/* KRen 狂人心学@入门课 — 书籍版式
   继承 gottao 品牌 (../blog-article.css) 的变量与排版，
   新增：左侧章节树、面包屑、上下章导航、Part 卡片、章末标记。
   部署路径：gottao.com/KRen-two-book/kren-book.css */

:root {
  --sidebar-w: 18rem;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Serif SC", "Songti SC", serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background: linear-gradient(180deg, #fbfbff 0%, #ffffff 26rem), #ffffff;
}

a, a:hover, a:focus { text-decoration: none; }

/* ---- 顶部导航（沿用 gottao） ---- */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  border-bottom: 1px solid rgba(237, 233, 254, .7);
  background: rgba(255, 255, 255, .9);
  backdrop-filter: blur(12px);
}
.article-nav {
  max-width: 84rem;
  height: 4rem;
  margin: 0 auto;
  padding: 0 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.brand-mark {
  display: inline-flex; align-items: center; gap: .5rem;
  color: var(--ink); font-size: 1.125rem; font-weight: 800;
}
.brand-mark img {
  width: 1.75rem; height: 1.75rem; border-radius: .5rem;
  box-shadow: 0 10px 24px -12px rgba(131, 76, 214, .7);
}
.article-nav-links {
  display: flex; align-items: center; gap: 1.75rem;
  font-size: .875rem; font-weight: 500;
}
.article-nav-links a { color: #4b5563; }
.article-nav-links a:hover, .article-nav-links a.is-active { color: var(--brand); font-weight: 600; }
.brand-accent { color: var(--brand); }
.nav-cta {
  padding: .5rem 1rem; color: #fff; font-weight: 600; font-size: .875rem;
  border-radius: 999px; box-shadow: 0 10px 24px -12px rgba(107, 70, 193, .5); transition: opacity .2s ease;
}
.nav-cta.hero-grad { background: linear-gradient(283.01deg, #834CD6 8.03%, #9546E2 34.85%, #B935D9 100%); }
.nav-cta:hover { opacity: .95; }

/* ---- Books 下拉 ---- */
.nav-dropdown { position: relative; }
.nav-dropdown-trigger {
  display: inline-flex; align-items: center; gap: .25rem; padding: 0;
  border: none; background: none; color: #4b5563;
  font: inherit; font-size: .875rem; font-weight: 500; cursor: pointer; transition: color .2s ease;
}
.nav-dropdown-trigger:hover, .nav-dropdown:focus-within .nav-dropdown-trigger { color: var(--brand); }
.nav-dropdown-trigger.is-active { color: var(--brand); font-weight: 600; }
.nav-dropdown-chevron { width: .875rem; height: .875rem; opacity: .5; }
.nav-dropdown-panel {
  position: absolute; left: 50%; top: 100%; z-index: 50; padding-top: .5rem;
  opacity: 0; visibility: hidden; pointer-events: none;
  transform: translateX(-50%) translateY(6px); transition: opacity .2s, transform .2s, visibility .2s;
}
.nav-dropdown:hover .nav-dropdown-panel, .nav-dropdown:focus-within .nav-dropdown-panel {
  opacity: 1; visibility: visible; pointer-events: auto; transform: translateX(-50%) translateY(0);
}
.nav-dropdown-menu {
  min-width: 16rem; padding: .5rem 0;
  border: 1px solid rgba(237, 233, 254, .8); border-radius: .75rem; background: #fff;
  box-shadow: 0 20px 50px -24px rgba(91, 33, 182, .35);
}
.nav-dropdown-menu a {
  display: block; margin: 0 .25rem; padding: .65rem 1rem; border-radius: .5rem;
  color: var(--ink);
}
.nav-dropdown-menu a:hover { background: var(--brand-soft); color: var(--brand-strong); }
.nav-dropdown-menu a.is-active { background: var(--brand-soft); }
.nav-dropdown-item-title { display: block; font-weight: 700; line-height: 1.35; }
.nav-dropdown-item-desc { display: block; margin-top: .15rem; color: var(--muted); font-size: .75rem; font-weight: 500; line-height: 1.4; }

/* ---- 书籍布局 ---- */
.book-layout {
  max-width: 84rem;
  margin: 0 auto;
  padding: 5rem 1.25rem 4rem;
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  gap: 2.5rem;
  align-items: start;
}

/* ---- 侧栏 ---- */
.book-sidebar {
  position: sticky; top: 5rem; max-height: calc(100vh - 6rem);
  overflow-y: auto; padding-right: .5rem;
}
.book-sidebar-title {
  display: block; margin-bottom: 1rem; padding-bottom: .75rem;
  border-bottom: 1px solid var(--line);
  color: var(--ink); font-size: 1rem; font-weight: 900;
}
.book-toc { font-size: .875rem; }
.book-toc .toc-part {
  margin: 1.1rem 0 .35rem; color: var(--brand-strong);
  font-size: .72rem; font-weight: 900; letter-spacing: .04em; text-transform: uppercase;
}
.book-toc ul { margin: 0; padding: 0; list-style: none; }
.book-toc a {
  display: block; padding: .34rem .6rem; border-radius: .5rem;
  color: #475569; line-height: 1.5; transition: background .15s, color .15s;
}
.book-toc a:hover { background: var(--brand-soft); color: var(--brand-strong); }
.book-toc a.is-current { background: var(--brand-soft); color: var(--brand-strong); font-weight: 700; }
.book-toc .toc-num { color: var(--muted); font-weight: 700; margin-right: .3rem; }
.book-toc a.is-current .toc-num { color: var(--brand); }
.book-sidebar-toggle {
  display: none; position: fixed; right: 1rem; bottom: 1rem; z-index: 60;
  padding: .6rem 1rem; border: none; border-radius: 999px;
  background: var(--brand); color: #fff; font-weight: 700; font-size: .9rem;
  box-shadow: 0 12px 28px -12px rgba(124, 58, 237, .8); cursor: pointer;
}

