:root {
  --bg: #f8ecff;
  --bg-soft: rgba(248, 236, 255, 0.82);
  --paper: #ffffff;
  --paper-strong: #f8ecff;
  --ink: #080f2b;
  --muted: #4a5068;
  --line: rgba(8, 15, 43, 0.10);
  --line-strong: rgba(8, 15, 43, 0.18);
  --brand: #6e66f0;
  --brand-strong: #5248d4;
  --brand-soft: #f3e0ff;
  --accent: #6e66f0;
  --accent-soft: rgba(110, 102, 240, 0.10);
  --success: #2b6a4b;
  --warning: #9a5a1a;
  --shadow-soft: 0 20px 50px rgba(110, 102, 240, 0.08);
  --shadow-card: 0 24px 60px rgba(110, 102, 240, 0.10);
  --shadow-float: 0 12px 30px rgba(110, 102, 240, 0.08);
  --font-ui: "Segoe UI", "Trebuchet MS", "Helvetica Neue", Arial, sans-serif;
  --font-reading: Georgia, "Times New Roman", serif;
  --font-mono: "Consolas", "Courier New", monospace;
  --sidebar-width: 320px;
  --header-height: 64px;
  --content-width: 980px;
  --reader-gap: 24px;
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 10px;
}

body[data-theme="dark"] {
  --bg: #0a0e1a;
  --bg-soft: rgba(14, 18, 32, 0.88);
  --paper: #111627;
  --paper-strong: #161c33;
  --ink: #e8e0f8;
  --muted: #9a94b0;
  --line: rgba(232, 224, 248, 0.10);
  --line-strong: rgba(232, 224, 248, 0.18);
  --brand: #9d96f0;
  --brand-strong: #b8b2ff;
  --brand-soft: rgba(157, 150, 240, 0.08);
  --accent: #9d96f0;
  --accent-soft: rgba(157, 150, 240, 0.12);
  --success: #72bf96;
  --warning: #e0a15f;
  --shadow-soft: 0 18px 45px rgba(0, 0, 0, 0.34);
  --shadow-card: 0 24px 60px rgba(0, 0, 0, 0.42);
  --shadow-float: 0 12px 30px rgba(0, 0, 0, 0.35);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--font-ui);
  background:
    radial-gradient(circle at top left, rgba(110, 102, 240, 0.10), transparent 28%),
    radial-gradient(circle at top right, rgba(243, 224, 255, 0.20), transparent 24%),
    linear-gradient(180deg, var(--bg), color-mix(in srgb, var(--bg) 86%, #ffffff 14%));
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

img {
  display: block;
  max-width: 100%;
}

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--brand));
  z-index: 1200;
  transition: width 0.12s ease-out;
  pointer-events: none;
}

.header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--header-height);
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 0 20px;
  background: color-mix(in srgb, var(--paper) 76%, transparent);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
  z-index: 1100;
}

.header__logo,
.logo {
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--brand-strong);
  letter-spacing: 0.02em;
}

.header__logo span {
  color: var(--accent);
}

.logo {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  text-decoration: none;
}

.logo img {
  display: block;
  height: 32px;
  width: auto;
}

.header__spacer {
  flex: 1;
}

.header__lang,
.header__locale,
.header__burger,
.view-toggle__btn,
.reader-toolbar__button,
.reader-search__button,
.prompt-block__copy,
.template-card__copy {
  appearance: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  color: var(--brand-strong);
  font: inherit;
  cursor: pointer;
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}

.header__lang:hover,
.header__locale:hover,
.header__burger:hover,
.view-toggle__btn:hover,
.reader-toolbar__button:hover,
.reader-search__button:hover,
.prompt-block__copy:hover,
.template-card__copy:hover {
  transform: translateY(-1px);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-float);
}

.header__lang,
.header__locale,
.reader-toolbar__button,
.reader-search__button {
  padding: 9px 14px;
  font-size: 0.88rem;
  font-weight: 600;
}

.header__locale {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 48px;
  flex-shrink: 0;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.header__burger {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  font-size: 1.4rem;
  align-items: center;
  justify-content: center;
}

.sidebar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  overflow-y: auto;
  padding: 18px 16px 22px;
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  border-right: 1px solid var(--line);
  box-shadow: inset -1px 0 0 rgba(255, 255, 255, 0.25);
  z-index: 1000;
}

.sidebar::-webkit-scrollbar {
  width: 8px;
}

.sidebar::-webkit-scrollbar-thumb {
  background: rgba(0, 0, 0, 0.14);
  border-radius: 999px;
}

