textarea {
  width: calc(100% - 20px);
  margin: 9px 10px 6px;
  resize: vertical;
  border: 1px solid var(--reader-line-strong);
  border-radius: 7px;
  padding: 9px;
  background: var(--reader-surface);
  font-size: 0.75rem;
  line-height: 1.45;
}

.comment-actions {
  justify-content: space-between;
  padding: 0 10px;
}

#comment-character-count {
  color: var(--reader-muted);
  font-size: 0.62rem;
}

.app-footer {
  grid-row: 4;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 4px 14px;
  overflow: hidden;
  color: #60706c;
  background: var(--reader-bg);
  font-size: 0.63rem;
  text-align: center;
}

.app-footer p {
  margin: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.app-footer button {
  flex: 0 0 auto;
  padding: 0;
  border: 0;
  color: var(--reader-primary-dark);
  background: transparent;
  font-weight: 700;
  text-decoration: underline;
}

.app-dialog {
  position: fixed;
  inset: 0;
  margin: auto;
  width: min(calc(100vw - 24px), 560px);
  max-width: calc(100vw - 24px);
  max-height: min(88dvh, 780px);
  padding: 0;
  overflow-x: hidden;
  overflow-y: auto;
  border: 1px solid var(--reader-line);
  border-radius: 14px;
  color: var(--reader-ink);
  background: var(--reader-surface);
  box-shadow: 0 24px 70px rgba(18, 45, 41, 0.28);
  box-sizing: border-box;
}

.app-dialog::backdrop {
  background: rgba(12, 28, 26, 0.6);
  backdrop-filter: blur(2px);
}

.app-dialog--wide {
  width: min(calc(100vw - 28px), 920px);
  max-height: min(calc(100dvh - 12px), 860px);
}

.app-dialog--small {
  width: min(calc(100vw - 28px), 420px);
}

.app-dialog--confirm {
  width: min(calc(100vw - 28px), 520px);
  overflow: hidden;
  border-top: 4px solid var(--reader-primary);
}

.app-dialog--confirm[data-tone="danger"] {
  border-top-color: var(--reader-danger);
}

.app-dialog--confirm[open] {
  animation: confirmation-dialog-in 180ms ease-out both;
}

.app-dialog form {
  margin: 0;
}

.dialog-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 66px;
  padding: 12px 14px 11px 18px;
  border-bottom: 1px solid var(--reader-line);
}

.dialog-heading > div {
  min-width: 0;
  flex: 1 1 auto;
}

.dialog-heading h2 {
  margin: 0;
  color: var(--reader-ink);
  font-size: 1.08rem;
  font-weight: 700;
  line-height: 1.3;
  overflow-wrap: break-word;
  word-break: normal;
  white-space: normal;
}

.dialog-content {
  padding: 18px;
  overflow-wrap: break-word;
  word-break: normal;
  box-sizing: border-box;
}

.dialog-actions {
  justify-content: flex-end;
  min-height: 68px;
  padding: 11px 18px;
  border-top: 1px solid var(--reader-line);
  background: var(--reader-surface-soft);
}

.dialog-actions--space-between {
  justify-content: space-between;
}

.confirmation-heading {
  padding-top: 14px;
}

.confirmation-content {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  align-items: start;
  gap: 15px;
  padding-block: 22px;
}

.confirmation-icon {
  display: grid;
  width: 52px;
  height: 52px;
  place-items: center;
  border: 1px solid #a9d0c7;
  border-radius: 13px;
  color: var(--reader-primary-dark);
  background: var(--reader-primary-soft);
  box-shadow: 0 5px 14px rgba(18, 104, 88, 0.1);
  font-size: 1.25rem;
}

.app-dialog--confirm[data-tone="danger"] .confirmation-icon {
  border-color: #e8b7c2;
  color: var(--reader-danger);
  background: #fff2f5;
  box-shadow: 0 5px 14px rgba(180, 35, 67, 0.09);
}

.confirmation-copy > p {
  margin: 1px 0 0;
  color: #334743;
  font-size: 0.9rem;
  line-height: 1.58;
}

.confirmation-note {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  margin-top: 14px;
  padding: 11px 12px;
  border-left: 3px solid var(--reader-primary);
  border-radius: 0 8px 8px 0;
  color: #52645f;
  background: var(--reader-surface-soft);
}

.app-dialog--confirm[data-tone="danger"] .confirmation-note {
  border-left-color: var(--reader-danger);
}

.confirmation-note i {
  flex: 0 0 auto;
  margin-top: 2px;
  color: var(--reader-primary-dark);
}

.app-dialog--confirm[data-tone="danger"] .confirmation-note i {
  color: var(--reader-danger);
}

.confirmation-note p {
  margin: 0;
  font-size: 0.78rem;
  line-height: 1.5;
}

.confirmation-actions {
  justify-content: space-between;
  gap: 12px;
}

.confirmation-support {
  flex: 0 0 auto;
}

.confirmation-actions__decision {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  margin-left: auto;
}

@keyframes confirmation-dialog-in {
  from {
    opacity: 0;
    transform: translateY(8px) scale(0.985);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.privacy-copy {
  color: #3f514d;
  font-size: 0.84rem;
  line-height: 1.65;
  overflow-wrap: break-word;
  word-break: normal;
}

.privacy-copy p {
  margin: 10px 0;
}

.privacy-copy p:first-child {
  margin-top: 0;
}

.privacy-copy p:last-child {
  margin-bottom: 0;
}

.privacy-copy ul {
  padding-left: 20px;
  margin: 12px 0;
}

.privacy-copy li + li {
  margin-top: 6px;
}

.metadata-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.metadata-grid label,
.position-editor-options label,
.app-dialog > form > .dialog-content > label {
  display: grid;
  gap: 6px;
  color: #3b4d49;
  font-size: 0.73rem;
  font-weight: 700;
}

.field-span-2 {
  grid-column: 1 / -1;
}

.metadata-grid input,
.metadata-grid select,
.position-editor-options input,
.position-editor-options select,
.app-dialog > form > .dialog-content > label input {
  width: 100%;
  min-height: 42px;
  border: 1px solid var(--reader-line-strong);
  border-radius: 7px;
  padding: 7px 9px;
  background: var(--reader-surface);
  font-size: 0.8rem;
}

.position-editor-layout {
  display: grid;
  grid-template-columns: minmax(300px, 1fr) minmax(260px, 0.8fr);
  gap: 20px;
}

.position-editor-visual {
  min-width: 0;
}

.position-editor-board {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 1;
  margin: 0 auto;
  overflow: visible;
  border: 1px solid #71817d;
  border-radius: 7px;
  background: var(--reader-board-light);
}

.board-coordinate-frame--editor {
  width: min(100%, calc(480px + var(--reader-coord-inline)));
  margin: 0 auto;
}

.position-piece-palette button {
  display: grid;
  min-width: 0;
  min-height: 0;
  place-items: center;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
}

.position-editor-board square.selected {
  background: rgba(255, 196, 0, 0.62);
}

.position-piece-palette img {
  width: 88%;
  height: 88%;
  object-fit: contain;
}