/* ---- 阅读区 ---- */
.book-main { min-width: 0; }
.book-article { max-width: 54rem; }
.book-breadcrumb {
  display: inline-flex; align-items: center; gap: .5rem;
  margin-bottom: 1.5rem; color: var(--brand-strong); font-size: .82rem; font-weight: 800;
}
.book-breadcrumb a { color: var(--brand-strong); }
.book-breadcrumb a:hover { color: var(--brand); }
.book-breadcrumb .sep { color: var(--line); }

.book-byline {
  margin: 0 0 2rem; padding: 1.1rem 1.35rem;
  border-left: 4px solid var(--brand);
  border-radius: .5rem;
  background: linear-gradient(180deg, #faf8ff 0%, #f6f3ff 100%);
  color: #4c1d95; font-weight: 500; line-height: 1.8;
  font-style: normal;
}
.book-byline strong { color: var(--brand-strong); font-weight: 800; }

/* Inline compact byline (chapter pages, replaces purple aside) */
.book-byline-inline {
  margin: 0 0 1.4rem; padding: 0;
  color: var(--muted); font-size: .92rem;
  font-style: normal; line-height: 1.6;
}
.book-byline-inline strong { color: var(--brand-strong); font-weight: 700; }
.book-byline-inline .sep { color: var(--line); margin: 0 .5rem; }

.book-end {
  margin-top: 3rem; padding-top: 1.5rem;
  border-top: 1px dashed var(--line);
  text-align: center; color: var(--muted); font-size: .9rem; font-style: italic;
}

/* ---- 正文 ---- */
.book-body { color: #374151; font-size: 1.05rem; line-height: 1.95; }
.book-body > h1:first-child { margin-top: 0; }
.book-body h1 {
  margin: 0 0 1.4rem; color: var(--ink);
  font-size: clamp(1.6rem, 3vw, 2.2rem); line-height: 1.2; font-weight: 800; letter-spacing: -0.01em;
}
.book-body h2 {
  margin: 2.4rem 0 .9rem; color: var(--ink);
  font-size: clamp(1.25rem, 2vw, 1.5rem); line-height: 1.3; font-weight: 750; letter-spacing: -0.005em;
}
.book-body h3 {
  margin: 1.6rem 0 .6rem; color: var(--ink);
  font-size: 1.05rem; line-height: 1.4; font-weight: 700;
}
.book-body p { margin: 1.05rem 0; }
.book-body a { color: var(--brand-strong); font-weight: 600; }
.book-body a:hover { color: var(--brand); }
.book-body strong { color: var(--ink); }
.book-body ul, .book-body ol { margin: 1.25rem 0; padding-left: 1.4rem; }
.book-body ul { list-style: none; padding-left: 0; }
.book-body ul > li {
  position: relative; margin: .6rem 0; padding-left: 1.3rem; color: #475569; line-height: 1.85;
}
.book-body ul > li::before {
  content: ""; position: absolute; top: .78em; left: 0;
  width: .42rem; height: .42rem; border-radius: 999px; background: var(--teal);
}
.book-body ol > li { margin: .6rem 0; color: #475569; line-height: 1.85; }
.book-body blockquote {
  position: relative; margin: 1.9rem 0; padding: 1.15rem 1.35rem 1.15rem 3.1rem;
  border: 1px solid #ece9fe; border-left: 4px solid var(--brand);
  border-radius: .875rem; background: linear-gradient(180deg, #faf8ff 0%, #f6f3ff 100%);
  color: #4c1d95; font-weight: 600; line-height: 1.8;
}
.book-body blockquote::before {
  content: "“"; position: absolute; top: .35rem; left: 1rem;
  color: #c4b5fd; font-size: 2.4rem; font-weight: 900; line-height: 1;
  font-family: Georgia, "Times New Roman", serif;
}
.book-body blockquote p { margin: .4rem 0; }
.book-body .book-figure {
  margin: 1.8rem auto;
  max-width: 100%;
}
.book-body .book-figure img {
  display: block;
  width: 100%;
  max-width: min(100%, 42rem);
  height: auto;
  max-height: calc(100vh - 8rem);
  margin: 0 auto;
  object-fit: contain;
  border-radius: .875rem;
  border: 1px solid var(--line);
  background: #fff;
  box-shadow: 0 22px 52px -38px rgba(15, 23, 42, .4);
}
.book-body :not(pre) > code {
  padding: .16rem .4rem; border: 1px solid #e2e8f0; border-radius: .45rem;
  background: #f8fafc; color: #b91c8c; font-size: .9em;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
.book-body hr { margin: 2.5rem 0; border: none; border-top: 1px solid var(--line); }

/* ---- 上下章 ---- */
.book-pager {
  display: flex; justify-content: space-between; gap: 1rem;
  margin-top: 3.5rem; padding-top: 1.75rem; border-top: 1px solid var(--line);
}
.book-pager a {
  flex: 1; max-width: 48%; padding: 1rem 1.15rem;
  border: 1px solid var(--line); border-radius: .875rem; transition: border-color .15s, box-shadow .15s;
}
.book-pager a:hover { border-color: #ddd6fe; box-shadow: 0 16px 36px -30px rgba(124, 58, 237, .8); }
.book-pager .pager-dir { font-size: .75rem; font-weight: 800; color: var(--muted); }
.book-pager .pager-title { display: block; margin-top: .3rem; color: var(--ink); font-weight: 800; }
.book-pager .pager-next { text-align: right; margin-left: auto; }

