:root {
  --bg: #f4f1ea;
  --panel: #fbf9f4;
  --ink: #23211c;
  --ink-soft: #6c655a;
  --line: #ddd6c8;
  --accent: #7a3b2e;
  --accent-soft: #a86a5c;
  --max: 42rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16151320;
    --bg: #161513;
    --panel: #1e1c19;
    --ink: #e6e1d6;
    --ink-soft: #9a9286;
    --line: #322e29;
    --accent: #d79a86;
    --accent-soft: #b97f6d;
  }
}

* {
  box-sizing: border-box;
}

html {
  font-size: 17px;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Hiragino Mincho ProN", "Yu Mincho", "YuMincho", "Noto Serif JP",
    serif;
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

/* ---- 目次 ---- */
.site-header {
  text-align: center;
  border-bottom: 1px solid var(--line);
  padding-bottom: 1.5rem;
  margin-bottom: 2rem;
}

.site-title {
  font-size: 1.9rem;
  letter-spacing: 0.08em;
  margin: 0 0 0.4rem;
}

.site-meta {
  color: var(--ink-soft);
  font-size: 0.85rem;
  margin: 0;
}

.breadcrumb {
  margin: 0 0 0.6rem;
  font-size: 0.8rem;
}

.breadcrumb a {
  color: var(--accent-soft);
  text-decoration: none;
}

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

/* ---- 本棚（作品一覧） ---- */
.novel-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.novel-item {
  border-bottom: 1px solid var(--line);
}

.novel-link {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.1rem 0.5rem;
  text-decoration: none;
  color: var(--ink);
  transition: background 0.15s ease;
}

.novel-link:hover {
  background: var(--panel);
}

.novel-title {
  font-size: 1.15rem;
  letter-spacing: 0.04em;
}

.novel-meta {
  flex: 0 0 auto;
  color: var(--ink-soft);
  font-size: 0.8rem;
  font-variant-numeric: tabular-nums;
}

.episode-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.episode-item {
  border-bottom: 1px solid var(--line);
}

.episode-link {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  padding: 0.85rem 0.5rem;
  text-decoration: none;
  color: var(--ink);
  transition: background 0.15s ease;
}

.episode-link:hover {
  background: var(--panel);
}

.episode-num {
  flex: 0 0 auto;
  min-width: 3.2em;
  font-variant-numeric: tabular-nums;
  font-family: "SFMono-Regular", "Menlo", monospace;
  font-size: 0.85rem;
  color: var(--accent-soft);
  letter-spacing: 0.04em;
}

.episode-title {
  flex: 1 1 auto;
}

/* ---- 各話本文 ---- */
.episode {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 2.5rem 2rem;
  margin: 1.25rem 0;
}

.episode h1 {
  font-size: 1.5rem;
  letter-spacing: 0.06em;
  text-align: center;
  margin: 0 0 2rem;
  padding-bottom: 1.2rem;
  border-bottom: 1px solid var(--line);
}

.episode p {
  margin: 0 0 1.4rem;
  text-align: justify;
  word-break: normal;
  line-break: strict;
  overflow-wrap: break-word;
}

.episode h2,
.episode h3 {
  letter-spacing: 0.04em;
  margin: 2.2rem 0 1rem;
}

/* ---- 前へ / 次へ ナビ（NavigationCard） ---- */
.episode-nav {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: stretch;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--panel);
  overflow: hidden;
}

.episode-nav.top {
  margin-bottom: 1.25rem;
}

.episode-nav.bottom {
  margin-top: 1.25rem;
}

.nav-btn {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.7rem 1rem;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
  min-width: 0;
  transition: background 0.15s ease, color 0.15s ease;
}

/* セル同士は区切り線で仕切る（個別カードにはしない） */
.nav-index,
.nav-next {
  border-left: 1px solid var(--line);
}

.nav-btn:hover {
  background: var(--bg);
}

.nav-prev {
  justify-content: flex-end;
}

.nav-next {
  justify-content: flex-start;
}

.nav-index {
  justify-content: center;
  flex: 0 0 auto;
  white-space: nowrap;
  color: var(--ink-soft);
}

.nav-dir {
  flex: 0 0 auto;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.nav-label {
  font-size: 0.78rem;
  color: var(--ink-soft);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.nav-btn.disabled {
  color: var(--line);
  cursor: default;
  pointer-events: none;
}

@media (max-width: 30rem) {
  .episode {
    padding: 1.75rem 1.2rem;
  }
  .nav-label {
    display: none;
  }
}