:root {
  --paper: #fbf7ed;
  --paper-deep: #f0e5d0;
  --ink: #1f241d;
  --muted: #6b6357;
  --line: rgba(69, 55, 34, 0.14);
  --panel: rgba(255, 252, 245, 0.88);
  --panel-solid: #fffaf0;
  --green: #1f6b4b;
  --green-deep: #174b36;
  --gold: #a96f1d;
  --shadow: 0 20px 60px rgba(61, 43, 20, 0.10);
  --classic-reading-content-width: 740px;
  --classic-reading-page-height: clamp(440px, calc(100dvh - 280px), 560px);
  --classic-reading-page-padding-top: clamp(30px, 3.4vw, 42px);
  --classic-reading-page-padding-bottom: clamp(18px, 2.4vw, 26px);
  --classic-reading-page-padding-x: clamp(28px, 4.4vw, 50px);
  --classic-reading-font-default: 24px;
  --classic-reading-line-default: 1.88;
  --classic-reading-font-compact: 22px;
  --classic-reading-line-compact: 1.8;
  --classic-reading-font-dense: 20px;
  --classic-reading-line-dense: 1.72;
  --classic-reading-font-weight: 400;
  --classic-reading-letter-spacing: 0.012em;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 16% 8%, rgba(169, 111, 29, 0.16), transparent 30%),
    radial-gradient(circle at 88% 10%, rgba(31, 107, 75, 0.16), transparent 28%),
    linear-gradient(135deg, #efe0c4 0%, #fbf7ed 42%, #f7efe1 100%);
  font-family: "Source Han Serif SC", "Noto Serif CJK SC", "Songti SC", "STSong", serif;
}

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

button {
  cursor: pointer;
}

.classics-shell {
  width: min(1600px, calc(100% - 20px));
  margin: 0 auto;
  padding: 14px 0 22px;
}

.classics-topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 12px 14px;
  margin-bottom: 14px;
  border: 1px solid var(--line);
  border-radius: 26px;
  background: rgba(255, 250, 240, 0.76);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.classics-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ink);
}

.classics-brand img {
  width: 42px;
  height: 42px;
  border-radius: 15px;
  object-fit: cover;
}

.classics-brand strong,
.classics-brand em {
  display: block;
}

.classics-brand strong {
  font-size: 17px;
  letter-spacing: 0.02em;
}

.classics-brand em {
  margin-top: 2px;
  color: var(--muted);
  font-style: normal;
  font-size: 12px;
}

.classics-nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.classics-nav a,
.soft-btn,
.primary-btn {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 9px 14px;
  text-decoration: none;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.52);
}

.primary-btn {
  width: 100%;
  margin-top: 10px;
  color: #fff;
  background: var(--green);
  border-color: var(--green);
  font-weight: 700;
}

.soft-btn:hover,
.classics-nav a:hover {
  border-color: rgba(31, 107, 75, 0.32);
  color: var(--green-deep);
}

.mobile-reader-topbar,
.mobile-inline-tools,
.mobile-drawer-head,
.mobile-drawer-backdrop {
  display: none;
}

.soft-btn:disabled,
.primary-btn:disabled {
  cursor: not-allowed;
  opacity: 0.46;
  color: rgba(31, 36, 29, 0.42);
  border-color: rgba(69, 55, 34, 0.10);
  background: rgba(255, 255, 255, 0.34);
}

.soft-btn:disabled:hover,
.primary-btn:disabled:hover {
  color: rgba(31, 36, 29, 0.42);
  border-color: rgba(69, 55, 34, 0.10);
}

.classics-grid {
  display: grid;
  grid-template-columns: 260px minmax(760px, 1fr) 280px;
  gap: 12px;
  align-items: start;
}

.library-panel,
.study-panel {
  display: grid;
  gap: 12px;
  position: sticky;
  top: 14px;
  align-content: start;
  max-height: calc(100vh - 28px);
  overflow: auto;
}

.panel-card,
.reader-card,
.reader-empty {
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

.panel-card {
  padding: 16px;
}

.library-panel .panel-card,
.study-panel .panel-card {
  border-radius: 22px;
  padding: 12px;
}

.panel-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.panel-heading.compact {
  margin-bottom: 10px;
}