.position-piece-palette {
  display: grid;
  grid-template-columns: repeat(7, minmax(34px, 1fr));
  gap: 4px;
  width: min(100%, 480px);
  margin: 10px auto 0;
}

.position-piece-palette button {
  aspect-ratio: 1;
  border: 1px solid var(--reader-line);
  border-radius: 6px;
  background: var(--reader-surface);
}

.position-piece-palette button[aria-pressed="true"] {
  border: 2px solid var(--reader-primary-dark);
  background: var(--reader-primary-soft);
}

.position-editor-options {
  display: grid;
  align-content: start;
  gap: 14px;
}

.form-row--split {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.castling-options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px 12px;
  margin: 0;
  padding: 12px;
  border: 1px solid var(--reader-line);
  border-radius: 8px;
}

.castling-options legend {
  padding: 0 5px;
  font-size: 0.72rem;
  font-weight: 700;
}

.castling-options label {
  display: flex;
  grid-template: none;
  align-items: center;
  gap: 7px;
  font-weight: 500;
}

.castling-options input {
  width: 16px;
  min-height: 16px;
}

.advanced-fen {
  border: 1px solid var(--reader-line);
  border-radius: 8px;
  padding: 10px;
  background: var(--reader-surface-soft);
}

.advanced-fen summary {
  color: var(--reader-primary-dark);
  font-size: 0.75rem;
  font-weight: 700;
}

.advanced-fen[open] summary {
  margin-bottom: 10px;
}

.advanced-fen textarea {
  width: 100%;
  margin: 6px 0 8px;
  font-family: ui-monospace, "Cascadia Mono", "Segoe UI Mono", monospace;
}

.inline-message,
.field-help {
  min-height: 18px;
  margin: 0;
  color: var(--reader-muted);
  font-size: 0.68rem;
  line-height: 1.45;
}

.board-status.is-error,
.inline-message.is-error {
  color: var(--reader-danger);
}

.position-piece-button--erase,
.position-piece-button--pointer {
  padding: 3px !important;
  font-size: clamp(0.55rem, 1.7vw, 0.7rem);
  font-weight: 700;
  line-height: 1.05;
  text-align: center;
  overflow-wrap: anywhere;
}

.position-piece-button--erase {
  color: var(--reader-danger);
}

.position-piece-button--pointer {
  color: var(--reader-primary-dark);
}

.position-piece-button--erase img,
.position-piece-button--pointer img {
  width: 58%;
  height: 58%;
}

.position-editor-quick-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.promotion-options {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  padding: 18px;
}

.promotion-options button {
  display: grid;
  aspect-ratio: 1;
  place-items: center;
  border: 1px solid var(--reader-line);
  border-radius: 9px;
  background: var(--reader-surface-soft);
}

.promotion-options button:hover,
.promotion-options button:focus-visible {
  border-color: var(--reader-primary);
  background: var(--reader-primary-soft);
}

.promotion-options img {
  width: 88%;
  height: 88%;
  object-fit: contain;
}

.reader-app[data-maximized="pdf"] .study-workspace,
.reader-app[data-maximized="chess"] .study-workspace {
  grid-template-columns: minmax(0, 1fr) !important;
  grid-template-rows: minmax(0, 1fr) !important;
}

.reader-app[data-maximized="pdf"] .pdf-panel,
.reader-app[data-maximized="chess"] .chess-panel {
  grid-column: 1;
  grid-row: 1;
}

.reader-app[data-maximized="pdf"] .workspace-divider,
.reader-app[data-maximized="pdf"] .chess-panel,
.reader-app[data-maximized="chess"] .workspace-divider,
.reader-app[data-maximized="chess"] .pdf-panel {
  display: none;
}

@container chess-panel (min-width: 720px) {
  .chess-workspace {
    display: grid;
    grid-template-columns: minmax(336px, 1fr) minmax(250px, 0.55fr);
    gap: 12px;
  }

  .study-notes {
    margin-top: 0;
  }
}

@media (max-width: 1180px) and (orientation: landscape) {
  :root {
    --reader-split: 52%;
  }

  .panel-toolbar {
    gap: 3px;
  }

  .pdf-search {
    min-width: 150px;
  }

  .search-field {
    min-width: 130px;
  }
}

@media (max-height: 800px) and (min-width: 641px) {
  .player-label {
    display: none;
  }

  .board-column {
    width: min(100%, 680px, calc(100dvh - 345px));
  }

  .board-status {
    min-height: 27px;
  }
}

@media (max-width: 1024px) and (orientation: portrait) and (min-width: 641px) {
  .study-workspace {
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: minmax(330px, 52fr) 12px minmax(390px, 48fr);
  }

  .pdf-panel,
  .workspace-divider,
  .chess-panel {
    grid-column: 1;
  }

  .pdf-panel {
    grid-row: 1;
  }

  .workspace-divider {
    grid-row: 2;
  }

  .chess-panel {
    grid-row: 3;
  }

  .workspace-divider {
    cursor: row-resize;
  }

  .workspace-divider__handle {
    width: 52px;
    height: 7px;
  }

  .workspace-divider__handle i::before {
    content: "\f7a4";
  }

  body.is-resizing,
  body.is-resizing * {
    cursor: row-resize !important;
  }

  .chess-workspace {
    display: grid;
    grid-template-columns: minmax(330px, 0.8fr) minmax(260px, 1fr);
    gap: 12px;
  }

  .board-column {
    align-self: start;
  }

  .study-notes {
    margin-top: 0;
  }

  .reader-app[data-maximized="pdf"] .study-workspace,
  .reader-app[data-maximized="chess"] .study-workspace {
    grid-template-rows: minmax(0, 1fr);
  }
}

@media (max-width: 760px) {
  :root {
    --reader-header-height: 60px;
    --reader-footer-height: 0px;
  }

  .app-header {
    padding-inline: 10px;
  }

  .brand__logo {
    width: 42px;
    height: 42px;
    flex-basis: 42px;
  }

  .save-status span {
    display: none;
  }

  .save-status {
    width: 38px;
    min-height: 38px;
    justify-content: center;
    padding: 0;
  }

  .app-footer {
    display: none;
  }

  .position-editor-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px), (max-height: 600px) and (pointer: coarse) {
  :root {
    --reader-tab-height: 46px;
  }

  .reader-app {
    grid-template-rows: var(--reader-header-height) var(--reader-tab-height) minmax(0, 1fr);
  }

  .app-footer {
    display: none;
  }

  .mobile-panel-tabs {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    padding: 4px;
    border-bottom: 1px solid var(--reader-line);
    background: var(--reader-surface);
  }

  .mobile-panel-tab {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-height: 38px;
    border: 0;
    border-radius: 7px;
    color: var(--reader-muted);
    background: transparent;
    font-size: 0.8rem;
    font-weight: 700;
  }

  .mobile-panel-tab.is-active {
    color: var(--reader-primary-dark);
    background: var(--reader-primary-soft);
  }

  .study-workspace {
    display: block;
    padding: 5px;
  }

  .workspace-divider {
    display: none;
  }

  .study-panel {
    height: 100%;
    border-radius: 9px;
  }

  .reader-app[data-active-panel="pdf"] .chess-panel,
  .reader-app[data-active-panel="chess"] .pdf-panel {
    display: none;
  }