.sidebar-search {
  position: sticky;
  top: 0;
  z-index: 2;
  margin-bottom: 18px;
  padding-bottom: 12px;
  background: linear-gradient(180deg, color-mix(in srgb, var(--paper) 95%, transparent), color-mix(in srgb, var(--paper) 82%, transparent));
}

.sidebar-search__input,
.reader-search__input,
.toc-search__input {
  width: 100%;
  padding: 12px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  color: var(--ink);
  font: inherit;
  outline: none;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.45);
}

.sidebar-search__input:focus,
.reader-search__input:focus,
.toc-search__input:focus {
  border-color: color-mix(in srgb, var(--accent) 68%, var(--line));
  box-shadow: 0 0 0 4px var(--accent-soft);
}

.sidebar__summary {
  margin-top: 10px;
  font-size: 0.76rem;
  color: var(--muted);
}

.sidebar__section {
  margin-bottom: 10px;
}

.sidebar__section.is-empty {
  display: none;
}

.sidebar__toggle {
  display: flex;
  align-items: center;
  width: 100%;
  padding: 10px 12px;
  border: 0;
  border-radius: 14px;
  background: transparent;
  color: var(--brand);
  font-size: 0.83rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  cursor: pointer;
}

.sidebar__toggle:hover {
  background: var(--accent-soft);
}

.sidebar__toggle::before {
  content: "▸";
  margin-right: 8px;
  font-size: 0.7rem;
  transform-origin: center;
  transition: transform 0.18s ease;
}

.sidebar__toggle.open::before {
  transform: rotate(90deg);
}

.sidebar__links {
  display: none;
  padding: 6px 0 0;
}

.sidebar__links.open {
  display: block;
}

.sidebar__link {
  display: block;
  margin-bottom: 4px;
  padding: 10px 12px 10px 15px;
  border-radius: 14px;
  border: 1px solid transparent;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  line-height: 1.35;
}

.sidebar__link:hover {
  background: color-mix(in srgb, var(--paper-strong) 84%, transparent);
  color: var(--brand-strong);
  border-color: var(--line);
}

.sidebar__link.active {
  background: linear-gradient(180deg, color-mix(in srgb, var(--brand-soft) 78%, transparent), color-mix(in srgb, var(--paper) 92%, transparent));
  border-color: color-mix(in srgb, var(--accent) 38%, var(--line));
  color: var(--brand-strong);
  box-shadow: var(--shadow-soft);
}

.sidebar__link.is-hidden,
.toc__item.is-hidden {
  display: none !important;
}

.sidebar__link .toc__num,
.toc__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2rem;
  padding-right: 0.2rem;
  color: var(--brand);
  font-weight: 700;
}

.main,
.content {
  position: relative;
  margin-top: var(--header-height);
  margin-left: var(--sidebar-width);
  padding: 36px clamp(18px, 3vw, 34px) 72px;
}

body.page--index .main,
body.page--index .content {
  margin-left: 0;
}

.main > *,
.content > * {
  width: min(100%, var(--content-width));
  max-width: var(--content-width);
  margin-left: auto;
  margin-right: auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(220px, 300px) minmax(0, 1fr);
  align-items: center;
  gap: 32px;
  margin-bottom: 26px;
  padding: clamp(24px, 4vw, 42px);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, color-mix(in srgb, var(--paper) 94%, transparent), color-mix(in srgb, var(--brand-soft) 62%, transparent));
  box-shadow: var(--shadow-card);
}

.hero__cover {
  width: 100%;
  max-width: 280px;
  justify-self: center;
  border-radius: 18px;
  border: 1px solid var(--line);
  box-shadow: 0 28px 48px rgba(28, 20, 16, 0.18);
}

.hero h1 {
  margin: 0 0 10px;
  font-family: var(--font-reading);
  font-size: clamp(2rem, 4vw, 3.3rem);
  line-height: 1.05;
  color: var(--brand-strong);
}

.hero__subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.library-panel {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 26px;
}

.hero,
.library-panel,
.book-visuals,
.toc-search,
.toc,
.page-header,
.reader-panels {
  width: 100%;
}

.library-card {
  padding: 18px 18px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  box-shadow: var(--shadow-soft);
}

.library-card__eyebrow {
  display: block;
  margin-bottom: 8px;
  font-size: 0.73rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.library-card__value {
  display: block;
  margin-bottom: 8px;
  color: var(--brand-strong);
  font-family: var(--font-reading);
  font-size: 1.75rem;
  line-height: 1;
}