.library-panel .panel-heading,
.study-panel .panel-heading {
  gap: 8px;
  margin-bottom: 10px;
}

.eyebrow {
  margin: 0 0 3px;
  color: var(--gold);
  font: 700 11px/1.2 "IBM Plex Sans", "Noto Sans SC", sans-serif;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2 {
  margin-bottom: 0;
  line-height: 1.18;
  letter-spacing: -0.02em;
}

h1 {
  font-size: 25px;
}

h2 {
  font-size: 20px;
}

h3 {
  font-size: 16px;
  color: var(--green-deep);
}

.library-panel h1 {
  font-size: 22px;
}

.library-panel h2,
.study-panel h2 {
  font-size: 18px;
}

.library-panel .soft-btn {
  padding: 7px 10px;
  font-size: 12px;
}

.study-panel .primary-btn {
  padding: 8px 11px;
  font-size: 13px;
}

.library-search input,
.filter-stack select,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.68);
  color: var(--ink);
}

.library-search input {
  padding: 9px 11px;
}

.filter-stack {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  margin: 8px 0;
}

.filter-stack span {
  display: block;
  margin: 0 0 5px;
  color: var(--muted);
  font-size: 12px;
}

.filter-stack select {
  padding: 8px 9px;
}

.book-list,
.toc-tree,
.mark-list,
.history-list {
  display: grid;
  gap: 7px;
}

.library-card .book-list {
  max-height: clamp(220px, calc(100vh - 270px), 520px);
  overflow-x: hidden;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-y: auto;
  padding-right: 6px;
  padding-bottom: 14px;
  scrollbar-width: thin;
  scrollbar-color: rgba(91, 143, 105, 0.55) transparent;
  scrollbar-gutter: stable;
}

.library-card .book-list::-webkit-scrollbar {
  width: 4px;
}

.library-card .book-list::-webkit-scrollbar-track {
  background: transparent;
}

.library-card .book-list::-webkit-scrollbar-thumb {
  border-radius: 999px;
  background: rgba(32, 128, 92, 0.35);
}

.library-card .book-list::-webkit-scrollbar-thumb:hover {
  background: rgba(32, 128, 92, 0.52);
}

.book-card,
.toc-node,
.mark-item,
.history-item,
.search-result {
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 10px 11px;
  background: rgba(255, 255, 255, 0.52);
}

.book-card {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 8px;
  padding: 8px 9px;
  border-radius: 15px;
  text-align: left;
}

.book-card > span:last-child {
  min-width: 0;
}

.book-card.is-active,
.toc-node.is-active {
  border-color: rgba(31, 107, 75, 0.45);
  background: rgba(235, 247, 238, 0.72);
}

.book-cover {
  display: grid;
  place-items: center;
  width: 34px;
  height: 44px;
  border-radius: 12px;
  color: #fff;
  background: linear-gradient(150deg, var(--green-deep), var(--gold));
  font-size: 12px;
  font-weight: 800;
}

.book-title {
  display: -webkit-box;
  overflow: hidden;
  font-weight: 800;
  font-size: 13px;
  line-height: 1.35;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.book-meta,
.book-desc,
.toc-meta,
.mark-meta,
.history-meta {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}

.book-card .book-meta,
.book-card .book-desc {
  display: -webkit-box;
  overflow: hidden;
  -webkit-box-orient: vertical;
}

.book-card .book-meta {
  font-size: 11px;
  line-height: 1.35;
  -webkit-line-clamp: 1;
}

.book-card .book-desc {
  margin-top: 2px;
  font-size: 11px;
  line-height: 1.45;
  -webkit-line-clamp: 2;
}

.toc-node {
  width: 100%;
  border-radius: 15px;
  padding: 8px 10px;
  text-align: left;
}

.toc-node strong {
  font-size: 13px;
  line-height: 1.35;
}

.toc-depth-1 {
  margin-left: 8px;
}

.toc-depth-2,
.toc-depth-3 {
  margin-left: 16px;
}

.reader-panel {
  min-height: calc(100vh - 110px);
  min-width: 0;
}

.reader-empty {
  min-height: calc(100vh - 110px);
  display: grid;
  place-content: center;
  padding: 40px;
  text-align: center;
}