  .reader-app[data-maximized] .mobile-panel-tabs {
    display: none;
  }

  .reader-app[data-maximized] {
    --reader-tab-height: 0px;
  }

  .panel-heading {
    min-height: 57px;
    padding: 7px 8px 7px 12px;
  }

  .panel-title-group h1,
  .panel-title-group h2 {
    max-width: 52vw;
    font-size: 0.9rem;
  }

  .panel-toolbar {
    min-height: 48px;
    padding: 4px;
  }

  .icon-button {
    width: 42px;
    min-width: 42px;
    min-height: 42px;
  }

  .button--compact {
    min-height: 40px;
  }

  .pdf-search {
    min-width: 158px;
  }

  .chess-workspace {
    padding: 6px;
  }

  .board-column {
    width: min(100%, calc(100dvh - 262px));
    min-width: 282px;
  }

  .study-notes {
    min-height: 360px;
  }

  .panel-footnote,
  .panel-status {
    min-height: 27px;
  }
}

@media (max-width: 560px) {
  .confirmation-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .confirmation-support,
  .confirmation-actions__decision,
  .confirmation-actions__decision .button {
    width: 100%;
  }

  .confirmation-actions__decision {
    flex-direction: column;
    margin-left: 0;
  }

  .confirmation-actions__decision .button--danger,
  .confirmation-actions__decision .button--primary {
    order: 2;
  }
}

@media (max-width: 430px) {
  .brand__copy span {
    display: none;
  }

  .brand__copy strong {
    max-width: 165px;
    overflow: hidden;
    font-size: 0.92rem;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .panel-heading-actions .button span {
    display: none;
  }

  .panel-heading-actions .button {
    width: 42px;
    min-width: 42px;
    padding: 0;
  }

  .empty-state {
    padding: 18px 13px;
  }

  .pdf-drop-zone {
    padding: 18px 12px;
  }

  .metadata-grid,
  .form-row--split,
  .castling-options {
    grid-template-columns: 1fr;
  }

  .dialog-actions--space-between {
    align-items: stretch;
    flex-direction: column;
  }

  .dialog-actions--space-between > div {
    justify-content: flex-end;
  }

  .confirmation-content {
    grid-template-columns: 46px minmax(0, 1fr);
    gap: 12px;
    padding: 18px 14px;
  }

  .confirmation-icon {
    width: 44px;
    height: 44px;
    border-radius: 11px;
    font-size: 1.05rem;
  }

  .header-status {
    gap: 6px;
  }

  .app-dialog {
    width: min(calc(100vw - 16px), 560px);
    max-width: calc(100vw - 16px);
    border-radius: 12px;
  }

  .dialog-heading {
    padding: 10px 12px 9px 14px;
    min-height: 56px;
  }

  .dialog-heading h2 {
    font-size: 0.98rem;
  }

  .dialog-content {
    padding: 14px;
  }

  .privacy-copy {
    font-size: 0.82rem;
    line-height: 1.55;
  }

  .privacy-copy ul {
    padding-left: 18px;
    margin: 10px 0;
  }

  .dialog-actions {
    min-height: 58px;
    padding: 10px 14px;
  }

}

@media (prefers-reduced-motion: reduce) {
  .app-dialog--confirm[open] {
    animation: none;
  }
}

/* Biblioteca de estudio: continuidad local y Premium sin interferir con el Atril. */
.button--library {
  position: relative;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.1);
  box-shadow: none;
}

.button--library:hover {
  border-color: rgba(255, 255, 255, 0.5);
  background: rgba(255, 255, 255, 0.17);
}

.library-count-badge,
.reader-access-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 22px;
  padding: 2px 7px;
  border-radius: 999px;
  color: var(--reader-primary-dark);
  background: var(--reader-surface);
  font-size: 0.68rem;
  font-weight: 800;
  line-height: 1;
  white-space: nowrap;
}

.app-dialog--library {
  width: min(calc(100vw - 28px), 1120px);
  height: min(calc(100dvh - 28px), 820px);
  max-height: none;
  overflow: hidden;
}

.reader-library-shell {
  display: grid;
  grid-template-rows: auto auto auto auto minmax(0, 1fr) auto;
  height: 100%;
  min-height: 0;
}

.reader-library-heading {
  background: linear-gradient(120deg, #fff 0%, #f3fbf8 100%);
}

.reader-library-heading__actions,
.reader-library-toolbar,
.reader-library-filters,
.reader-library-summary {
  display: flex;
  align-items: center;
}

.reader-library-heading__actions {
  gap: 9px;
}

.reader-access-pill {
  min-height: 28px;
  color: #fff;
  background: var(--reader-primary-dark);
}

.reader-access-pill[data-tier="premium"] {
  color: #563e03;
  background: #f4cf68;
}

.reader-access-pill[data-tier="sandbox"] {
  color: #fff;
  background: #7b4aa8;
}

.reader-library-toolbar {
  position: relative;
  z-index: 4;
  gap: 8px;
  min-height: 60px;
  padding: 8px 16px;
  border-bottom: 1px solid var(--reader-line);
  background: var(--reader-surface);
}

.reader-library-more .compact-menu__surface {
  right: 0;
  left: auto;
}

.reader-library-more.compact-menu {
  display: block;
}

.reader-library-filters {
  gap: 10px;
  padding: 11px 16px;
  border-bottom: 1px solid var(--reader-line);
  background: var(--reader-surface-soft);
}

.reader-library-filters[hidden],
.reader-library-toolbar[hidden],
.reader-library-summary[hidden],
.reader-library-toolbar > [hidden],
.reader-library-summary > [hidden] {
  display: none !important;
}

.reader-library-search {
  width: min(100%, 620px);
  min-width: 0;
}

.reader-library-search input {
  width: 100%;
}

.reader-library-filter-label select {
  min-height: 38px;
  padding: 5px 32px 5px 10px;
  border: 1px solid var(--reader-line-strong);
  border-radius: 8px;
  background: var(--reader-surface);
  font-size: 0.78rem;
}

.reader-library-summary {
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 14px;
  min-height: 42px;
  padding: 8px 16px;
  border-bottom: 1px solid var(--reader-line);
  color: var(--reader-muted);
  font-size: 0.76rem;
}

.reader-library-summary p {
  margin: 0;
}

.reader-premium-link {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 4px 0;
  border: 0;
  color: var(--reader-primary-dark);
  background: transparent;
  font-size: inherit;
  font-weight: 800;
  text-decoration: underline;
}

.reader-library-content {
  min-height: 0;
  overflow: auto;
  overscroll-behavior: contain;
  padding: 16px;
  background: #f5f3ed;
}

.reader-library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(245px, 1fr));
  align-items: stretch;
  gap: 14px;
}

.reader-library-load-more {
  display: flex;
  width: fit-content;
  min-height: 44px;
  margin: 16px auto 2px;
}