.library-card p,
.continue-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.continue-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: flex-start;
}

.continue-card__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: 999px;
  background: linear-gradient(180deg, var(--brand), var(--brand-strong));
  color: #fff;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 700;
  box-shadow: var(--shadow-float);
}

.continue-card__link:hover {
  transform: translateY(-1px);
}

.toc-search {
  margin-bottom: 16px;
}

.toc {
  padding: clamp(22px, 3vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: color-mix(in srgb, var(--paper) 96%, transparent);
  box-shadow: var(--shadow-card);
}

.toc__group {
  margin-bottom: 22px;
}

.toc__group:last-child {
  margin-bottom: 0;
}

.toc__group-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 10px;
  margin-bottom: 12px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.toc__group-badge {
  padding: 4px 8px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--brand);
  font-size: 0.7rem;
}

.toc__item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 11px 0;
  border-bottom: 1px dashed var(--line);
  text-decoration: none;
}

.toc__item:last-child {
  border-bottom: 0;
}

.toc__item:hover {
  color: var(--brand-strong);
}

.toc__title {
  min-width: 0;
}

.toc__pages {
  color: var(--muted);
  font-size: 0.84rem;
  white-space: nowrap;
}

.breadcrumbs {
  margin-bottom: 18px;
  color: var(--muted);
  font-size: 0.85rem;
}

.breadcrumbs a {
  color: var(--brand);
  text-decoration: none;
}

.breadcrumbs a:hover {
  text-decoration: underline;
}

.breadcrumbs__sep {
  margin: 0 7px;
}

.page-header {
  margin-bottom: 22px;
  padding: clamp(22px, 3vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: color-mix(in srgb, var(--paper) 98%, transparent);
  box-shadow: var(--shadow-card);
}

.page-header h1 {
  margin: 0 0 12px;
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: clamp(2rem, 3.2vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.04;
}

.page-header__meta {
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.reader-toolbar {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) auto;
  gap: 16px;
  align-items: center;
  margin-top: 18px;
}

.reader-toolbar__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.reader-toolbar__chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  color: var(--muted);
  font-size: 0.82rem;
}

.reader-toolbar__search {
  display: flex;
  gap: 10px;
}

.reader-status {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.82rem;
  min-height: 1.2em;
}

.view-toggle {
  display: none;
}

.reader-panels {
  display: block;
}

.reader-panels .page-viewer {
  display: none;
}

.chapter-text,
.page-viewer {
  padding: clamp(22px, 3vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: color-mix(in srgb, var(--paper) 96%, transparent);
  box-shadow: var(--shadow-card);
}

.chapter-text {
  font-family: var(--font-ui);
  font-size: 1.03rem;
  line-height: 1.68;
  letter-spacing: -0.003em;
  text-wrap: pretty;
}

.chapter-text h2,
.chapter-text h3 {
  margin: 0 0 16px;
  color: var(--ink);
  font-family: var(--font-ui);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.12;
}

.chapter-text h2 {
  margin-top: 42px;
  padding-bottom: 0;
  border-bottom: 0;
  font-size: clamp(1.95rem, 1.65rem + 0.9vw, 2.45rem);
}

.chapter-text h2:first-child {
  margin-top: 0;
}

.chapter-text h3 {
  margin-top: 32px;
  font-size: clamp(1.34rem, 1.2rem + 0.45vw, 1.72rem);
}

.chapter-text p,
.chapter-text .num-item,
.chapter-text .bullet-item {
  margin: 0 0 18px;
  color: var(--ink);
}

.chapter-text p {
  font-family: var(--font-ui);
  font-size: 1.03rem;
  line-height: 1.68;
}

.chapter-text p + p {
  margin-top: -4px;
}

.chapter-text .num-item,
.chapter-text .bullet-item {
  position: relative;
  font-family: var(--font-ui);
  font-size: 1.02rem;
  line-height: 1.62;
}

.chapter-text .num-item {
  padding-left: 2rem;
}

.chapter-text .num-item strong {
  position: absolute;
  left: 0;
  top: 0;
  width: 1.5rem;
  color: var(--ink);
  font-weight: 800;
}

.chapter-text .bullet-item {
  padding-left: 1.35rem;
}

.chapter-text .bullet-item::before {
  content: "•";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--ink);
  font-weight: 800;
}

.chapter-text img {
  margin: 24px auto;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
}

.chapter-text .table-wrap + h2,
.chapter-text .table-wrap + h3,
.chapter-text .num-item + h2,
.chapter-text .num-item + h3 {
  margin-top: 38px;
}