.reader-empty h2 {
  font-size: clamp(30px, 5vw, 56px);
}

.reader-empty p {
  max-width: 620px;
  color: var(--muted);
  line-height: 1.8;
}

.reader-card {
  padding: clamp(34px, 4.2vw, 62px) clamp(28px, 4.6vw, 72px);
}

.reader-card > .reader-meta,
.reader-card > .reader-progress,
.reader-card > .reading-block,
.reader-card > .reader-page-nav,
.reader-card > .reader-actions,
.reader-card > .reader-support,
.reader-card > .reader-pagination {
  width: min(100%, var(--classic-reading-content-width));
  margin-left: auto;
  margin-right: auto;
}

.reader-pagination {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: flex-start;
  flex-wrap: wrap;
}

.reader-meta {
  display: grid;
  justify-content: start;
  gap: 4px;
  margin-bottom: 18px;
  color: rgba(107, 99, 87, 0.82);
}

#reader-book-meta {
  display: block;
  max-width: min(100%, 680px);
  overflow: hidden;
  color: rgba(107, 99, 87, 0.76);
  font: 500 16px/1.6 "IBM Plex Sans", "Noto Sans SC", sans-serif;
  text-overflow: ellipsis;
  white-space: nowrap;
}

#reader-path {
  display: -webkit-box;
  max-width: min(100%, 720px);
  overflow: hidden;
  color: rgba(107, 99, 87, 0.56);
  font: 500 15px/1.55 "IBM Plex Sans", "Noto Sans SC", sans-serif;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow-wrap: anywhere;
}

.reader-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-start;
  margin-top: -8px;
  margin-bottom: 18px;
}

.reader-actions .soft-btn {
  min-height: 48px;
  padding: 0 18px;
  color: rgba(31, 36, 29, 0.78);
  background: rgba(255, 255, 255, 0.38);
  font: 600 18px/1.2 "IBM Plex Sans", "Noto Sans SC", sans-serif;
}

.reader-actions .memorize-action {
  color: var(--green-deep);
  border-color: rgba(31, 107, 75, 0.22);
  background: rgba(235, 247, 238, 0.58);
}

.reader-actions .memorize-action:disabled {
  cursor: not-allowed;
  opacity: 0.42;
}

.reading-block {
  margin-top: 16px;
  margin-bottom: 22px;
}

.classic-text {
  font-size: clamp(17px, 1.4vw, 21px);
  line-height: 1.8;
  white-space: pre-wrap;
}

.reader-progress {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px 12px;
  align-items: center;
  color: var(--muted);
  font: 600 16px/1.45 "IBM Plex Sans", "Noto Sans SC", sans-serif;
}

.reader-progress-track {
  grid-column: 1 / -1;
  position: relative;
  height: 24px;
  overflow: visible;
  border-radius: 999px;
  background: transparent;
  cursor: pointer;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

.reader-progress-track::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 5px;
  border-radius: 999px;
  background: rgba(69, 55, 34, 0.10);
  transform: translateY(-50%);
}

.reader-progress-fill {
  position: absolute;
  top: 50%;
  left: 0;
  width: 0%;
  height: 5px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--green), var(--gold));
  transform: translateY(-50%);
  transition: width 180ms ease;
}

.reader-progress-thumb {
  position: absolute;
  top: 50%;
  left: 0%;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255, 253, 247, 0.96);
  border-radius: 999px;
  background: var(--green);
  box-shadow: 0 5px 14px rgba(31, 107, 75, 0.26);
  transform: translate(-50%, -50%);
  transition: left 180ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.reader-progress-tooltip {
  position: absolute;
  top: -34px;
  left: 0%;
  z-index: 4;
  max-width: min(320px, 82vw);
  padding: 6px 10px;
  border: 1px solid rgba(31, 107, 75, 0.18);
  border-radius: 999px;
  background: rgba(255, 253, 247, 0.98);
  box-shadow: 0 10px 26px rgba(61, 43, 20, 0.14);
  color: var(--ink);
  font: 600 13px/1.35 "IBM Plex Sans", "Noto Sans SC", sans-serif;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  pointer-events: none;
  transform: translateX(-50%);
}