.reader-library-load-more[hidden] {
  display: none;
}

.reader-book-card {
  display: grid;
  grid-template-columns: 82px minmax(0, 1fr);
  gap: 13px;
  min-height: 154px;
  padding: 12px;
  overflow: hidden;
  border: 1px solid var(--reader-line);
  border-radius: 12px;
  background: var(--reader-surface);
  box-shadow: 0 3px 12px rgba(24, 48, 45, 0.07);
}

.reader-book-card.is-active {
  border-color: var(--reader-primary);
  box-shadow: 0 0 0 2px rgba(26, 142, 120, 0.12), 0 8px 22px rgba(24, 48, 45, 0.1);
}

.reader-book-cover {
  position: relative;
  display: grid;
  width: 82px;
  min-height: 112px;
  overflow: hidden;
  place-items: center;
  border-radius: 7px 9px 9px 7px;
  color: #fff;
  background: linear-gradient(145deg, #173f3a, #1a8e78);
  box-shadow: inset 5px 0 0 rgba(255, 255, 255, 0.1), 0 5px 13px rgba(24, 48, 45, 0.18);
}

.reader-book-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.reader-book-cover i {
  font-size: 1.45rem;
}

.reader-book-card__body {
  display: flex;
  min-width: 0;
  flex-direction: column;
}

.reader-book-card__eyebrow,
.reader-book-card__meta,
.reader-book-card__progress-label {
  color: var(--reader-muted);
  font-size: 0.68rem;
}

.reader-book-card h3 {
  display: -webkit-box;
  margin: 4px 0;
  overflow: hidden;
  font-size: 0.88rem;
  line-height: 1.3;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.reader-book-card__author {
  margin: 0;
  overflow: hidden;
  color: #48605b;
  font-size: 0.72rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.reader-book-card__progress {
  height: 5px;
  margin: 9px 0 4px;
  overflow: hidden;
  border-radius: 99px;
  background: #e5ece9;
}

.reader-book-card__progress > span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--reader-primary);
}

.reader-book-card__actions {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: auto;
  padding-top: 9px;
}

.reader-book-card__actions button {
  min-height: 36px;
  padding-inline: 10px;
  font-size: 0.72rem;
}

.reader-book-card__actions .icon-button {
  width: 36px;
  min-width: 36px;
  padding: 0;
}

.reader-library-empty {
  display: grid;
  width: min(100%, 560px);
  min-height: 300px;
  margin: 0 auto;
  padding: 28px;
  place-items: center;
  align-content: center;
  text-align: center;
}

.reader-current-reading {
  display: grid;
  grid-template-columns: 112px minmax(0, 1fr);
  gap: 18px;
  width: min(100%, 720px);
  margin: 0 auto 16px;
  padding: 16px;
  border: 1px solid #b9d8d1;
  border-radius: 14px;
  background: linear-gradient(135deg, #fff 0%, #f0faf7 100%);
  box-shadow: 0 8px 24px rgba(24, 48, 45, 0.09);
}

.reader-current-reading[hidden] {
  display: none;
}

.reader-current-reading.is-saved {
  border-color: var(--reader-primary);
}

.reader-current-reading__cover {
  display: grid;
  width: 112px;
  aspect-ratio: 0.72;
  overflow: hidden;
  place-items: center;
  align-self: start;
  border-radius: 7px 10px 10px 7px;
  color: #fff;
  background: linear-gradient(145deg, #173f3a, #1a8e78);
  box-shadow: inset 6px 0 0 rgba(255, 255, 255, 0.1), 0 6px 16px rgba(24, 48, 45, 0.2);
}

.reader-current-reading__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: var(--reader-surface);
}

.reader-current-reading__cover i {
  font-size: 2rem;
}

.reader-current-reading__cover.is-loading {
  background: linear-gradient(145deg, #173f3a, #287469);
}

.reader-current-reading__body {
  display: flex;
  min-width: 0;
  flex-direction: column;
  justify-content: center;
}

.reader-current-reading h3 {
  margin: 4px 0 3px;
  overflow: hidden;
  font-size: 1.04rem;
  line-height: 1.3;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.reader-current-reading__status,
.reader-current-reading__page {
  margin: 0;
  color: var(--reader-muted);
  font-size: 0.73rem;
}

.reader-current-reading__progress {
  height: 6px;
  margin: 12px 0 5px;
  overflow: hidden;
  border-radius: 99px;
  background: #dfeae7;
}

.reader-current-reading__progress > span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--reader-primary);
}

.reader-current-reading__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.reader-current-reading__actions .button {
  min-height: 44px;
}

.reader-detail-badges .is-device-needed {
  color: #586d68;
  background: #edf1ef;
}

.reader-library-empty__icon {
  display: grid;
  width: 74px;
  height: 74px;
  place-items: center;
  border-radius: 22px;
  color: var(--reader-primary-dark);
  background: var(--reader-primary-soft);
  font-size: 1.7rem;
}

.reader-library-empty h3 {
  margin: 17px 0 7px;
  font-size: 1.06rem;
}

.reader-library-empty p {
  max-width: 500px;
  margin: 0 0 18px;
  color: var(--reader-muted);
  font-size: 0.84rem;
  line-height: 1.55;
}

.reader-empty-restore {
  min-height: 44px;
  padding: 8px 4px;
  border: 0;
  color: var(--reader-primary-dark);
  background: transparent;
  font: inherit;
  font-size: 0.76rem;
  font-weight: 750;
  text-decoration: underline;
  cursor: pointer;
}

.reader-library-detail {
  padding: 14px;
  border: 1px solid var(--reader-line);
  border-radius: 12px;
  background: var(--reader-surface);
}

.reader-library-status {
  min-height: 36px;
  padding: 8px 16px;
  border-top: 1px solid var(--reader-line);
  color: var(--reader-muted);
  background: var(--reader-surface);
  font-size: 0.73rem;
}

.reader-book-form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.reader-book-form-grid label {
  display: grid;
  gap: 6px;
  color: #3b4d49;
  font-size: 0.73rem;
  font-weight: 700;
}

.reader-book-form-grid input,
.reader-book-form-grid select {
  width: 100%;
  min-height: 42px;
  padding: 7px 9px;
  border: 1px solid var(--reader-line-strong);
  border-radius: 7px;
  background: var(--reader-surface);
}

.reader-cache-choice {
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  padding: 12px;
  border: 1px solid #cfe0dc;
  border-radius: 9px;
  background: var(--reader-primary-soft);
}

.reader-cache-choice input {
  width: 18px;
  min-height: 18px;
  margin-top: 2px;
}

.reader-cache-choice span {
  display: grid;
  gap: 3px;
}

.reader-cache-choice small {
  color: var(--reader-muted);
  font-weight: 500;
  line-height: 1.45;
}

.reader-field-premium {
  display: inline-flex;
  width: fit-content;
  margin-left: 4px;
  padding: 2px 6px;
  border-radius: 999px;
  color: #72520a;
  background: #f8e8b9;
  font-size: 0.6rem;
  font-weight: 800;
  line-height: 1.2;
}

[data-reader-premium-field].is-premium-locked {
  cursor: pointer;
}

[data-reader-premium-field].is-premium-locked input,
[data-reader-premium-field].is-premium-locked select {
  color: #71817d;
  background: #f3f5f4;
  cursor: pointer;
}