.chapter-text strong {
  font-weight: 700;
  color: var(--ink);
}

.chapter-text em {
  font-style: italic;
}

.chapter-inline-img {
  display: block;
  width: 100%;
  max-width: 620px;
  margin: 28px auto !important;
  border-radius: var(--radius-md) !important;
  border: 1px solid var(--line-strong) !important;
  box-shadow: var(--shadow-soft);
}

.reader-artifact {
  display: none !important;
}

.reader-match {
  background: color-mix(in srgb, #ffe4a8 72%, var(--paper));
  box-shadow: 0 0 0 6px color-mix(in srgb, #ffe4a8 28%, transparent);
  border-radius: 6px;
  transition: box-shadow 0.3s ease, background 0.3s ease;
}

.page-viewer {
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: sticky;
  top: calc(var(--header-height) + 20px);
  max-height: calc(100vh - var(--header-height) - 40px);
  overflow-y: auto;
}

.page-viewer__img {
  width: 100%;
  max-width: 420px;
  margin: 0 auto;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: #fff;
  box-shadow: var(--shadow-soft);
  cursor: zoom-in;
}

.info-box,
.template-card,
.prompt-block {
  margin: 20px 0;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.info-box {
  padding: 16px 18px;
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
  font-family: var(--font-ui);
  font-size: 0.95rem;
}

.info-box--warning {
  border-left-color: var(--warning);
  background: color-mix(in srgb, #f5c28a 12%, var(--paper));
}

.info-box--success {
  border-left-color: var(--success);
  background: color-mix(in srgb, #8ec8a9 12%, var(--paper));
}

.info-box__title {
  margin-bottom: 6px;
  color: var(--brand-strong);
  font-weight: 700;
}

.table-wrap {
  margin: 24px 0 30px;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: color-mix(in srgb, var(--paper) 99%, transparent);
}

table {
  width: 100%;
  min-width: 560px;
  border-collapse: separate;
  border-spacing: 0;
  background: transparent;
  font-family: var(--font-ui);
  font-size: 0.98rem;
  line-height: 1.45;
}

thead th,
th {
  padding: 14px 16px;
  background: color-mix(in srgb, var(--brand-soft) 82%, #ffffff 18%);
  color: var(--ink);
  text-align: left;
  font-weight: 800;
  vertical-align: top;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line-strong);
}

thead th:last-child,
th:last-child {
  border-right: 0;
}

tbody td,
td {
  padding: 14px 16px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  color: var(--ink);
  background: color-mix(in srgb, var(--paper) 99%, transparent);
}

tbody td:last-child,
td:last-child {
  border-right: 0;
}

tbody tr:last-child td,
tr:last-child td {
  border-bottom: 0;
}

tbody tr:nth-child(even) td,
tr:nth-child(even) td {
  background: color-mix(in srgb, var(--brand-soft) 14%, #ffffff 86%);
}

.template-card,
.prompt-block {
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
}

.template-card__header,
.prompt-block__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 18px;
  background: color-mix(in srgb, var(--brand-soft) 74%, var(--paper));
  color: var(--brand-strong);
  font-weight: 700;
}

.template-card__body,
.prompt-block__body {
  padding: 18px;
}

.prompt-block__body {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.7;
  white-space: pre-wrap;
  word-break: break-word;
}

.checklist {
  list-style: none;
  padding: 0;
  margin: 18px 0 24px;
}

.checklist li {
  position: relative;
  padding: 8px 0 8px 28px;
  font-family: var(--font-ui);
  font-size: 1rem;
  line-height: 1.58;
  color: var(--ink);
}

.checklist li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--ink);
  font-weight: 800;
}

.book-visuals,
.chapter-visuals {
  margin: 28px auto 32px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  box-shadow: var(--shadow-soft);
}

.book-visuals__intro,
.chapter-visuals__intro {
  margin-bottom: 16px;
}

.book-visuals__eyebrow,
.chapter-visuals__eyebrow {
  display: inline-flex;
  margin-bottom: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--brand);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.book-visuals__intro p,
.chapter-visuals__intro p {
  margin: 0;
  color: var(--muted);
}

.book-visuals__grid,
.chapter-visuals__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  width: 100%;
}

.chapter-visuals--inline {
  max-width: 700px;
  margin: 28px auto 32px;
}

.chapter-visual {
  width: 100%;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--paper) 96%, transparent);
  box-shadow: var(--shadow-float);
}

.chapter-visual--wide {
  grid-column: 1 / -1;
}

.chapter-visual__media {
  width: 60%;
  margin: 0 auto;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper-strong) 90%, transparent);
  cursor: zoom-in;
}