.reader-progress-track:hover .reader-progress-thumb,
.reader-progress-track:focus-visible .reader-progress-thumb,
.reader-progress-track.is-dragging .reader-progress-thumb {
  transform: translate(-50%, -50%) scale(1.12);
  box-shadow: 0 7px 18px rgba(31, 107, 75, 0.34);
}

.reader-progress-track.is-dragging .reader-progress-fill,
.reader-progress-track.is-dragging .reader-progress-thumb {
  transition: none;
}

.reader-progress-track.is-disabled {
  cursor: default;
  opacity: 0.54;
}

.reader-progress-track.is-disabled .reader-progress-thumb {
  background: rgba(69, 55, 34, 0.28);
  box-shadow: none;
}

.page-reading {
  display: flex;
  flex-direction: column;
  height: var(--classic-reading-page-height);
  overflow: hidden;
  padding: var(--classic-reading-page-padding-top) var(--classic-reading-page-padding-x) var(--classic-reading-page-padding-bottom);
  border: 1px solid rgba(69, 55, 34, 0.12);
  border-radius: 26px;
  background:
    linear-gradient(90deg, rgba(169, 111, 29, 0.06), transparent 18%, transparent 82%, rgba(31, 107, 75, 0.05)),
    rgba(255, 253, 247, 0.78);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.62), 0 16px 42px rgba(61, 43, 20, 0.08);
}

.page-reading h3 {
  flex: 0 0 auto;
  margin-bottom: 20px;
  color: var(--gold);
  font: 700 18px/1.4 "IBM Plex Sans", "Noto Sans SC", sans-serif;
  letter-spacing: 0.03em;
}

.main-reading-text {
  flex: 1 1 auto;
  min-height: 0;
  overflow: hidden;
  margin-bottom: 0;
  font-weight: var(--classic-reading-font-weight);
  letter-spacing: var(--classic-reading-letter-spacing);
}

.main-reading-text.reading-size-default {
  font-size: var(--classic-reading-font-default);
  line-height: var(--classic-reading-line-default);
}

.main-reading-text.reading-size-compact {
  font-size: var(--classic-reading-font-compact);
  line-height: var(--classic-reading-line-compact);
}

.main-reading-text.reading-size-dense {
  font-size: var(--classic-reading-font-dense);
  line-height: var(--classic-reading-line-dense);
}

.plain,
.mechanism {
  color: #3f493e;
  font-size: 17px;
  line-height: 1.85;
}

.keyword-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 10px;
}

.keyword-row span {
  border-radius: 999px;
  padding: 6px 10px;
  color: var(--green-deep);
  background: rgba(31, 107, 75, 0.10);
  font-size: 12px;
  font-weight: 700;
}

.reader-page-nav {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  flex: 0 0 auto;
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid rgba(69, 55, 34, 0.10);
}

.reader-page-nav .soft-btn {
  min-width: 120px;
  min-height: 42px;
  padding: 8px 16px;
  font-weight: 800;
}

.reader-support {
  display: grid;
  gap: 8px;
  margin-top: 12px;
}

.reader-detail-panel {
  border: 1px solid rgba(69, 55, 34, 0.12);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.42);
}

.reader-detail-panel summary {
  cursor: pointer;
  padding: 10px 12px;
  color: var(--green-deep);
  font: 800 13px/1.35 "IBM Plex Sans", "Noto Sans SC", sans-serif;
}

.reader-detail-panel .classic-text,
.reader-detail-panel .keyword-row {
  margin: 0;
  padding: 0 12px 12px;
}

.reader-pagination {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

textarea {
  min-height: 96px;
  padding: 10px;
  resize: vertical;
  line-height: 1.65;
}

.mark-list {
  margin-top: 10px;
}

.mark-item {
  display: grid;
  gap: 4px;
  padding: 8px 9px;
  border-radius: 14px;
}

.mark-kind {
  color: var(--green-deep);
  font-weight: 800;
  font-size: 13px;
}

.mark-text {
  line-height: 1.55;
  font-size: 13px;
}

.mark-delete {
  justify-self: start;
  border: 0;
  background: transparent;
  color: #9b442a;
  padding: 0;
}