.reader-favorite-choice {
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  align-self: end;
  min-height: 42px;
  padding: 8px 10px;
  border: 1px solid var(--reader-line-strong);
  border-radius: 7px;
  background: var(--reader-surface);
}

.reader-favorite-choice input {
  width: 18px;
  min-height: 18px;
}

.reader-favorite-choice small {
  margin-left: 5px;
  color: #72520a;
  font-size: 0.62rem;
}

.reader-detail-heading,
.reader-detail-section__heading,
.reader-detail-item,
.reader-detail-item__actions,
.reader-detail-actions,
.reader-detail-badges {
  display: flex;
  align-items: center;
}

.reader-detail-heading {
  gap: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--reader-line);
}

.reader-detail-heading__title {
  min-width: 0;
  flex: 1;
}

.reader-detail-heading__title h3 {
  margin: 2px 0;
  overflow-wrap: anywhere;
}

.reader-detail-heading__title p {
  margin: 0;
  color: var(--reader-muted);
  font-size: 0.75rem;
}

.reader-detail-badges {
  flex-wrap: wrap;
  gap: 6px;
  padding: 12px 0;
}

.reader-detail-badges span {
  padding: 4px 8px;
  border-radius: 999px;
  color: #3d5550;
  background: #edf2f0;
  font-size: 0.67rem;
  font-weight: 700;
}

.reader-detail-badges .is-tag {
  color: var(--reader-primary-dark);
  background: var(--reader-primary-soft);
}

.reader-detail-section {
  padding: 13px 0;
  border-top: 1px solid var(--reader-line);
}

.reader-detail-partidas {
  padding: 0;
}

.reader-detail-partidas > summary {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 0 2px;
  color: var(--reader-primary-dark);
  font-weight: 800;
  cursor: pointer;
}

.reader-detail-partidas > summary::marker {
  color: var(--reader-primary);
}

.reader-detail-partidas[open] > summary {
  border-bottom: 1px solid var(--reader-line);
}

.reader-detail-partidas__body {
  padding: 13px 0 2px;
}

.reader-detail-download-pgn {
  margin-top: 8px;
}

.reader-detail-section__heading {
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 9px;
}

.reader-detail-section__heading h4 {
  margin: 0;
  font-size: 0.88rem;
}

.reader-detail-list {
  display: grid;
  gap: 7px;
}

.reader-detail-item {
  justify-content: space-between;
  gap: 12px;
  min-height: 54px;
  padding: 9px 10px;
  border: 1px solid var(--reader-line);
  border-radius: 8px;
  background: var(--reader-surface-soft);
}

.reader-detail-item.is-active {
  border-color: #91c8bd;
  background: var(--reader-primary-soft);
}

.reader-detail-item > div:first-child {
  display: grid;
  min-width: 0;
  gap: 3px;
}

.reader-detail-item strong {
  overflow-wrap: anywhere;
  font-size: 0.76rem;
}

.reader-detail-item small,
.reader-detail-empty {
  color: var(--reader-muted);
  font-size: 0.67rem;
}

.reader-detail-item__actions {
  flex: 0 0 auto;
  gap: 6px;
}

.reader-detail-item__actions .icon-button {
  width: 38px;
  min-width: 38px;
  min-height: 38px;
}

.reader-detail-empty {
  margin: 0;
  padding: 14px;
  border: 1px dashed var(--reader-line-strong);
  border-radius: 8px;
  text-align: center;
}

.reader-detail-actions {
  flex-wrap: wrap;
  gap: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--reader-line);
}

.reader-danger-link {
  margin-left: auto;
  color: var(--reader-danger) !important;
}

.reader-library-status[data-tone="error"],
.inline-message[data-tone="error"] {
  color: #9d1733;
}

.reader-library-status[data-tone="success"],
.inline-message[data-tone="success"] {
  color: #0d715d;
}

.reader-toast[data-tone="error"] {
  border-color: #d798a6;
  background: #8f1832;
}

.app-dialog--premium {
  width: min(calc(100vw - 28px), 680px);
  max-height: min(92dvh, 820px);
  overflow-x: hidden;
  overflow-y: auto;
  border-top: 5px solid #d6a82a;
}

.reader-premium-heading {
  background: linear-gradient(120deg, #fffdf7, #f8f1dd);
}

.reader-premium-shell,
.reader-premium-heading > div,
.reader-premium-content,
.reader-premium-content > * {
  min-width: 0;
  max-width: 100%;
}

.reader-premium-heading h2 {
  overflow: visible;
  text-overflow: clip;
  white-space: normal;
  overflow-wrap: anywhere;
}

.reader-premium-content {
  display: grid;
  gap: 16px;
}

.reader-premium-price {
  display: grid;
  padding: 17px;
  border: 1px solid #e8d39a;
  border-radius: 12px;
  color: #4a390c;
  background: linear-gradient(145deg, #fffdf7, #f8edce);
  text-align: center;
}

.reader-premium-price span,
.reader-premium-price small {
  font-size: 0.74rem;
  font-weight: 700;
}

.reader-premium-price strong {
  margin: 3px 0;
  color: #173f3a;
  font-size: clamp(2rem, 8vw, 2.8rem);
  letter-spacing: -0.04em;
}

.reader-premium-benefits {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.reader-premium-benefits li {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  padding: 11px;
  border: 1px solid var(--reader-line);
  border-radius: 9px;
  color: #334743;
  font-size: 0.79rem;
  line-height: 1.45;
}

.reader-premium-benefits i {
  margin-top: 2px;
  color: var(--reader-primary);
}

.reader-premium-privacy,
.reader-premium-account {
  margin: 0;
  padding: 12px 13px;
  border-radius: 9px;
  font-size: 0.78rem;
  line-height: 1.5;
}

.reader-premium-privacy {
  display: flex;
  gap: 9px;
  color: #31524b;
  background: var(--reader-primary-soft);
}

.reader-premium-account {
  color: #52645f;
  background: var(--reader-surface-soft);
}

.reader-terms-choice {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  color: #3b4d49;
  font-size: 0.76rem;
  line-height: 1.45;
}

.reader-terms-choice input {
  width: 18px;
  height: 18px;
  flex: 0 0 18px;
}

.reader-terms-choice a {
  color: var(--reader-primary-dark);
  font-weight: 700;
}

.reader-paypal {
  min-height: 84px;
}

.reader-premium-actions {
  justify-content: space-between;
}

.reader-toast {
  position: fixed;
  z-index: 200;
  right: max(16px, var(--reader-safe-right, env(safe-area-inset-right)));
  bottom: max(16px, var(--reader-safe-bottom, env(safe-area-inset-bottom)));
  max-width: min(420px, calc(100vw - 32px));
  padding: 12px 15px;
  border: 1px solid #8dc3b7;
  border-radius: 10px;
  color: #fff;
  background: #173f3a;
  box-shadow: var(--reader-shadow);
  font-size: 0.79rem;
  line-height: 1.45;
}

@media (max-width: 760px) {
  .button--library {
    width: 42px;
    min-width: 42px;
    padding: 0;
  }