/* ---- 主页（index）---- */
.book-layout.book-layout-index {
  grid-template-columns: minmax(0, 1fr);
  padding-top: 5rem;
}
.book-layout.book-layout-index .book-sidebar-toggle { display: none; }
.book-cover {
  margin-bottom: 1.5rem; padding: 1.6rem 1.8rem; border-radius: 1.25rem; color: #fff;
  box-shadow: 0 26px 70px -42px rgba(109, 40, 217, .9);
  background: linear-gradient(283.01deg, #834CD6 8.03%, #9546E2 34.85%, #B935D9 100%);
}
.book-cover h1 { margin: 0 0 .5rem; font-size: clamp(1.45rem, 2.4vw, 1.85rem); line-height: 1.2; font-weight: 850; letter-spacing: -0.005em; }
.book-cover p { margin: 0; color: rgba(255,255,255,.88); font-size: 1rem; line-height: 1.6; }
.book-cover .book-cover-meta { margin-top: .75rem; display: flex; flex-wrap: wrap; gap: .35rem; }
.book-cover .book-cover-meta span {
  padding: .18rem .55rem; border-radius: 999px;
  background: rgba(255,255,255,.15); color: rgba(255,255,255,.95);
  font-size: .78rem; font-weight: 600;
}
.book-meta {
  margin: 1.25rem 0 1.5rem; padding: 1rem 1.25rem;
  border: 1px solid var(--line); border-radius: .875rem; background: #fbfaff; font-size: .92rem;
}
.book-meta-row { display: flex; gap: .75rem; padding: .3rem 0; line-height: 1.6; }
.book-meta-row + .book-meta-row { border-top: 1px solid #f1eefe; }
.book-meta-key { flex: 0 0 5.5rem; color: var(--muted); font-weight: 700; }
.book-meta-val { color: var(--ink); min-width: 0; overflow-wrap: anywhere; }
.book-meta-val a { color: var(--brand-strong); font-weight: 600; }
.book-meta-val a:hover { color: var(--brand); }

.book-parts-grid { display: grid; gap: 1rem; margin: 1.5rem 0; }
.book-part-card {
  padding: 1.25rem 1.4rem; border: 1px solid var(--line); border-radius: 1rem; background: #fff;
}
.book-part-card h3 { margin: 0 0 .35rem; font-size: 1.05rem; font-weight: 900; color: var(--ink); }
.book-part-card .part-theme { margin: 0 0 .6rem; color: var(--muted); font-size: .9rem; }
.book-part-card .part-chapters { display: flex; flex-wrap: wrap; gap: .4rem; }
.book-part-card .part-chapters a {
  padding: .25rem .6rem; border-radius: 999px; background: var(--brand-soft);
  color: var(--brand-strong); font-size: .8rem; font-weight: 600;
}
.book-part-card .part-chapters a:hover { background: #ede9fe; }

/* ---- 响应式 ---- */
@media (max-width: 960px) {
  .book-layout { grid-template-columns: 1fr; padding-top: 4.5rem; }
  .book-sidebar {
    position: fixed; top: 0; left: 0; bottom: 0; width: 16rem;
    max-height: 100vh; padding: 5rem 1rem 2rem;
    background: #fff; border-right: 1px solid var(--line);
    box-shadow: 0 0 60px -20px rgba(15,23,42,.3);
    transform: translateX(-105%); transition: transform .25s ease; z-index: 55;
  }
  .book-sidebar.is-open { transform: translateX(0); }
  .book-sidebar-toggle { display: block; }
}
@media (max-width: 860px) { .article-nav-links { display: none; } }
@media (max-width: 640px) {
  .article-nav { padding: 0 1rem; }
  .book-body { font-size: 1rem; }
  .book-body .book-figure {
    margin-left: -0.15rem;
    margin-right: -0.15rem;
  }
  .book-body .book-figure img {
    max-width: 100%;
    max-height: none;
    border-radius: .65rem;
  }
  .book-pager { flex-direction: column; }
  .book-pager a { max-width: 100%; }
  .book-cover { padding: 1.6rem; }
}

/* === KRen Book CSS v3 增量（2026-07-06）===
   旧 class 全部保留；只追加新 class。 */

/* 章首 hero */
.book-chapter-hero {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--line);
}
.book-h1 {
  margin: 0 0 1rem;
  font-size: clamp(1.7rem, 3.2vw, 2.3rem);
  line-height: 1.2;
  font-weight: 850;
  letter-spacing: -0.01em;
  color: var(--ink);
}

/* 章节 */
.book-section {
  margin: 2.6rem 0;
}
.book-section > h2 {
  position: relative;
  margin: 0 0 1.2rem;
  padding-left: 1rem;
  border-left: 4px solid var(--brand);
  font-size: clamp(1.4rem, 2.4vw, 1.7rem);
  font-weight: 750;
  line-height: 1.3;
  letter-spacing: -0.005em;
  color: var(--ink);
}
.book-subsection {
  margin: 1.4rem 0;
}
.book-subsection > h3 {
  margin: 2rem 0 .7rem;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--brand-strong);
  line-height: 1.4;
}