.ai-action-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
}

.ai-action-grid button {
  border: 1px solid rgba(31, 107, 75, 0.18);
  border-radius: 13px;
  padding: 8px 10px;
  color: var(--green-deep);
  background: rgba(235, 247, 238, 0.62);
  text-align: left;
  font-size: 13px;
  font-weight: 760;
}

.ai-answer {
  margin-top: 10px;
  border: 1px dashed rgba(31, 107, 75, 0.22);
  border-radius: 16px;
  padding: 10px;
  min-height: 90px;
  color: #3f493e;
  font-size: 13px;
  line-height: 1.65;
  white-space: pre-wrap;
  background: rgba(255, 255, 255, 0.42);
}

.history-item {
  padding: 8px 9px;
  border-radius: 14px;
}

.history-item strong {
  font-size: 13px;
  line-height: 1.35;
}

.status {
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 1360px) {
  .classics-grid {
    grid-template-columns: 250px minmax(620px, 1fr) 260px;
    gap: 10px;
  }

  .study-panel {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 1180px) {
  .classics-grid {
    grid-template-columns: 230px minmax(520px, 1fr) 240px;
  }

  .library-panel .panel-card,
  .study-panel .panel-card {
    padding: 10px;
  }
}

@media (max-width: 980px) {
  :root {
    --classic-reading-content-width: 100%;
    --classic-reading-page-height: clamp(360px, calc(100dvh - 250px), 500px);
    --classic-reading-page-padding-top: 20px;
    --classic-reading-page-padding-bottom: 14px;
    --classic-reading-page-padding-x: 16px;
    --classic-reading-font-default: 19px;
    --classic-reading-line-default: 1.78;
    --classic-reading-font-compact: 18px;
    --classic-reading-line-compact: 1.72;
    --classic-reading-font-dense: 17px;
    --classic-reading-line-dense: 1.66;
  }

  body.mobile-drawer-open {
    overflow: hidden;
  }

  .classics-shell {
    width: 100%;
    padding: 8px 16px calc(18px + env(safe-area-inset-bottom));
  }

  .classics-topbar {
    display: none;
  }

  .mobile-reader-topbar {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto auto;
    align-items: center;
    gap: 8px;
    width: 100%;
    max-width: 640px;
    margin: 0 auto 12px;
    padding: 9px 10px;
    border: 1px solid rgba(69, 55, 34, 0.12);
    border-radius: 20px;
    background: rgba(255, 250, 240, 0.90);
    box-shadow: 0 14px 36px rgba(61, 43, 20, 0.09);
    backdrop-filter: blur(16px);
    position: sticky;
    top: 6px;
    z-index: 40;
  }

  .mobile-reader-back,
  .mobile-reader-tool,
  .mobile-drawer-close {
    border: 1px solid rgba(31, 107, 75, 0.16);
    border-radius: 999px;
    color: var(--green-deep);
    background: rgba(255, 255, 255, 0.66);
    text-decoration: none;
    font: 800 12px/1.1 "IBM Plex Sans", "Noto Sans SC", sans-serif;
  }

  .mobile-reader-back,
  .mobile-reader-tool {
    min-height: 34px;
    padding: 0 10px;
    display: inline-grid;
    place-items: center;
    white-space: nowrap;
  }

  .mobile-reader-heading {
    min-width: 0;
    display: grid;
    gap: 2px;
  }

  .mobile-reader-heading strong,
  .mobile-reader-heading span {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .mobile-reader-heading strong {
    color: var(--ink);
    font-size: 15px;
    line-height: 1.25;
  }

  .mobile-reader-heading span {
    color: rgba(107, 99, 87, 0.68);
    font: 600 12px/1.35 "IBM Plex Sans", "Noto Sans SC", sans-serif;
  }

  .classics-grid {
    display: block;
  }

  .reader-panel {
    min-height: auto;
    max-width: 640px;
    margin: 0 auto;
  }

  .reader-empty {
    min-height: 240px;
    padding: 28px 18px;
  }

  .reader-empty h2 {
    font-size: 28px;
  }

  .reader-card {
    padding: 16px 12px;
    border-radius: 24px;
  }

  .reader-card > .reader-meta,
  .reader-card > .reader-progress,
  .reader-card > .reading-block,
  .reader-card > .mobile-inline-tools,
  .reader-card > .reader-actions,
  .reader-card > .reader-support,
  .reader-card > .reader-pagination {
    width: 100%;
  }

