/* 曾仕强《解密道德经》解读 - 索引页样式 */

:root {
  --bg: #fdfaf3;
  --bg-card: #ffffff;
  --fg: #2a2724;
  --fg-soft: #6b665f;
  --fg-light: #98928a;
  --accent: #8a4f2c;
  --accent-soft: #c79b7e;
  --line: #e8e0d2;
  --line-soft: #f1ebde;
  --shadow: 0 1px 2px rgba(60, 40, 20, 0.04), 0 4px 12px rgba(60, 40, 20, 0.06);
  --serif: "Songti SC", "STSong", "PingFang SC", "Source Han Serif SC", "Noto Serif CJK SC", serif;
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--serif);
  font-size: 16px;
  line-height: 1.7;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 站点头 */
.site-head {
  padding: 56px 0 32px;
  text-align: center;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, #fefcf6 0%, var(--bg) 100%);
}

.site-head h1 {
  font-size: 34px;
  font-weight: 600;
  letter-spacing: 4px;
  color: var(--fg);
  margin-bottom: 12px;
}

.site-head .lede {
  font-size: 14px;
  color: var(--fg-soft);
  letter-spacing: 1px;
  font-family: var(--sans);
  margin-bottom: 28px;
}

.tabs {
  display: inline-flex;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px;
  gap: 4px;
}

.tab {
  border: 0;
  background: transparent;
  padding: 8px 22px;
  font-family: var(--sans);
  font-size: 14px;
  color: var(--fg-soft);
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s;
  letter-spacing: 1px;
}

.tab:hover { color: var(--fg); }

.tab.active {
  background: var(--accent);
  color: #fff;
}

/* 视图切换 */
.view { display: none; padding: 40px 0 80px; }
.view.active { display: block; }

/* 主题导航 */
.topic-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 36px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--line-soft);
}

.topic-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: 999px;
  text-decoration: none;
  color: var(--fg);
  font-family: var(--sans);
  font-size: 13px;
  letter-spacing: 1px;
  transition: all 0.15s;
}

.topic-pill:hover {
  border-color: var(--accent-soft);
  color: var(--accent);
}

.topic-pill .ct {
  display: inline-block;
  min-width: 20px;
  padding: 1px 6px;
  background: var(--line-soft);
  border-radius: 999px;
  font-size: 11px;
  color: var(--fg-soft);
  text-align: center;
}

/* 主题区 */
.topic {
  margin-bottom: 56px;
  scroll-margin-top: 24px;
}

.topic-head {
  margin-bottom: 20px;
}

.topic-name {
  font-size: 22px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 3px;
  margin-bottom: 6px;
}

.topic-subtitle {
  font-size: 13px;
  color: var(--fg-soft);
  font-family: var(--sans);
  letter-spacing: 0.5px;
}

/* 章节网格 */
.ch-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 12px;
}

.ch-card {
  display: flex;
  gap: 14px;
  padding: 16px 18px;
  background: var(--bg-card);
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  text-decoration: none;
  color: var(--fg);
  transition: all 0.15s;
  align-items: flex-start;
}

.ch-card:hover {
  border-color: var(--accent-soft);
  box-shadow: var(--shadow);
  transform: translateY(-1px);
}

.ch-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--line-soft);
  color: var(--accent);
  font-family: var(--sans);
  font-weight: 600;
  font-size: 14px;
  border-radius: 6px;
  letter-spacing: 0;
}

.ch-card:hover .ch-num {
  background: var(--accent);
  color: #fff;
}

.ch-body { flex: 1; min-width: 0; }

.ch-title {
  font-size: 16px;
  font-weight: 500;
  margin-bottom: 4px;
  letter-spacing: 1px;
}

.ch-teaser {
  font-size: 13px;
  line-height: 1.55;
  color: var(--fg-soft);
  font-family: var(--sans);
  letter-spacing: 0.3px;
}

.ch-note {
  margin-top: 6px;
  font-size: 12px;
  color: #b25030;
  font-family: var(--sans);
}

/* 站点尾 */
.site-foot {
  border-top: 1px solid var(--line);
  padding: 32px 0;
  text-align: center;
}

.site-foot p {
  font-family: var(--sans);
  font-size: 12px;
  color: var(--fg-light);
  letter-spacing: 0.5px;
  line-height: 1.8;
}

/* ==================== 章节页 ==================== */

.page-chapter { background: var(--bg); }

.chapter-head {
  padding: 32px 0 24px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, #fefcf6 0%, var(--bg) 100%);
}

.breadcrumb {
  font-family: var(--sans);
  font-size: 13px;
  color: var(--fg-soft);
  margin-bottom: 16px;
  letter-spacing: 0.5px;
}

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

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

.breadcrumb .sep {
  margin: 0 10px;
  color: var(--fg-light);
}

.chapter-title {
  display: flex;
  align-items: baseline;
  gap: 18px;
  font-weight: 600;
  letter-spacing: 4px;
  color: var(--fg);
}

.chapter-num {
  font-family: var(--sans);
  font-size: 18px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 1px;
  padding: 4px 14px;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: 6px;
}

.chapter-name {
  font-size: 30px;
}

/* 章节布局：正文 + 右侧目录 */
.chapter-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: 56px;
  padding: 48px 24px 32px;
  align-items: start;
}

/* 正文 */
.chapter-body {
  font-size: 16px;
  line-height: 1.85;
  color: var(--fg);
}