.chapter-text img,
.book-visuals .chapter-visual__media {
  cursor: zoom-in;
}

.chapter-visual__caption {
  padding: 12px 14px 14px;
}

.chapter-visual__caption strong {
  display: block;
  margin-bottom: 4px;
  color: var(--brand-strong);
  font-size: 0.95rem;
}

.chapter-visual__caption span {
  color: var(--muted);
  font-size: 0.87rem;
  line-height: 1.5;
}

.page-nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 24px;
}

.page-nav a {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-height: 88px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  color: inherit;
  text-decoration: none;
  box-shadow: var(--shadow-soft);
}

.page-nav a:hover {
  border-color: var(--line-strong);
  transform: translateY(-1px);
}

.page-nav__label {
  color: var(--muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.page-nav__title {
  color: var(--brand-strong);
  font-weight: 700;
}

.page-nav__next {
  text-align: right;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 1300;
  padding: 12px 16px;
  border-radius: 14px;
  background: color-mix(in srgb, var(--brand) 92%, #111 8%);
  color: #fff;
  font-size: 0.9rem;
  box-shadow: var(--shadow-float);
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.2s ease, transform 0.2s ease;
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

.image-lightbox {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(8, 15, 43, 0.82);
  backdrop-filter: blur(8px);
  z-index: 1600;
}

.image-lightbox.open {
  display: flex;
}

.image-lightbox__frame {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: min(96vw, 1440px);
  max-height: 92vh;
}

.image-lightbox__img {
  display: block;
  max-width: 100%;
  max-height: 92vh;
  border-radius: 16px;
  box-shadow: 0 32px 80px rgba(0, 0, 0, 0.45);
  background: #fff;
}

.image-lightbox__close {
  position: absolute;
  top: -10px;
  right: -10px;
  width: 42px;
  height: 42px;
  border: 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.94);
  color: #111627;
  font: inherit;
  font-size: 1.35rem;
  cursor: pointer;
  box-shadow: var(--shadow-float);
}

.hidden {
  display: none !important;
}

@media (max-width: 1180px) {
  .reader-panels[data-mode="split"] {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-viewer {
    position: static;
    max-height: none;
  }
}

@media (max-width: 980px) {
  .library-panel {
    grid-template-columns: 1fr;
  }

  .hero {
    grid-template-columns: 1fr;
    text-align: center;
  }

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

@media (max-width: 860px) {
  .header__burger {
    display: inline-flex;
  }

  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.24s ease;
    box-shadow: var(--shadow-card);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .main {
    margin-left: 0;
    padding-left: 14px;
    padding-right: 14px;
  }

  .page-nav {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .header {
    padding: 0 12px;
  }

  .header__logo,
  .logo {
    font-size: 0.95rem;
  }

  .logo img {
    height: 28px;
  }

  .header__lang,
  .header__locale {
    padding: 8px 10px;
    font-size: 0.78rem;
  }

  .page-header,
  .chapter-text,
  .page-viewer,
  .toc,
  .hero,
  .library-card {
    border-radius: 18px;
  }

  .book-visuals,
  .chapter-visuals {
    padding: 14px;
  }

  .reader-toolbar__search {
    flex-direction: column;
  }

  .view-toggle {
    width: 100%;
  }
}

@media (max-width: 900px) {
  .chapter-text {
    font-size: 1rem;
    line-height: 1.64;
  }

  .chapter-text h2 {
    font-size: clamp(1.72rem, 5vw, 2.08rem);
  }

  .chapter-text h3 {
    font-size: clamp(1.2rem, 3.8vw, 1.48rem);
  }

  table {
    min-width: 520px;
    font-size: 0.94rem;
  }
}

@media (max-width: 767px) {
  .page-header h1 {
    font-size: clamp(1.75rem, 7vw, 2.3rem);
  }

  .chapter-text,
  .page-viewer {
    padding: 18px 16px;
  }

  .chapter-text p,
  .chapter-text .num-item,
  .chapter-text .bullet-item {
    margin-bottom: 16px;
  }

  .chapter-text .num-item {
    padding-left: 1.75rem;
  }

  .table-wrap {
    margin: 20px -4px 26px;
    border-radius: 10px;
  }

  table {
    min-width: 500px;
    font-size: 0.9rem;
  }

  thead th,
  th,
  tbody td,
  td {
    padding: 11px 12px;
  }

  .checklist li {
    padding-left: 24px;
  }

  .chapter-visual__media {
    width: 100%;
  }
}