/* Callout */
.book-callout {
  position: relative;
  margin: 1.6rem 0;
  padding: 1rem 1.2rem;
  border-radius: .75rem;
  line-height: 1.8;
}
.book-callout.tip {
  background: linear-gradient(180deg, #f0fdfa 0%, #ecfeff 100%);
  border-left: 4px solid #14b8a6;
  color: #134e4a;
}
.book-callout.warn {
  background: linear-gradient(180deg, #fffbeb 0%, #fef3c7 100%);
  border-left: 4px solid #f59e0b;
  color: #78350f;
}
.book-callout p:first-child { margin-top: 0; }
.book-callout p:last-child { margin-bottom: 0; }

/* 经典语录 */
.book-quote {
  position: relative;
  margin: 1.6rem 0;
  padding: 1rem 1.4rem;
  border-left: 4px solid var(--brand);
  border-radius: .5rem;
  background: linear-gradient(180deg, #faf8ff 0%, #f6f3ff 100%);
  color: #4c1d95;
  font-family: ui-serif, Georgia, "Songti SC", "Noto Serif SC", serif;
  font-size: 1.02rem;
  font-weight: 600;
  line-height: 1.85;
}
.book-quote::before {
  content: "“";
  position: absolute;
  top: -.1rem;
  left: .65rem;
  color: #c4b5fd;
  font-size: 2.4rem;
  font-weight: 900;
  line-height: 1;
  font-family: Georgia, "Times New Roman", serif;
}
.book-quote p { margin: .35rem 0; }

/* 有序列表（章末罗列） */
.book-list-decimal {
  margin: 1.5rem 0;
  padding-left: 1.6rem;
  color: #475569;
  line-height: 1.9;
}
.book-list-decimal > li {
  margin: .5rem 0;
}

/* 脚注 */
.book-footnote-list {
  margin: 2.5rem 0 1rem;
  padding-top: 1.2rem;
  border-top: 1px dashed var(--line);
  font-size: .9rem;
  color: var(--muted);
  line-height: 1.6;
  list-style: none;
  counter-reset: fn-counter;
}
.book-footnote-list > li {
  position: relative;
  margin: .35rem 0;
  padding-left: 1.6rem;
}
.book-footnote-list > li::before {
  counter-increment: fn-counter;
  content: "[" counter(fn-counter) "]";
  position: absolute;
  left: 0;
  color: var(--brand);
  font-weight: 700;
}
.book-fn-back {
  margin-left: .4rem;
  color: var(--brand-strong);
  text-decoration: none;
  font-weight: 700;
}
.book-fn-back:hover { color: var(--brand); }

/* 章末 meta */
.book-chapter-meta {
  margin-top: 2.5rem;
}
.book-meta-date {
  margin: 1rem 0;
  color: var(--muted);
  font-size: .9rem;
  font-style: italic;
}

/* 带 caption 的图 */
.book-figure.caption {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.book-figure.caption figcaption {
  margin-top: .65rem;
  color: var(--muted);
  font-size: .9rem;
  font-style: italic;
  text-align: center;
}

/* 章首 reflection 长段（ch01 那种 10 段第一人称铺陈） */
.book-aside.reflection {
  margin: 1.5rem 0;
  padding: 1.4rem 1.6rem;
  background: linear-gradient(180deg, #fbfaff 0%, #f6f3ff 100%);
  border-radius: .75rem;
  border: 1px solid #ede9fe;
}

/* 文字密度微调 */
.book-body { font-size: 1.0625rem; line-height: 2.0; }
.book-body p { margin: .85rem 0; }

/* === KRen Reading Spec v4 (2026-07-06) ===
   目标：整本书按长文阅读模板统一，降低章节标题、正文标题、引文和图片的视觉重量。 */

.book-layout {
  max-width: 78rem;
  gap: 2rem;
}

.book-article {
  max-width: 46rem;
}

.book-layout-index .book-article {
  max-width: 68rem;
}

.book-chapter-hero {
  margin-bottom: 1.25rem;
  padding-bottom: .85rem;
  border-bottom: 1px solid #edf0f5;
}

.book-h1,
.book-body h1 {
  margin: 0 0 .7rem;
  color: var(--ink);
  font-size: clamp(1.42rem, 2.05vw, 1.82rem);
  line-height: 1.34;
  font-weight: 820;
  letter-spacing: 0;
}

.book-byline-inline {
  display: block;
  max-width: 42rem;
  margin: .15rem 0 0;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  color: #64748b;
  font-size: .84rem;
  font-style: normal;
  font-weight: 500;
  line-height: 1.7;
  box-shadow: none;
}

.book-body {
  color: #334155;
  font-size: 1rem;
  line-height: 1.88;
}

.book-body p {
  margin: .72rem 0;
}

.book-section {
  margin: 1.85rem 0;
}

.book-section > h2,
.book-body h2 {
  margin: 1.75rem 0 .65rem;
  padding-left: .65rem;
  border-left: 3px solid var(--brand);
  color: #1f2937;
  font-size: clamp(1.06rem, 1.5vw, 1.24rem);
  font-weight: 760;
  line-height: 1.45;
  letter-spacing: 0;
}

.book-section:first-child > h2:first-child {
  margin-top: .25rem;
}

.book-subsection {
  margin: .9rem 0;
}

.book-subsection > h3,
.book-body h3 {
  margin: 1.15rem 0 .4rem;
  color: #334155;
  font-size: 1rem;
  font-weight: 720;
  line-height: 1.45;
  letter-spacing: 0;
}

.book-body ul,
.book-body ol,
.book-list-decimal {
  margin: .9rem 0;
}

.book-body ul > li,
.book-body ol > li,
.book-list-decimal > li {
  margin: .36rem 0;
  line-height: 1.78;
}