  .library-panel,
  .study-panel {
    position: fixed;
    z-index: 90;
    max-height: none;
    overflow-x: hidden;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: thin;
    scrollbar-color: rgba(91, 143, 105, 0.55) transparent;
    opacity: 0;
    pointer-events: none;
    visibility: hidden;
  }

  .library-panel {
    top: 0;
    bottom: 0;
    left: 0;
    width: min(88vw, 380px);
    height: 100dvh;
    padding: 12px;
    background:
      radial-gradient(circle at 0% 0%, rgba(169, 111, 29, 0.12), transparent 34%),
      rgba(255, 250, 240, 0.96);
    box-shadow: 24px 0 60px rgba(31, 36, 29, 0.20);
    transform: translateX(-105%);
    transition: transform 190ms ease;
  }

  body.mobile-library-open .library-panel {
    opacity: 1;
    pointer-events: auto;
    transform: translateX(0);
    visibility: visible;
  }

  .study-panel {
    left: 12px;
    right: 12px;
    bottom: 12px;
    max-height: min(78dvh, 680px);
    display: grid;
    gap: 10px;
    padding: 10px;
    border: 1px solid rgba(69, 55, 34, 0.14);
    border-radius: 26px;
    background: rgba(255, 250, 240, 0.97);
    box-shadow: 0 -22px 62px rgba(31, 36, 29, 0.20);
    transform: translateY(calc(100% + 36px));
    transition: transform 190ms ease;
  }

  body.mobile-tools-open .study-panel {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
    visibility: visible;
  }

  .mobile-drawer-backdrop:not([hidden]) {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 80;
    background: rgba(31, 36, 29, 0.30);
    backdrop-filter: blur(5px);
  }

  .mobile-drawer-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    position: sticky;
    top: 0;
    z-index: 2;
    margin: -2px -2px 10px;
    padding: 8px 4px 10px;
    background: linear-gradient(180deg, rgba(255, 250, 240, 0.98), rgba(255, 250, 240, 0.86));
    backdrop-filter: blur(12px);
  }

  .mobile-drawer-head strong {
    color: var(--green-deep);
    font-size: 16px;
  }

  .mobile-drawer-close {
    min-height: 32px;
    padding: 0 11px;
  }

  .library-panel::-webkit-scrollbar,
  .study-panel::-webkit-scrollbar {
    width: 4px;
  }

  .library-panel::-webkit-scrollbar-track,
  .study-panel::-webkit-scrollbar-track {
    background: transparent;
  }

  .library-panel::-webkit-scrollbar-thumb,
  .study-panel::-webkit-scrollbar-thumb {
    border-radius: 999px;
    background: rgba(32, 128, 92, 0.35);
  }

  .library-card {
    overflow: visible;
  }

  .library-card .book-list {
    max-height: 36vh;
    max-height: 36dvh;
    margin-top: 2px;
    padding-right: 6px;
    padding-bottom: 14px;
  }

  .toc-tree {
    max-height: 34vh;
    max-height: 34dvh;
    overflow-x: hidden;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    padding-right: 6px;
    scrollbar-width: thin;
    scrollbar-color: rgba(91, 143, 105, 0.45) transparent;
  }

  .toc-tree::-webkit-scrollbar {
    width: 4px;
  }

  .toc-tree::-webkit-scrollbar-track {
    background: transparent;
  }

  .toc-tree::-webkit-scrollbar-thumb {
    border-radius: 999px;
    background: rgba(32, 128, 92, 0.30);
  }

  .filter-stack {
    grid-template-columns: 1fr;
  }

  #reader-book-meta,
  #reader-path {
    max-width: 100%;
    font-size: 13px;
  }

  .reader-meta {
    margin-bottom: 10px;
  }

  .reader-progress {
    grid-template-columns: 1fr;
    gap: 5px;
    font-size: 13px;
  }