  .button--library > span {
    display: none;
  }

  .button--library .library-count-badge {
    position: absolute;
    top: -3px;
    right: -4px;
    display: inline-flex;
    min-width: 20px;
    min-height: 20px;
    padding: 2px 4px;
    font-size: 0.6rem;
  }

  .app-dialog--library {
    width: 100vw;
    height: 100dvh;
    max-height: none;
    margin: 0;
    border: 0;
    border-radius: 0;
  }

  .reader-library-toolbar {
    overflow: visible;
    flex-wrap: nowrap;
    gap: 6px;
    padding-inline: 10px;
  }

  .reader-library-toolbar::-webkit-scrollbar {
    display: none;
  }

  .reader-library-toolbar .button span,
  .reader-library-toolbar > .text-button span {
    display: none;
  }

  .reader-library-toolbar .button {
    width: 42px;
    min-width: 42px;
    padding: 0;
  }

  .reader-library-toolbar > [data-reader-action="save-current-book"],
  .reader-library-toolbar > [data-reader-action="add-study"] {
    width: auto;
    min-width: 44px;
    min-height: 44px;
    padding-inline: 11px;
    white-space: nowrap;
  }

  .reader-library-toolbar > [data-reader-action="save-current-book"] span,
  .reader-library-toolbar > [data-reader-action="add-study"] span {
    display: inline;
  }

  .reader-library-more > summary {
    white-space: nowrap;
  }

  .reader-library-filters {
    padding: 8px 10px;
  }

  .reader-library-filter-label select {
    width: 108px;
  }

  .reader-library-grid {
    grid-template-columns: 1fr;
  }

  .reader-premium-benefits,
  .reader-book-form-grid {
    grid-template-columns: 1fr;
  }

  .reader-book-form-grid .field-span-2 {
    grid-column: auto;
  }

  .reader-detail-heading {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .reader-detail-heading__title {
    min-width: calc(100% - 110px);
  }

  .reader-detail-item {
    align-items: flex-start;
    flex-direction: column;
  }

  .reader-detail-item__actions {
    width: 100%;
    justify-content: flex-end;
  }
}

@media (max-width: 430px) {
  .reader-library-heading {
    padding-left: 13px;
  }

  .reader-library-heading__actions .reader-access-pill {
    display: none;
  }

  .reader-library-summary {
    align-items: flex-start;
    flex-direction: column;
    gap: 4px;
  }

  .reader-library-content {
    padding: 10px;
  }

  .reader-current-reading {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 12px;
    padding: 12px;
  }

  .reader-current-reading__cover {
    width: 84px;
  }

  .reader-current-reading h3 {
    font-size: 0.92rem;
  }

  .reader-current-reading__actions {
    align-items: stretch;
    flex-direction: column;
  }

  .reader-current-reading__actions .button {
    width: 100%;
  }

  .reader-book-card {
    grid-template-columns: 72px minmax(0, 1fr);
  }

  .reader-book-cover {
    width: 72px;
  }

  .reader-premium-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .reader-premium-actions .button {
    width: 100%;
  }

  .reader-premium-heading {
    align-items: flex-start;
    gap: 8px;
  }

  .reader-premium-content {
    padding: 14px;
  }

  .reader-premium-benefits {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-height: 600px) and (pointer: coarse) {
  :root {
    --reader-header-height: 52px;
  }

  .brand__logo {
    width: 38px;
    height: 38px;
    flex-basis: 38px;
  }

  .panel-heading {
    min-height: 51px;
  }

  .panel-kicker,
  .panel-footnote {
    display: none;
  }

  .board-column {
    width: min(100%, calc(100dvh - 214px));
  }
}

/* Modo Estudio Continuo: conserva el libro y el tablero en una sola vista móvil. */
@media (max-width: 640px), (max-height: 600px) and (pointer: coarse) {
  :root {
    --atril-board-size: 320px;
    --atril-divider-size: 12px;
    --reader-tab-height: 46px;
  }

  .reader-app {
    width: 100%;
    height: 100dvh;
    min-height: 100svh;
    padding-right: var(--reader-safe-right, env(safe-area-inset-right));
    padding-left: var(--reader-safe-left, env(safe-area-inset-left));
  }

  .mobile-panel-tabs {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 2px;
    padding: 3px max(4px, var(--reader-safe-right, env(safe-area-inset-right))) 3px max(4px, var(--reader-safe-left, env(safe-area-inset-left)));
  }

  .mobile-panel-tab {
    min-width: 0;
    min-height: 40px;
    gap: 6px;
  }

  .mobile-panel-tab:disabled {
    background: #f2f3f2;
  }

  .reader-app[data-mobile-layout="combined"] {
    grid-template-rows: var(--reader-safe-top, env(safe-area-inset-top)) var(--reader-tab-height) minmax(0, 1fr);
  }

  .reader-app[data-mobile-layout="combined"] > .app-header {
    display: none;
  }

  .reader-app[data-mobile-layout="combined"] .study-workspace {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    grid-template-rows: minmax(160px, 1fr) var(--atril-divider-size) auto;
    min-height: 0;
    padding: 0;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-panel,
  .reader-app[data-mobile-layout="combined"] .workspace-divider,
  .reader-app[data-mobile-layout="combined"] .chess-panel {
    display: grid;
    grid-column: 1;
    min-width: 0;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-panel {
    grid-row: 1;
    grid-template-rows: 44px minmax(0, 1fr);
    border-radius: 0;
  }

  .reader-app[data-mobile-layout="combined"] .workspace-divider {
    position: relative;
    z-index: 12;
    grid-row: 2;
    cursor: row-resize;
  }

  .reader-app[data-mobile-layout="combined"] .workspace-divider::before {
    position: absolute;
    width: 52px;
    height: 44px;
    content: "";
  }

  .reader-app[data-mobile-layout="combined"] .workspace-divider__handle {
    width: 52px;
    height: 7px;
  }

  .reader-app[data-mobile-layout="combined"] .workspace-divider__handle i::before {
    content: "\f7a4";
  }

  .reader-app[data-mobile-layout="combined"] .chess-panel {
    grid-row: 3;
    grid-template-rows: 44px minmax(0, 1fr);
    height: calc(var(--atril-board-size) + 68px + var(--reader-safe-bottom, env(safe-area-inset-bottom)));
    overflow: visible;
    border-radius: 0;
  }

  .reader-app[data-mobile-layout="pdf"] .chess-panel,
  .reader-app[data-mobile-layout="pdf"] .workspace-divider,
  .reader-app[data-mobile-layout="chess"] .pdf-panel,
  .reader-app[data-mobile-layout="chess"] .workspace-divider {
    display: none;
  }

  .reader-app[data-mobile-layout="pdf"] .pdf-panel,
  .reader-app[data-mobile-layout="chess"] .chess-panel {
    display: grid;
  }

  .reader-app[data-mobile-layout="combined"] .panel-heading,
  .reader-app[data-mobile-layout="combined"] .panel-status,
  .reader-app[data-mobile-layout="combined"] .panel-footnote,
  .reader-app[data-mobile-layout="combined"] .player-label,
  .reader-app[data-mobile-layout="combined"] .board-status {
    display: none;
  }