.book-body blockquote,
.book-quote {
  position: relative;
  margin: .95rem 0;
  padding: .72rem .95rem .72rem 1rem;
  border: 1px solid #ede9fe;
  border-left: 3px solid #8b5cf6;
  border-radius: .55rem;
  background: #fbfaff;
  color: #4c1d95;
  box-shadow: none;
  font-family: ui-serif, "Songti SC", "Noto Serif SC", Georgia, serif;
  font-size: .98rem;
  font-weight: 560;
  line-height: 1.72;
  letter-spacing: 0;
}

.book-body blockquote::before,
.book-quote::before {
  display: none;
}

.book-body blockquote p,
.book-quote p {
  margin: .18rem 0;
}

.book-quote + .book-quote {
  margin-top: .55rem;
}

.book-callout {
  margin: 1rem 0;
  padding: .8rem 1rem;
  border-radius: .55rem;
  line-height: 1.72;
}

.book-body .book-figure {
  margin: 1.15rem auto;
}

.book-body .book-figure img {
  width: auto;
  max-width: min(100%, 34rem);
  max-height: 52vh;
  border-radius: .6rem;
  box-shadow: 0 14px 34px -28px rgba(15, 23, 42, .35);
}

.book-figure.caption figcaption {
  margin-top: .45rem;
  font-size: .82rem;
  line-height: 1.5;
}

.book-cover {
  margin-bottom: 1.15rem;
  padding: 1.35rem 1.5rem;
  border-radius: .85rem;
}

.book-cover h1 {
  font-size: clamp(1.35rem, 2vw, 1.72rem);
  letter-spacing: 0;
}

.book-cover p {
  font-size: .96rem;
  line-height: 1.65;
}

.book-meta {
  margin: 1rem 0 1.25rem;
  padding: .9rem 1rem;
  border-radius: .65rem;
}

.book-parts-grid {
  gap: .75rem;
  margin: 1.1rem 0;
}

.book-part-card {
  padding: 1rem 1.1rem;
  border-radius: .65rem;
}

.book-part-card h3 {
  font-size: 1rem;
}

.book-pager {
  margin-top: 2.4rem;
  padding-top: 1.25rem;
}

.book-pager a {
  padding: .85rem .95rem;
  border-radius: .65rem;
}

@media (max-width: 960px) {
  .book-layout {
    gap: 0;
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .book-article,
  .book-layout-index .book-article {
    max-width: 100%;
  }
}

@media (max-width: 640px) {
  .book-layout {
    padding-top: 4.4rem;
    padding-bottom: 2.8rem;
  }

  .book-h1,
  .book-body h1 {
    font-size: 1.34rem;
  }

  .book-byline-inline {
    font-size: .8rem;
    line-height: 1.65;
  }

  .book-body {
    font-size: .98rem;
    line-height: 1.82;
  }

  .book-section > h2,
  .book-body h2 {
    font-size: 1.06rem;
  }

  .book-body blockquote,
  .book-quote {
    margin: .8rem 0;
    padding: .65rem .78rem .65rem .85rem;
    font-size: .95rem;
  }

  .book-body .book-figure {
    margin: 1rem auto;
  }

  .book-body .book-figure img {
    width: 100%;
    max-width: 100%;
    max-height: none;
  }
}

/* === KRen Reading Spec v4.1 (2026-07-06) ===
   内容修复：章首标语完整保留；首页恢复左目录 + 右正文；图片说明进入 figcaption。 */

.book-byline-inline {
  max-width: 46rem;
  color: #64748b;
  font-size: .86rem;
  line-height: 1.7;
}

.book-index-shell {
  display: grid;
  grid-template-columns: minmax(18rem, 24rem) minmax(0, 1fr);
  gap: 2rem;
  align-items: start;
}

.book-index-rail {
  position: sticky;
  top: 5.25rem;
}

.book-index-content {
  max-width: 46rem;
  padding: .25rem 0 0;
}

.book-index-content h2:first-child {
  margin-top: .2rem;
}

.book-index-content h3 {
  margin: 1.1rem 0 .45rem;
  color: #334155;
  font-size: 1rem;
  line-height: 1.45;
  font-weight: 740;
}

.book-index-list {
  margin: .55rem 0 1rem;
  padding-left: 1.35rem;
  color: #475569;
  line-height: 1.78;
}

.book-index-list > li {
  margin: .28rem 0;
}

.book-figure.caption figcaption,
.book-body .book-figure figcaption {
  max-width: min(100%, 34rem);
  margin: .48rem auto 0;
  color: #64748b;
  font-size: .82rem;
  line-height: 1.5;
  text-align: center;
}

@media (max-width: 960px) {
  .book-index-shell {
    grid-template-columns: 1fr;
    gap: 1.4rem;
  }

  .book-index-rail {
    position: static;
  }

  .book-index-content {
    max-width: 100%;
  }
}

@media (max-width: 640px) {
  .book-byline-inline {
    font-size: .8rem;
    line-height: 1.62;
  }
}

/* === KRen Reading UI v4.2 (2026-07-06) ===
   审查优化：弱化 SaaS 卡片感，强化长文阅读节奏、侧栏定位与首页目录扫描。 */

body {
  background:
    radial-gradient(circle at 50% -12rem, rgba(131, 76, 214, .08), transparent 28rem),
    linear-gradient(180deg, #fbfaf7 0%, #ffffff 24rem);
}

.book-layout {
  max-width: 80rem;
  grid-template-columns: 17rem minmax(0, 1fr);
  gap: 3rem;
  padding-top: 5.4rem;
}

