:root {
  --color-background: #f8f3e8;
  --color-surface: #ffffff;
  --color-text-primary: #2a2a2a;
  --color-text-secondary: #5c4a3f;
  --color-accent: #a45a32;
  --color-highlight: #2f6b5a;
  --color-border: rgba(90, 66, 49, 0.2);
  --shadow-elevated: 0 18px 40px rgba(42, 35, 28, 0.08);
  --font-title: "Source Han Serif SC", "Songti SC", "Noto Serif SC", serif;
  --font-body: "Source Han Serif SC", "Noto Serif SC", "STSong", serif;
  --layout-max-width: 1080px;
  --transition-default: all 0.3s ease;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.75;
  color: var(--color-text-primary);
  background: var(--color-background);
  letter-spacing: 0.02em;
}

a {
  color: var(--color-highlight);
  text-decoration: none;
  transition: var(--transition-default);
}

a:hover,
a:focus {
  color: var(--color-accent);
}

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

.site-header {
  background: linear-gradient(120deg, rgba(47, 107, 90, 0.12), rgba(164, 90, 50, 0.12));
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(10px);
}

.site-header-inner {
  display: flex;
  gap: 32px;
  align-items: center;
  justify-content: space-between;
  max-width: var(--layout-max-width);
  margin: 0 auto;
  padding: 18px 24px;
}

.site-brand {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.site-brand-title {
  font-family: var(--font-title);
  font-size: 26px;
  letter-spacing: 0.18em;
}

.site-brand-subtitle {
  font-size: 14px;
  color: var(--color-text-secondary);
  letter-spacing: 0.24em;
}

.site-nav {
  display: flex;
  gap: 18px;
}

.site-nav a {
  padding: 6px 12px;
  border-radius: 99px;
  font-size: 16px;
  color: var(--color-text-secondary);
}

.site-nav a[aria-current="page"],
.site-nav a:hover {
  color: var(--color-highlight);
  background: rgba(47, 107, 90, 0.12);
}

.hero {
  position: relative;
  padding: 96px 24px 72px;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: url('data:image/svg+xml,%3Csvg width="800" height="800" viewBox="0 0 800 800" xmlns="http://www.w3.org/2000/svg"%3E%3Cg fill="none" fill-rule="evenodd" opacity="0.2"%3E%3Cpath d="M400 0l51.962 160.498h168.038l-135.799 98.552 51.96 160.498L400 321.996 263.84 419.548l51.959-160.498L180 160.498h168.039z" stroke="%232f6b5a" stroke-width="1"/%3E%3C/g%3E%3C/svg%3E');
  background-size: cover;
  opacity: 0.16;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: var(--layout-max-width);
  margin: 0 auto;
  display: grid;
  gap: 36px;
  background: rgba(255, 255, 255, 0.78);
  border-radius: 24px;
  padding: 48px;
  border: 1px solid rgba(47, 107, 90, 0.16);
  box-shadow: var(--shadow-elevated);
}

.hero-title {
  font-family: var(--font-title);
  font-size: 48px;
  margin: 0;
  color: var(--color-highlight);
  text-align: center;
  letter-spacing: 0.24em;
}

.hero-subtitle {
  margin: 0 auto;
  max-width: 640px;
  text-align: center;
  font-size: 18px;
  color: var(--color-text-secondary);
}

.hero-actions {
  display: flex;
  gap: 18px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 16px;
  cursor: pointer;
  transition: var(--transition-default);
}

.btn-primary {
  background: var(--color-highlight);
  color: #ffffff;
  box-shadow: 0 12px 22px rgba(47, 107, 90, 0.3);
}

.btn-primary:hover {
  background: #255445;
}

.btn-secondary {
  background: rgba(164, 90, 50, 0.12);
  color: var(--color-accent);
  border-color: rgba(164, 90, 50, 0.24);
}

.section {
  max-width: var(--layout-max-width);
  margin: 0 auto;
  padding: 48px 24px;
}

.section-title {
  font-family: var(--font-title);
  font-size: 32px;
  margin-bottom: 24px;
  letter-spacing: 0.18em;
}

.section-description {
  font-size: 18px;
  color: var(--color-text-secondary);
  max-width: 720px;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  margin-top: 32px;
}

.card {
  background: rgba(255, 255, 255, 0.94);
  padding: 32px;
  border-radius: 20px;
  border: 1px solid var(--color-border);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.04);
  transition: var(--transition-default);
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 24px 42px rgba(42, 35, 28, 0.08);
}