  .reader-app[data-mobile-layout="combined"] .panel-toolbar {
    min-height: 44px;
    max-height: 44px;
    padding: 0 3px;
    overflow: visible;
  }

  .reader-app[data-mobile-layout="combined"] .icon-button,
  .reader-app[data-mobile-layout="combined"] .text-button,
  .reader-app[data-mobile-layout="combined"] .compact-menu > summary,
  .reader-app[data-mobile-layout="combined"] .mobile-study-tray {
    min-height: 44px;
  }

  .reader-app[data-mobile-layout="combined"] .icon-button {
    width: 44px;
    min-width: 44px;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-toolbar {
    position: relative;
    z-index: 20;
    gap: 2px;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .toolbar-group:first-child > [data-action="toggle-thumbnails"],
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .toolbar-group:nth-of-type(2) > [data-action="zoom-out"],
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .toolbar-group:nth-of-type(2) > [data-action="zoom-in"],
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .toolbar-group:nth-of-type(2) > [data-action="fit-page"],
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .toolbar-group:nth-of-type(2) > [data-action="rotate-pdf"],
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .toolbar-separator,
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .toolbar-spacer,
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .pdf-search,
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > [data-action="close-pdf"],
  .reader-app[data-mobile-layout="combined"] .pdf-toolbar .zoom-label {
    display: none;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-toolbar > .toolbar-group:nth-of-type(2) {
    margin-left: auto;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-toolbar .text-button {
    padding-inline: 8px;
  }

  .reader-app[data-mobile-layout="combined"] .compact-menu {
    display: block;
  }

  .reader-app[data-mobile-layout="combined"].has-pdf-compact-menu .pdf-toolbar {
    /* El toolbar es un contexto de apilado: debe quedar sobre el tablero
       mientras su hoja está abierta para que el z-index interno sea efectivo. */
    z-index: 120;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-compact-menu[open]::before {
    position: fixed;
    z-index: 121;
    inset: 0;
    content: "";
    background: rgba(12, 28, 26, 0.42);
  }

  .reader-app[data-mobile-layout="combined"] .pdf-compact-menu[open] > summary {
    position: relative;
    z-index: 123;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-compact-menu .compact-menu__surface {
    z-index: 122;
    top: calc(var(--reader-tab-height) + 46px + var(--reader-safe-top, env(safe-area-inset-top)));
    width: min(360px, calc(100vw - 16px - var(--reader-safe-left, env(safe-area-inset-left)) - var(--reader-safe-right, env(safe-area-inset-right))));
    max-height: calc(100dvh - var(--reader-tab-height) - 58px - var(--reader-safe-top, env(safe-area-inset-top)) - var(--reader-safe-bottom, env(safe-area-inset-bottom)));
    overflow-x: hidden;
    overflow-y: auto;
    overscroll-behavior: contain;
    touch-action: pan-y;
    -webkit-overflow-scrolling: touch;
    border-radius: 14px;
  }

  .reader-app[data-mobile-layout="combined"] .chess-toolbar > :not(.toolbar-group):not(.chess-compact-menu),
  .reader-app[data-mobile-layout="combined"] .chess-toolbar .chess-nav-extended {
    display: none;
  }

  .reader-app[data-mobile-layout="combined"] .chess-toolbar .toolbar-group {
    gap: 4px;
  }

  .reader-app[data-mobile-layout="combined"] .chess-compact-menu {
    margin-left: auto;
  }

  .reader-app[data-mobile-layout="combined"] .chess-compact-menu .compact-menu__surface {
    bottom: max(8px, var(--reader-safe-bottom, env(safe-area-inset-bottom)));
  }

  .reader-app[data-mobile-layout="combined"] .pdf-reader-body,
  .reader-app[data-mobile-layout="combined"] .pdf-stage {
    min-height: 0;
    touch-action: pan-x pan-y;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-stage {
    scrollbar-gutter: auto;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-pages {
    padding: 8px;
  }

  .reader-app[data-mobile-layout="combined"] .chess-workspace {
    position: relative;
    z-index: 22;
    display: block;
    min-height: 0;
    padding: 2px 4px calc(2px + var(--reader-safe-bottom, env(safe-area-inset-bottom)));
    overflow: visible;
    touch-action: manipulation;
  }

  .reader-app[data-mobile-layout="combined"] .board-column {
    position: relative;
    width: min(calc(var(--atril-board-size) + var(--reader-coord-inline) + 8px), calc(100vw - 8px - var(--reader-safe-left, env(safe-area-inset-left)) - var(--reader-safe-right, env(safe-area-inset-right))));
    max-width: 100%;
    min-width: 0;
    margin: 0 auto;
  }

  .reader-app[data-mobile-layout="combined"] .board-shell {
    padding: 0;
    border: 0;
    border-radius: 7px;
  }

  .reader-app[data-mobile-layout="combined"] .chess-board {
    width: 100%;
    max-width: none;
    margin: 0 auto;
  }

  .reader-app[data-mobile-layout="combined"] .board-coordinate-frame {
    width: min(calc(var(--atril-board-size) + var(--reader-coord-inline)), calc(100vw - 16px - var(--reader-safe-left, env(safe-area-inset-left)) - var(--reader-safe-right, env(safe-area-inset-right))), 100%);
    max-width: min(calc(100svh - 52px), calc(100% - 8px));
    margin: 0 auto;
  }

  .reader-app[data-mobile-layout="combined"] .chess-board silicio-board-container {
    width: 100%;
    height: 100%;
  }

  .reader-app[data-mobile-layout="combined"] .chess-board coords.files {
    left: 0;
    bottom: calc(-1 * var(--reader-coord-block));
    width: 100%;
    height: 16px;
  }

  .reader-app[data-mobile-layout="combined"] .chess-board coords.ranks {
    top: 0;
    left: calc(-1 * var(--reader-coord-inline));
  }

  .mobile-study-tray {
    width: 100%;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    margin-top: 2px;
    padding: 0 11px;
    border: 1px solid var(--reader-line);
    border-radius: 8px;
    color: var(--reader-ink);
    background: var(--reader-surface);
    box-shadow: 0 2px 9px rgba(24, 48, 45, 0.08);
    font-size: 0.72rem;
  }

  .reader-app[data-mobile-layout="combined"] .mobile-study-tray,
  .reader-app[data-mobile-layout="chess"] .mobile-study-tray {
    display: flex;
  }

  .reader-app[data-mobile-layout="combined"] .mobile-study-tray {
    position: absolute;
    z-index: 24;
    top: -46px;
    right: 62px;
    left: 100px;
    width: auto;
    height: 44px;
    margin: 0;
    padding-inline: 8px;
    border-color: transparent;
    background: transparent;
    box-shadow: none;
  }

  .reader-app[data-mobile-layout="combined"] .mobile-study-tray__label,
  .reader-app[data-mobile-layout="combined"] .mobile-study-tray > .fa-chevron-up {
    display: none;
  }

  .reader-app[data-mobile-layout="combined"] .mobile-study-tray strong {
    text-align: center;
  }

  .mobile-study-tray__label {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    color: var(--reader-muted);
  }