.book-main {
  display: flex;
  justify-content: center;
}

.book-article {
  width: 100%;
  max-width: 49rem;
}

.book-layout-index .book-article {
  max-width: 72rem;
}

.book-sidebar {
  padding: .25rem .5rem 1rem 0;
}

.book-sidebar-title {
  margin-bottom: .85rem;
  padding: .15rem 0 .7rem;
  color: #111827;
  font-size: .98rem;
  line-height: 1.45;
  letter-spacing: .01em;
}

.book-toc {
  font-size: .84rem;
}

.book-toc .toc-part {
  margin: 1rem 0 .28rem;
  color: #6d28d9;
  font-size: .68rem;
  letter-spacing: .055em;
}

.book-toc a {
  display: grid;
  grid-template-columns: 1.7rem minmax(0, 1fr);
  gap: .25rem;
  padding: .34rem .55rem;
  color: #475569;
  border-radius: .5rem;
}

.book-toc a:hover {
  background: rgba(237, 233, 254, .72);
}

.book-toc a.is-current {
  position: relative;
  background: #f3f0ff;
  color: #4c1d95;
  font-weight: 760;
}

.book-toc a.is-current::before {
  content: "";
  position: absolute;
  inset: .42rem auto .42rem .08rem;
  width: 3px;
  border-radius: 999px;
  background: #7c3aed;
}

.book-toc .toc-num {
  margin: 0;
  color: #94a3b8;
  font-variant-numeric: tabular-nums;
}

.book-breadcrumb {
  margin-bottom: 1.15rem;
  color: #7c3aed;
  font-size: .78rem;
}

.book-chapter-hero {
  margin-bottom: 1.55rem;
  padding-bottom: 1.15rem;
  border-bottom: 1px solid #e6e9ef;
}

.book-h1,
.book-body h1 {
  max-width: 44rem;
  font-size: clamp(1.58rem, 2.35vw, 2.05rem);
  line-height: 1.32;
  font-weight: 840;
  letter-spacing: -.01em;
}

.book-byline-inline {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem .55rem;
  max-width: 44rem;
  margin-top: .35rem;
  color: #64748b;
  font-size: .82rem;
  line-height: 1.55;
}

.book-byline-inline span {
  display: inline-flex;
  align-items: center;
}

.book-byline-inline span:not(:last-child)::after {
  content: "";
  width: .22rem;
  height: .22rem;
  margin-left: .55rem;
  border-radius: 999px;
  background: #c4b5fd;
}

.book-body {
  color: #2f3a4a;
  font-size: 1.045rem;
  line-height: 2.02;
  text-rendering: optimizeLegibility;
}

.book-body p {
  margin: .82rem 0;
}

.book-section {
  margin: 2.25rem 0;
}

.book-section > h2,
.book-body h2 {
  margin: 2.15rem 0 .78rem;
  padding: 0 0 .38rem;
  border-left: 0;
  border-bottom: 1px solid #edf0f5;
  color: #111827;
  font-size: clamp(1.16rem, 1.65vw, 1.38rem);
  font-weight: 780;
  line-height: 1.42;
}

.book-subsection > h3,
.book-body h3 {
  margin: 1.3rem 0 .42rem;
  color: #334155;
  font-size: 1.02rem;
  font-weight: 760;
}

.book-body blockquote,
.book-quote {
  margin: 1.2rem 0;
  padding: .82rem 1rem .86rem 1.15rem;
  border: 1px solid #e9d5ff;
  border-left: 3px solid #7c3aed;
  border-radius: .65rem;
  background: #fdfbff;
  color: #4c1d95;
  font-size: 1rem;
  line-height: 1.82;
}

.book-callout {
  border-radius: .65rem;
}

.book-body .book-figure {
  margin: 1.45rem auto;
}

.book-body .book-figure img {
  max-width: min(100%, 38rem);
  max-height: 58vh;
  border-radius: .7rem;
  box-shadow: 0 18px 42px -30px rgba(15, 23, 42, .35);
}

.book-chapter-meta {
  margin-top: 2.8rem;
}

.book-pager {
  gap: .85rem;
  margin-top: 2.8rem;
}

.book-pager a {
  background: #fff;
  border-color: #e5e7eb;
}

.book-pager a:hover {
  border-color: #c4b5fd;
  background: #fbfaff;
}

.book-index-shell {
  grid-template-columns: minmax(17rem, 22rem) minmax(0, 1fr);
  gap: 3rem;
}

.book-cover {
  padding: 1.45rem 1.55rem;
  color: #111827;
  border: 1px solid #e9d5ff;
  border-radius: .95rem;
  background:
    linear-gradient(135deg, rgba(124, 58, 237, .10), transparent 42%),
    #fff;
  box-shadow: 0 18px 46px -38px rgba(91, 33, 182, .48);
}

.book-cover h1 {
  color: #111827;
  font-size: clamp(1.42rem, 2.1vw, 1.86rem);
  font-weight: 900;
}

.book-cover p {
  color: #475569;
}

.book-cover .book-cover-meta {
  gap: .42rem;
  margin-top: .85rem;
}

.book-cover .book-cover-meta span {
  background: #f3f0ff;
  color: #5b21b6;
  font-weight: 720;
}

.book-meta {
  background: rgba(255, 255, 255, .78);
}

.book-part-card {
  border-color: #e7e5ee;
  background: rgba(255, 255, 255, .9);
  box-shadow: 0 12px 30px -28px rgba(15, 23, 42, .28);
}

.book-part-card .part-chapters {
  gap: .45rem;
}

.book-part-card .part-chapters a {
  background: #f7f5ff;
  color: #5b21b6;
  line-height: 1.45;
}