  .reading-block {
    margin-top: 10px;
    margin-bottom: 12px;
  }

  .page-reading {
    border-radius: 22px;
  }

  .page-reading h3 {
    margin-bottom: 12px;
    font-size: 14px;
  }

  .reader-page-nav {
    gap: 8px;
    margin-top: 12px;
    padding-top: 10px;
  }

  .reader-page-nav .soft-btn {
    flex: 1 1 0;
    min-width: 0;
    min-height: 38px;
    padding: 8px 10px;
    font-size: 13px;
  }

  .mobile-inline-tools {
    display: grid;
    gap: 10px;
    margin: 0 auto 12px;
  }

  .mobile-ai-strip {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding: 2px 2px 8px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .mobile-ai-strip::-webkit-scrollbar {
    display: none;
  }

  .mobile-ai-strip button {
    flex: 0 0 auto;
    min-height: 36px;
    border: 1px solid rgba(31, 107, 75, 0.18);
    border-radius: 999px;
    padding: 0 12px;
    color: var(--green-deep);
    background: rgba(235, 247, 238, 0.70);
    font: 800 13px/1 "IBM Plex Sans", "Noto Sans SC", sans-serif;
  }

  .mobile-note-panel {
    display: grid;
    gap: 8px;
    padding: 10px;
    border: 1px solid rgba(31, 107, 75, 0.14);
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.50);
  }

  .mobile-note-panel[hidden] {
    display: none;
  }

  .mobile-note-panel textarea {
    min-height: 76px;
  }

  .mobile-note-panel .primary-btn {
    min-height: 38px;
    margin-top: 0;
    font-size: 13px;
  }

  .mobile-ai-answer {
    min-height: 54px;
    padding: 10px 11px;
    border: 1px dashed rgba(31, 107, 75, 0.22);
    border-radius: 18px;
    color: #3f493e;
    background: rgba(255, 255, 255, 0.46);
    font: 500 13px/1.65 "IBM Plex Sans", "Noto Sans SC", sans-serif;
    white-space: pre-wrap;
  }

  .reader-actions {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 7px;
    margin-top: 0;
    margin-bottom: 12px;
  }

  .reader-actions .soft-btn {
    min-height: 38px;
    padding: 0 10px;
    font-size: 13px;
  }

  .reader-support {
    display: none;
  }

  .reader-pagination {
    margin-top: 14px;
    padding-top: 12px;
  }

  .reader-pagination .soft-btn {
    flex: 1 1 0;
    min-width: 0;
  }

  .study-panel .panel-card {
    box-shadow: none;
  }

  .ai-action-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .ai-action-grid button {
    font-size: 12px;
    padding: 8px;
  }

  textarea {
    min-height: 74px;
  }
}

@supports not (height: 100dvh) {
  @media (max-width: 980px) {
    .library-panel {
      height: 100vh;
    }

    .page-reading {
      height: clamp(360px, calc(100vh - 250px), 500px);
    }
  }
}

@media (max-width: 560px) {
  .classics-brand em {
    display: none;
  }

  .classics-nav a {
    font-size: 11px;
    padding: 7px 4px;
  }

  .panel-card {
    padding: 12px;
    border-radius: 20px;
  }

  .library-panel .panel-card,
  .study-panel .panel-card {
    padding: 10px;
  }

  .library-card .book-list {
    max-height: 34vh;
    max-height: 34dvh;
  }

  .toc-tree {
    max-height: 32vh;
    max-height: 32dvh;
  }

  .book-card {
    grid-template-columns: 30px 1fr;
    padding: 7px 8px;
  }

  .book-cover {
    width: 30px;
    height: 40px;
  }

  .reader-card {
    padding: 14px 10px;
  }

  .reader-empty {
    min-height: 220px;
  }

  .reader-empty h2 {
    font-size: 24px;
  }

  .page-reading {
    height: clamp(340px, calc(100vh - 235px), 460px);
    height: clamp(340px, calc(100dvh - 235px), 460px);
  }

  .main-reading-text.reading-size-default {
    font-size: 18px;
    line-height: 1.74;
  }

  .main-reading-text.reading-size-compact {
    font-size: 17px;
    line-height: 1.68;
  }

  .main-reading-text.reading-size-dense {
    font-size: 16px;
    line-height: 1.62;
  }
}