  .mobile-study-tray strong {
    flex: 1;
    overflow: hidden;
    text-align: right;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .study-notes {
    position: fixed;
    z-index: 80;
    right: var(--reader-safe-right, env(safe-area-inset-right));
    bottom: 0;
    left: var(--reader-safe-left, env(safe-area-inset-left));
    display: grid;
    width: auto;
    height: min(78dvh, 680px);
    min-height: 320px;
    grid-template-rows: auto minmax(150px, 1fr) auto;
    gap: 8px;
    margin: 0;
    padding: 8px 8px max(8px, var(--reader-safe-bottom, env(safe-area-inset-bottom)));
    visibility: hidden;
    border: 1px solid var(--reader-line-strong);
    border-radius: 16px 16px 0 0;
    background: var(--reader-surface-soft);
    box-shadow: 0 -18px 50px rgba(12, 28, 26, 0.28);
    transform: translateY(calc(100% + 18px));
    transition: transform 180ms ease, visibility 180ms;
  }

  .study-notes[data-sheet-state="open"] {
    visibility: visible;
    transform: translateY(0);
  }

  .study-sheet-heading {
    display: flex;
    min-height: 48px;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding: 0 2px 4px 6px;
  }

  .study-sheet-heading h3 {
    margin: 0;
    font-size: 0.88rem;
  }

  .study-sheet-heading .panel-kicker {
    margin-bottom: 2px;
  }

  .study-sheet-heading__actions {
    display: flex;
    align-items: center;
    gap: 1px;
  }

  .study-sheet-heading__actions .icon-button {
    width: 40px;
    min-width: 40px;
    min-height: 44px;
  }

  .study-sheet-close {
    margin-left: 3px;
    color: var(--reader-danger);
  }

  .study-sheet-backdrop:not([hidden]) {
    position: fixed;
    z-index: 70;
    inset: 0;
    display: block;
    width: 100%;
    height: 100%;
    padding: 0;
    border: 0;
    background: rgba(12, 28, 26, 0.48);
  }

  body.has-study-sheet {
    overflow: hidden;
  }

  body.has-study-sheet .mobile-panel-tabs {
    visibility: hidden;
    pointer-events: none;
  }

  .reader-app[data-mobile-layout="chess"] .chess-panel {
    overflow: visible;
  }

  .reader-app[data-mobile-layout="chess"] .chess-workspace {
    padding-bottom: max(6px, var(--reader-safe-bottom, env(safe-area-inset-bottom)));
  }

  .reader-app[data-mobile-layout="chess"] .board-column {
    width: min(100%, 680px, calc(100svh - var(--reader-header-height) - var(--reader-tab-height) - 166px));
    min-width: min(282px, calc(100vw - 16px));
  }
}

@media (max-height: 600px) and (pointer: coarse) and (orientation: landscape) {
  .board-coordinate-frame--editor {
    /* Deja visibles las letras inferiores incluso con la cabecera del modal. */
    width: min(100%, calc(100dvh - 56px));
  }

  .reader-app,
  .reader-app[data-mobile-layout="combined"] {
    grid-template-rows: var(--reader-safe-top, env(safe-area-inset-top)) 0 minmax(0, 1fr);
  }

  .reader-app > .app-header {
    display: none;
  }

  .mobile-panel-tabs {
    position: fixed;
    z-index: 55;
    bottom: max(6px, var(--reader-safe-bottom, env(safe-area-inset-bottom)));
    left: max(8px, var(--reader-safe-left, env(safe-area-inset-left)));
    width: min(276px, calc(100vw - var(--atril-board-size) - 36px - var(--reader-safe-left, env(safe-area-inset-left)) - var(--reader-safe-right, env(safe-area-inset-right))));
    min-width: 232px;
    border: 1px solid var(--reader-line-strong);
    border-radius: 10px;
    box-shadow: 0 8px 24px rgba(24, 48, 45, 0.2);
  }

  .reader-app[data-mobile-layout="combined"] .study-workspace {
    grid-template-columns: minmax(250px, 1fr) var(--atril-divider-size) calc(var(--atril-board-size) + var(--reader-coord-inline) + 8px);
    grid-template-rows: minmax(0, 1fr);
  }

  .reader-app[data-mobile-layout="combined"] .pdf-panel,
  .reader-app[data-mobile-layout="combined"] .workspace-divider,
  .reader-app[data-mobile-layout="combined"] .chess-panel {
    grid-row: 1;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-panel {
    grid-column: 1;
  }

  .reader-app[data-mobile-layout="combined"] .workspace-divider {
    grid-column: 2;
    cursor: col-resize;
  }

  .reader-app[data-mobile-layout="combined"] .workspace-divider::before {
    width: 44px;
    height: 52px;
  }

  .reader-app[data-mobile-layout="combined"] .workspace-divider__handle {
    width: 7px;
    height: 52px;
  }

  .reader-app[data-mobile-layout="combined"] .workspace-divider__handle i::before {
    content: "\f7a5";
  }

  .reader-app[data-mobile-layout="combined"] .chess-panel {
    grid-column: 3;
    width: auto;
    height: 100svh;
  }

  .reader-app[data-mobile-layout="combined"] .chess-workspace {
    padding-bottom: 2px;
  }

  .reader-app[data-mobile-layout="combined"] .chess-board {
    max-width: none;
  }

  .reader-app[data-mobile-layout="combined"] .board-coordinate-frame {
    max-width: calc(100svh - 52px);
  }

  .reader-app[data-mobile-layout="combined"] .mobile-study-tray {
    display: flex;
  }

  .reader-app[data-mobile-layout="combined"] .pdf-compact-menu .compact-menu__surface {
    top: 46px;
    right: max(4px, var(--reader-safe-right, env(safe-area-inset-right)));
    max-width: calc(100vw - var(--atril-board-size) - 28px - var(--reader-safe-left, env(safe-area-inset-left)) - var(--reader-safe-right, env(safe-area-inset-right)));
    max-height: calc(100dvh - 58px - var(--reader-safe-top, env(safe-area-inset-top)) - var(--reader-safe-bottom, env(safe-area-inset-bottom)));
  }

  .reader-app[data-mobile-layout="combined"] .chess-compact-menu .compact-menu__surface {
    right: max(8px, var(--reader-safe-right, env(safe-area-inset-right)));
  }

  .reader-app[data-mobile-layout="pdf"] .study-workspace,
  .reader-app[data-mobile-layout="chess"] .study-workspace {
    display: block;
    padding: 4px;
  }

  .reader-app[data-mobile-layout="chess"] .chess-panel {
    height: 100svh;
  }

  .reader-app[data-mobile-layout="chess"] .board-column {
    width: min(100%, calc(100svh - 158px));
  }

  .reader-app[data-mobile-layout="chess"] .mobile-study-tray {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

@media print {
  body {
    overflow: visible;
  }

  .app-header,
  .mobile-panel-tabs,
  .pdf-panel,
  .workspace-divider,
  .panel-heading-actions,
  .panel-toolbar,
  .app-footer,
  .panel-footnote {
    display: none !important;
  }

  .reader-app,
  .study-workspace,
  .study-panel {
    display: block;
    width: auto;
    height: auto;
    overflow: visible;
    border: 0;
    box-shadow: none;
  }
}