.book-index-content {
  max-width: 49rem;
}

.book-index-content h2,
.book-index-content h3 {
  scroll-margin-top: 5rem;
}

.book-index-list {
  padding-left: 1.15rem;
}

.book-sidebar-toggle {
  min-height: 2.75rem;
  padding: .65rem 1.05rem;
}

@media (max-width: 960px) {
  .book-layout {
    grid-template-columns: 1fr;
    max-width: 56rem;
    gap: 0;
  }

  .book-main {
    display: block;
  }

  .book-sidebar {
    padding: 5rem 1rem 2rem;
  }

  .book-index-shell {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}

@media (max-width: 640px) {
  .book-layout {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .book-h1,
  .book-body h1 {
    font-size: 1.42rem;
  }

  .book-byline-inline {
    display: block;
    font-size: .82rem;
  }

  .book-byline-inline span {
    display: block;
  }

  .book-byline-inline span:not(:last-child)::after {
    display: none;
  }

  .book-body {
    font-size: 1rem;
    line-height: 1.9;
  }

  .book-section > h2,
  .book-body h2 {
    font-size: 1.12rem;
  }

  .book-cover {
    padding: 1.25rem;
  }
}

/* === KRen Agent-Book Alignment v4.3 (2026-07-06) ===
   参考 Harness-Agent-Book：统一书籍栅格、导航节奏、章节标题层级与首页封面。 */

body {
  background: linear-gradient(180deg, #fbfbff 0%, #ffffff 26rem), #ffffff;
}

.book-layout {
  max-width: 84rem;
  grid-template-columns: 18rem minmax(0, 1fr);
  gap: 2.5rem;
  padding: 5rem 1.25rem 4rem;
}

.book-main {
  display: block;
  min-width: 0;
}

.book-article {
  max-width: 54rem;
}

.book-layout-index .book-article {
  max-width: 72rem;
}

.book-sidebar {
  top: 5rem;
  max-height: calc(100vh - 6rem);
  padding-right: .5rem;
}

.book-sidebar-title {
  margin-bottom: 1rem;
  padding-bottom: .75rem;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: 0;
}

.book-toc {
  font-size: .875rem;
}

.book-toc .toc-part {
  margin: 1.1rem 0 .35rem;
  color: var(--brand-strong);
  font-size: .72rem;
  font-weight: 900;
  letter-spacing: .04em;
}

.book-toc a {
  display: block;
  padding: .34rem .6rem;
  color: #475569;
  border-radius: .5rem;
  line-height: 1.5;
}

.book-toc a:hover {
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.book-toc a.is-current {
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-weight: 700;
}

.book-toc a.is-current::before {
  display: none;
}

.book-toc .toc-num {
  color: var(--muted);
  font-weight: 700;
  margin-right: .3rem;
}

.book-toc a.is-current .toc-num {
  color: var(--brand);
}

.book-breadcrumb {
  margin-bottom: 1.5rem;
  color: var(--brand-strong);
  font-size: .82rem;
  font-weight: 800;
}

.book-chapter-hero {
  margin-bottom: 1.65rem;
  padding-bottom: 1.15rem;
  border-bottom: 1px solid var(--line);
}

.book-h1,
.book-body h1 {
  max-width: none;
  margin: 0 0 .8rem;
  color: var(--ink);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.book-byline-inline {
  display: block;
  max-width: 48rem;
  margin: 0;
  color: var(--muted);
  font-size: .86rem;
  line-height: 1.65;
}

.book-byline-inline span {
  display: block;
}

.book-byline-inline span:not(:last-child)::after {
  display: none;
}

.book-body {
  color: #374151;
  font-size: 1.05rem;
  line-height: 1.95;
}

.book-body p {
  margin: 1.05rem 0;
}

.book-section {
  margin: 2.4rem 0;
}

.book-section > h2,
.book-body h2 {
  margin: 2.4rem 0 .9rem;
  padding: 0;
  border: 0;
  color: var(--ink);
  font-size: clamp(1.25rem, 2vw, 1.5rem);
  line-height: 1.3;
  font-weight: 750;
  letter-spacing: -0.005em;
}

.book-section:first-child > h2:first-child {
  margin-top: 0;
}

.book-subsection > h3,
.book-body h3 {
  margin: 1.6rem 0 .6rem;
  color: var(--ink);
  font-size: 1.05rem;
  line-height: 1.4;
  font-weight: 700;
}

.book-body ul,
.book-body ol,
.book-list-decimal {
  margin: 1.25rem 0;
}

.book-body ul > li,
.book-body ol > li,
.book-list-decimal > li {
  margin: .6rem 0;
  line-height: 1.85;
}

.book-body blockquote,
.book-quote {
  margin: 1.75rem 0;
  padding: 1.05rem 1.3rem;
  border: 1px solid #ece9fe;
  border-left: 4px solid var(--brand);
  border-radius: .875rem;
  background: linear-gradient(180deg, #faf8ff 0%, #f6f3ff 100%);
  color: #4c1d95;
  font-size: 1.02rem;
  font-weight: 600;
  line-height: 1.8;
}

.book-callout {
  margin: 1.5rem 0;
  padding: 1rem 1.2rem;
  border-radius: .75rem;
}

.book-body .book-figure {
  margin: 1.8rem auto;
}

.book-body .book-figure img {
  max-width: min(100%, 42rem);
  max-height: calc(100vh - 8rem);
  border-radius: .875rem;
  box-shadow: 0 22px 52px -38px rgba(15, 23, 42, .4);
}

.book-pager {
  margin-top: 3.5rem;
  padding-top: 1.75rem;
}

.book-pager a {
  padding: 1rem 1.15rem;
  border-radius: .875rem;
}

.book-layout-index {
  /* 首页与章节页共用标准双栏布局 */
}

.book-index-shell {
  grid-template-columns: minmax(18rem, 24rem) minmax(0, 1fr);
  gap: 2.5rem;
}