.card-title {
  font-size: 22px;
  font-family: var(--font-title);
  margin: 0;
}

.card-meta {
  font-size: 14px;
  color: var(--color-text-secondary);
  letter-spacing: 0.08em;
}

.card-summary {
  margin: 0;
  color: var(--color-text-secondary);
}

.card-actions {
  margin-top: auto;
}

.content-wrapper {
  max-width: 960px;
  margin: 0 auto;
  padding: 48px 24px;
}

.breadcrumbs {
  font-size: 14px;
  margin-bottom: 24px;
  color: var(--color-text-secondary);
}

.page-title {
  font-family: var(--font-title);
  font-size: 38px;
  margin: 0 0 12px;
  letter-spacing: 0.16em;
}

.page-intro {
  margin: 0 0 32px;
  color: var(--color-text-secondary);
  max-width: 720px;
}

.print-notice {
  background: rgba(47, 107, 90, 0.08);
  border: 1px solid rgba(47, 107, 90, 0.24);
  padding: 18px 24px;
  border-radius: 16px;
  color: var(--color-highlight);
  margin-bottom: 32px;
}

.layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 32px;
}

.toc {
  position: sticky;
  top: 120px;
  align-self: start;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 24px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--color-border);
}

.toc-title {
  margin: 0 0 12px;
  font-size: 18px;
  font-family: var(--font-title);
}

.toc a {
  font-size: 15px;
  color: var(--color-text-secondary);
}

.toc a:hover,
.toc a:focus {
  color: var(--color-highlight);
}

.article {
  display: grid;
  gap: 24px;
}

.segment {
  background: rgba(255, 255, 255, 0.94);
  border-radius: 16px;
  border: 1px solid var(--color-border);
  padding: 24px 28px;
  box-shadow: 0 12px 20px rgba(0, 0, 0, 0.04);
}

.segment-title {
  margin: 0 0 12px;
  font-size: 20px;
  font-family: var(--font-title);
  color: var(--color-highlight);
}

.segment-content {
  display: grid;
  gap: 18px;
}

.segment-phrase {
  font-size: 24px;
  font-family: var(--font-title);
}

.segment-phrase ruby {
  font-size: 32px;
  letter-spacing: 0.12em;
}

.segment-phrase rt {
  font-size: 16px;
  color: var(--color-text-secondary);
  letter-spacing: 0.18em;
}

.segment-notes {
  margin: 0;
  font-size: 16px;
  color: var(--color-text-secondary);
}

.pagination {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--color-border);
  padding-top: 24px;
  margin-top: 48px;
  gap: 18px;
}

.pagination a {
  padding: 10px 20px;
  border-radius: 999px;
  background: rgba(164, 90, 50, 0.12);
  color: var(--color-accent);
}

.pagination a:hover {
  background: rgba(164, 90, 50, 0.2);
}

.page-footer {
  padding: 48px 24px;
  background: rgba(47, 107, 90, 0.12);
  color: var(--color-text-secondary);
}

.page-footer-inner {
  max-width: var(--layout-max-width);
  margin: 0 auto;
  display: grid;
  gap: 12px;
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--color-highlight);
  color: #ffffff;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 12px 22px rgba(47, 107, 90, 0.35);
  opacity: 0;
  pointer-events: none;
  transition: var(--transition-default);
  z-index: 30;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

@media (max-width: 1024px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .toc {
    position: relative;
    top: auto;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 8px 16px;
  }

  .hero-inner {
    padding: 32px;
  }

  .hero-title {
    font-size: 36px;
  }
}

@media (max-width: 720px) {
  body {
    font-size: 17px;
  }

  .site-header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 18px;
  }

  .site-nav {
    width: 100%;
    flex-wrap: wrap;
  }

  .hero {
    padding: 72px 18px 48px;
  }

  .hero-inner {
    padding: 24px;
  }

  .hero-title {
    font-size: 30px;
  }

  .segment {
    padding: 18px 20px;
  }
}

@media print {
  body {
    background: #ffffff;
    color: #111111;
  }

  .site-header,
  .hero,
  .toc,
  .print-notice,
  .pagination,
  .page-footer,
  .back-to-top {
    display: none !important;
  }

  .content-wrapper,
  .layout,
  .article,
  .segment {
    box-shadow: none;
    border: none;
    padding: 0;
  }

  .segment {
    page-break-inside: avoid;
  }

  @page {
    margin: 18mm 16mm 20mm;
  }
}