.chapter-body h2 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: 2px;
  color: var(--accent);
  margin: 48px 0 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--line);
  scroll-margin-top: 24px;
}

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

.chapter-body h3 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 1px;
  color: var(--fg);
  margin: 32px 0 12px;
  scroll-margin-top: 24px;
}

.chapter-body p {
  margin: 14px 0;
}

.chapter-body strong {
  color: var(--accent);
  font-weight: 600;
}

.chapter-body em {
  font-style: normal;
  color: var(--accent);
}

/* 引用 - 用来显示道德经原文 */
.chapter-body blockquote {
  margin: 20px 0;
  padding: 18px 24px;
  background: #f7f1e3;
  border-left: 4px solid var(--accent-soft);
  border-radius: 0 6px 6px 0;
  font-family: var(--serif);
  font-size: 16.5px;
  line-height: 2.0;
  color: var(--fg);
  letter-spacing: 1px;
}

.chapter-body blockquote p {
  margin: 4px 0;
}

/* 列表 */
.chapter-body ul,
.chapter-body ol {
  margin: 14px 0;
  padding-left: 28px;
}

.chapter-body li {
  margin: 6px 0;
}

.chapter-body li::marker {
  color: var(--accent-soft);
}

/* 表格 */
.chapter-body table {
  width: 100%;
  margin: 20px 0;
  border-collapse: collapse;
  font-size: 14px;
  background: var(--bg-card);
  border-radius: 6px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.chapter-body thead {
  background: #f4ecd9;
}

.chapter-body th,
.chapter-body td {
  padding: 10px 14px;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
  line-height: 1.6;
}

.chapter-body th {
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.5px;
}

.chapter-body td:first-child {
  white-space: nowrap;
  font-weight: 500;
}

/* 分隔线 */
.chapter-body hr {
  margin: 40px 0;
  border: 0;
  border-top: 1px dashed var(--line);
}

/* 代码 */
.chapter-body code {
  background: var(--line-soft);
  color: var(--accent);
  padding: 1px 6px;
  border-radius: 3px;
  font-size: 14px;
  font-family: ui-monospace, "SF Mono", Monaco, monospace;
}

/* 链接 */
.chapter-body a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: var(--accent-soft);
  text-underline-offset: 3px;
}

.chapter-body a:hover { text-decoration-thickness: 2px; }

/* 右侧目录 */
.chapter-toc {
  position: relative;
  font-family: var(--sans);
}

.toc-sticky {
  position: sticky;
  top: 24px;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--line-soft);
  border-radius: 8px;
}

.toc-head {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 2px;
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line-soft);
}

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

.toc-list li {
  margin: 8px 0;
}

.toc-list a {
  display: block;
  font-size: 13px;
  color: var(--fg-soft);
  text-decoration: none;
  padding: 4px 8px;
  border-radius: 4px;
  line-height: 1.5;
  letter-spacing: 0.5px;
  transition: all 0.15s;
}

.toc-list a:hover {
  background: var(--line-soft);
  color: var(--accent);
}

.toc-actions {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--line-soft);
}

.toc-home {
  display: block;
  text-align: center;
  font-size: 12px;
  color: var(--fg-soft);
  text-decoration: none;
  padding: 8px;
  border-radius: 4px;
  transition: all 0.15s;
  letter-spacing: 1px;
}

.toc-home:hover {
  background: var(--line-soft);
  color: var(--accent);
}

/* 底部章节导航 */
.chapter-nav {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 12px;
  padding: 24px;
  margin-top: 40px;
  border-top: 1px solid var(--line);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: var(--bg-card);
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  text-decoration: none;
  color: var(--fg);
  transition: all 0.15s;
  font-family: var(--sans);
}

.nav-link:hover:not(.nav-disabled) {
  border-color: var(--accent-soft);
  box-shadow: var(--shadow);
  color: var(--accent);
}

.nav-disabled {
  opacity: 0.4;
  cursor: default;
}

.nav-prev { justify-content: flex-start; }
.nav-next { justify-content: flex-end; text-align: right; }
.nav-home { justify-content: center; padding: 14px 24px; }

.nav-arrow {
  font-size: 18px;
  color: var(--accent);
}

.nav-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.nav-meta {
  font-size: 11px;
  color: var(--fg-light);
  letter-spacing: 1px;
}

.nav-title {
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 1px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 移动端 */
@media (max-width: 640px) {
  .container { padding: 0 16px; }
  .site-head { padding: 36px 0 24px; }
  .site-head h1 { font-size: 26px; letter-spacing: 2px; }
  .topic-name { font-size: 18px; }
  .ch-grid { grid-template-columns: 1fr; }
  .view { padding: 24px 0 60px; }

  .chapter-layout {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 24px 16px;
  }

  .chapter-toc { display: none; }

  .chapter-title {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .chapter-name { font-size: 22px; letter-spacing: 2px; }

  .chapter-body { font-size: 15px; }

  .chapter-body h2 { font-size: 18px; margin-top: 32px; }

  .chapter-body table { font-size: 13px; }

  .chapter-body th,
  .chapter-body td { padding: 8px 10px; }

  .chapter-nav {
    grid-template-columns: 1fr 1fr;
    padding: 16px;
  }

  .nav-home { display: none; }
}

@media (max-width: 980px) and (min-width: 641px) {
  .chapter-layout { grid-template-columns: 1fr; }
  .chapter-toc { display: none; }
}