:root {
  color-scheme: light;
  --parchment: #f5f4ed;
  --ivory: #faf9f5;
  --white: #ffffff;
  --sand: #e8e6dc;
  --border: #f0eee6;
  --border-strong: #e8e6dc;
  --ink: #141413;
  --charcoal: #30302e;
  --muted: #5e5d59;
  --stone: #87867f;
  --warm-silver: #b0aea5;
  --terracotta: #c96442;
  --coral: #d97757;
  --focus: #3898ec;
  --ring: #d1cfc5;
  --shadow: 0 4px 24px rgba(20, 20, 19, 0.05);
  --sidebar: 320px;
  --topbar: 72px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--parchment);
  color: var(--ink);
  font-family:
    "Inter",
    "Noto Sans SC",
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  line-height: 1.75;
}

a {
  color: var(--terracotta);
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: grid;
  grid-template-columns: auto minmax(180px, 1fr) minmax(220px, 360px);
  align-items: center;
  gap: 18px;
  height: var(--topbar);
  padding: 0 28px;
  border-bottom: 1px solid rgba(222, 215, 202, 0.85);
  background: rgba(245, 244, 237, 0.94);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  min-width: 0;
  gap: 12px;
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 0 0 1px rgba(201, 100, 66, 0.25);
}

.brand span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.icon-button,
.text-button,
.back-top {
  border: 1px solid var(--border-strong);
  background: var(--ivory);
  color: var(--ink);
  cursor: pointer;
}

.menu-button {
  display: none;
  width: 42px;
  height: 42px;
  padding: 10px;
  border-radius: 8px;
}

.menu-button span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--ink);
}

.text-button {
  padding: 8px 12px;
  border-radius: 7px;
}

.search {
  display: flex;
  align-items: center;
  gap: 10px;
  height: 42px;
  padding: 0 14px;
  border: 1px solid var(--border-strong);
  border-radius: 12px;
  background: var(--ivory);
  color: var(--muted);
  box-shadow: 0 0 0 1px rgba(209, 207, 197, 0.35);
}

.search span {
  white-space: nowrap;
}

.search input {
  width: 100%;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font: inherit;
}

.search:focus-within {
  border-color: var(--focus);
  box-shadow: 0 0 0 3px rgba(56, 152, 236, 0.15);
}

.shell {
  display: grid;
  grid-template-columns: var(--sidebar) minmax(0, 1fr);
  min-height: calc(100vh - var(--topbar));
}

.sidebar {
  position: sticky;
  top: var(--topbar);
  height: calc(100vh - var(--topbar));
  overflow: auto;
  padding: 24px 20px 32px;
  border-right: 1px solid var(--border-strong);
  background: #ebe8dd;
}

.sidebar-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.sidebar-head .text-button {
  display: none;
}

.toc {
  display: grid;
  gap: 2px;
}

.toc-group {
  display: grid;
  gap: 2px;
}

.toc a {
  display: block;
  padding: 8px 10px;
  border-radius: 7px;
  color: var(--ink);
  text-decoration: none;
}

.toc a.toc-chapter {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.toc-caret {
  flex: 0 0 auto;
  color: var(--stone);
  font-size: 1rem;
  line-height: 1;
  transform: rotate(0deg);
  transition: transform 160ms ease;
}

.toc-group.expanded .toc-caret {
  transform: rotate(90deg);
}

.toc a:hover,
.toc a.active {
  background: var(--ivory);
  box-shadow: 0 0 0 1px var(--ring);
  color: var(--ink);
}

.toc-children {
  display: none;
  gap: 1px;
  padding: 2px 0 6px;
}

.toc-group.expanded .toc-children {
  display: grid;
}

.toc-subgroup,
.toc-grandchildren {
  display: grid;
  gap: 1px;
}

.toc .level-2 {
  padding-left: 22px;
  color: var(--muted);
  font-size: 0.94rem;
}

.toc .level-3 {
  padding: 6px 10px 6px 38px;
  color: #74726b;
  font-size: 0.88rem;
  line-height: 1.45;
}

.reader {
  min-width: 0;
  padding: 42px clamp(20px, 5vw, 72px) 96px;
}

.search-results,
.content {
  width: min(100%, 920px);
  margin: 0 auto;
}

.cover {
  width: min(100%, 920px);
  margin: 0 auto;
  min-height: calc(100vh - var(--topbar) - 84px);
  display: flex;
  align-items: center;
  padding: 64px 0 82px;
  border-bottom: 1px solid var(--border-strong);
}

.cover-copy {
  min-width: 0;
}

.cover-logo {
  display: block;
  width: min(360px, 82vw);
  max-height: 120px;
  object-fit: contain;
  object-position: left center;
  margin: 18px 0 26px;
  mix-blend-mode: multiply;
}

.cover-mark,
.section-label {
  color: var(--terracotta);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0;
  text-transform: uppercase;
}

.cover h1 {
  max-width: 760px;
  margin: 12px 0 0;
  font-family: Georgia, "Times New Roman", "Noto Serif SC", serif;
  font-weight: 500;
  font-size: clamp(2.4rem, 6vw, 5.6rem);
  line-height: 1.08;
  letter-spacing: 0;
}

.edition {
  margin: 18px 0 0;
  font-size: 1.5rem;
  font-weight: 700;
}

.publisher {
  margin: 8px 0 0;
  color: var(--muted);
}

.notice {
  max-width: 700px;
  margin: 32px 0 0;
  padding: 18px 20px;
  border-left: 4px solid var(--terracotta);
  border-radius: 0 16px 16px 0;
  background: var(--ivory);
  color: var(--muted);
  box-shadow: 0 0 0 1px var(--border);
}

.chapter-visual {
  margin: 0;
}

.chapter-visual img {
  display: block;
  width: 100%;
  height: auto;
  max-height: min(72vh, 820px);
  border-radius: 24px;
  object-fit: contain;
  object-position: center;
  filter: saturate(0.88) sepia(0.08) contrast(0.96);
}

.chapter-visual figcaption {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 4px 0;
  color: var(--stone);
  font-size: 0.78rem;
  line-height: 1.35;
}

.chapter-visual figcaption a {
  color: var(--stone);
  overflow-wrap: anywhere;
}

.source-summary {
  max-width: 760px;
  margin-top: 24px;
  padding: 18px 20px;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  background: rgba(250, 249, 245, 0.7);
  box-shadow: 0 0 0 1px rgba(209, 207, 197, 0.45);
}

.source-summary ul {
  display: grid;
  gap: 6px;
  margin: 10px 0 0;
  padding-left: 1.2em;
}

.cover-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.primary-action,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 18px;
  border-radius: 8px;
  font-weight: 700;
  text-decoration: none;
}

.primary-action {
  background: var(--terracotta);
  color: #fff;
  box-shadow: 0 0 0 1px var(--terracotta);
}

.secondary-action {
  border: 1px solid var(--border-strong);
  background: var(--sand);
  color: var(--ink);
  box-shadow: 0 0 0 1px var(--ring);
}

.search-results {
  margin-top: 34px;
  padding: 24px;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  background: var(--ivory);
  box-shadow: var(--shadow);
}

.result-item {
  display: block;
  padding: 14px 0;
  border-top: 1px solid var(--border-strong);
  color: var(--ink);
  text-decoration: none;
}

.result-item:first-child {
  border-top: 0;
}

.result-title {
  display: block;
  font-weight: 800;
}

.result-snippet {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.95rem;
}

.content {
  padding-top: 48px;
  font-size: 1.07rem;
}

.content section {
  scroll-margin-top: calc(var(--topbar) + 22px);
}

.content h2,
.content h3 {
  font-family: Georgia, "Times New Roman", "Noto Serif SC", serif;
  font-weight: 500;
  line-height: 1.28;
  letter-spacing: 0;
}

.content h2 {
  margin: 80px 0 22px;
  padding-top: 10px;
  font-size: clamp(2.1rem, 4vw, 3.25rem);
}

.content h3 {
  margin: 42px 0 14px;
  font-size: clamp(1.45rem, 2.2vw, 2rem);
}

.content h4 {
  margin: 28px 0 10px;
  color: var(--charcoal);
  font-size: 1.08rem;
  font-weight: 800;
  line-height: 1.35;
}

.content p {
  margin: 0 0 1.05em;
}

.content strong,
.content-card strong {
  color: var(--ink);
  font-weight: 850;
  background: linear-gradient(transparent 58%, rgba(201, 100, 66, 0.18) 58%);
}

.content em,
.content-card em {
  color: #8f422a;
  font-style: italic;
  font-weight: 650;
}

.content-card {
  margin: 18px 0 24px;
  padding: 18px 20px;
  border: 1px solid var(--border-strong);
  border-left: 4px solid var(--terracotta);
  border-radius: 16px;
  background: var(--ivory);
  box-shadow: var(--shadow);
}

.content-card-title {
  margin-bottom: 8px;
  color: var(--terracotta);
  font-weight: 800;
}

.content-card ul {
  display: grid;
  gap: 6px;
  margin: 0;
}

.content-card.overview {
  background: #fffdf8;
  border-color: var(--border-strong);
  border-left-color: var(--charcoal);
}

.content-card.overview .content-card-title {
  color: var(--charcoal);
}

.chapter-visual {
  margin: 22px 0 34px;
  padding: 8px;
  border-radius: 24px;
  background: var(--ivory);
  box-shadow: var(--shadow), 0 0 0 1px var(--border-strong);
}

.content ul,
.content ol {
  padding-left: 1.4em;
}

.content li {
  margin: 0.25em 0;
}

.table-wrap {
  margin: 20px 0 28px;
  overflow-x: auto;
}

.content table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border: 1px solid var(--border-strong);
  background: var(--ivory);
  font-size: 0.95rem;
}

.content td,
.content th {
  vertical-align: top;
  padding: 12px 14px;
  border: 1px solid var(--border-strong);
}

.content th {
  background: #f0eee6;
  color: var(--charcoal);
  font-weight: 800;
  text-align: left;
}

.materials-table {
  table-layout: fixed;
}

.materials-table ul {
  display: grid;
  gap: 6px;
  margin: 0;
  padding-left: 1.1em;
}

.materials-table .fee-row td {
  background: #fffdf8;
}

.content blockquote,
.content .editor-note {
  margin: 22px 0;
  padding: 16px 18px;
  border-left: 4px solid var(--terracotta);
  background: #fff6e8;
  color: #5c3a13;
}

.loading {
  color: var(--muted);
}

.back-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 25;
  display: none;
  min-width: 54px;
  height: 42px;
  border-radius: 8px;
}

.back-top.visible {
  display: block;
}

body.menu-open {
  overflow: hidden;
}

@media (max-width: 920px) {
  body {
    overflow-x: hidden;
  }

  .topbar {
    grid-template-columns: auto minmax(0, 1fr);
    height: auto;
    min-height: var(--topbar);
    padding: 12px 16px;
  }

  .menu-button {
    display: block;
  }

  .search {
    grid-column: 1 / -1;
  }

  .shell {
    display: block;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 40;
    width: min(86vw, 340px);
    height: 100vh;
    transform: translateX(-105%);
    transition: transform 180ms ease;
    box-shadow: var(--shadow);
  }

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

  .sidebar-head .text-button {
    display: inline-flex;
  }

  .reader {
    overflow-x: hidden;
    padding: 24px 18px 82px;
  }

  .cover {
    min-height: calc(100vh - 130px);
    padding-top: 36px;
  }

  .cover-logo {
    width: min(300px, 78vw);
  }

  .chapter-visual figcaption {
    display: block;
  }

  .chapter-visual figcaption a {
    display: block;
  }

  .content {
    font-size: 1rem;
  }

  .content h2 {
    font-size: 1.65rem;
  }

  .source-summary {
    margin-top: 20px;
  }

  .content-card {
    padding: 14px 16px;
  }
}