.book-cover.hero-grad {
  margin-bottom: 1.5rem;
  padding: 1.6rem 1.8rem;
  color: #fff;
  border: 0;
  border-radius: 1.25rem;
  background: linear-gradient(283.01deg, #834CD6 8.03%, #9546E2 34.85%, #B935D9 100%);
  box-shadow: 0 26px 70px -42px rgba(109, 40, 217, .9);
}

.book-cover.hero-grad h1 {
  color: #fff;
  font-size: clamp(1.45rem, 2.4vw, 1.85rem);
  line-height: 1.2;
  font-weight: 850;
}

.book-cover.hero-grad p {
  color: rgba(255, 255, 255, .88);
}

.book-cover.hero-grad .book-cover-meta span {
  background: rgba(255, 255, 255, .15);
  color: rgba(255, 255, 255, .95);
  font-size: .78rem;
  font-weight: 600;
}

.book-part-card {
  padding: 1.25rem 1.4rem;
  border: 1px solid var(--line);
  border-radius: 1rem;
  background: #fff;
  box-shadow: none;
}

.book-part-card h3 {
  font-size: 1.05rem;
  font-weight: 900;
}

.book-part-card .part-chapters a {
  padding: .25rem .6rem;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-size: .8rem;
  font-weight: 600;
}

.book-index-content {
  max-width: 54rem;
}

@media (max-width: 960px) {
  .book-layout {
    grid-template-columns: 1fr;
    max-width: 84rem;
    padding-top: 4.5rem;
  }

  .book-sidebar {
    padding: 5rem 1rem 2rem;
  }

  .book-index-shell {
    grid-template-columns: 1fr;
    gap: 1.4rem;
  }
}

@media (max-width: 640px) {
  .book-body {
    font-size: 1rem;
    line-height: 1.88;
  }

  .book-h1,
  .book-body h1 {
    font-size: 1.46rem;
  }

  .book-byline-inline {
    display: block;
    font-size: .82rem;
    line-height: 1.62;
  }

  .book-body .book-figure img {
    max-width: 100%;
    max-height: none;
  }
}

/* === KRen Index & Preface polish v4.4 (2026-07-06) === */

.book-index-page .book-cover.hero-grad {
  margin-bottom: 1.75rem;
}

.book-pitch {
  margin: .85rem 0 0;
  max-width: 38rem;
}

.book-pitch p {
  margin: 0;
  color: rgba(255, 255, 255, .92);
  font-size: clamp(.95rem, 1.6vw, 1.05rem);
  line-height: 1.72;
  letter-spacing: .01em;
}

.book-index-meta {
  margin-bottom: 1.5rem;
}

.book-index-intro {
  display: grid;
  gap: .35rem;
}

.book-index-intro .book-section-heading {
  margin-top: 1.75rem;
}

.book-index-intro .book-section-heading:first-child {
  margin-top: 0;
}

.book-index-highlights {
  margin: .5rem 0 1rem;
  padding-left: 1.15rem;
  color: var(--ink);
}

.book-index-highlights li {
  margin: .45rem 0;
  line-height: 1.7;
}

.book-index-highlights strong {
  color: var(--brand-strong);
}

.book-section-heading {
  margin: 2rem 0 .35rem;
  font-size: 1.2rem;
  font-weight: 900;
  letter-spacing: -.01em;
}

.book-section-lead {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: .95rem;
  line-height: 1.65;
}

.book-index-page .book-parts-grid {
  margin-top: .25rem;
}

.book-part-card .part-theme {
  margin: 0 0 .75rem;
  color: var(--muted);
  font-size: .88rem;
  line-height: 1.55;
}

.book-index-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}

.book-index-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: .65rem 1.15rem;
  border: 1px solid var(--line);
  border-radius: .75rem;
  background: #fff;
  color: var(--ink);
  font-size: .92rem;
  font-weight: 700;
  text-decoration: none;
  transition: border-color .15s, box-shadow .15s, transform .15s;
}

.book-index-action:hover {
  border-color: #ddd6fe;
  box-shadow: 0 14px 34px -28px rgba(124, 58, 237, .75);
  color: var(--brand-strong);
}

.book-index-action.primary {
  border-color: transparent;
  background: linear-gradient(283.01deg, #834CD6 8.03%, #9546E2 34.85%, #B935D9 100%);
  color: #fff;
  box-shadow: 0 18px 42px -28px rgba(109, 40, 217, .85);
}

.book-index-action.primary:hover {
  color: #fff;
  transform: translateY(-1px);
}

.book-index-intro .book-quote {
  margin: .75rem 0 1rem;
  padding: 1rem 1.15rem;
  border-left: 3px solid var(--brand);
  border-radius: .75rem;
  background: var(--brand-soft);
}

.book-index-intro .book-quote p {
  margin: 0;
  color: #334155;
  line-height: 1.75;
}

@media (max-width: 640px) {
  .book-pitch p {
    font-size: .92rem;
    line-height: 1.65;
  }

  .book-index-actions {
    flex-direction: column;
  }

  .book-index-action {
    width: 100%;
  }
}

/* ---- 心法口诀专属样式 ---- */

/*
 * 字号层级设计（桌面端）
 *   H1 标题        : 2.0~2.3rem  （页面主标题，最大）
 *   口诀正文      : 1.625rem    （核心内容，醒目突出）
 *   章节标题 H2   : 1.25rem     （分区标题，中等偏小）
 *   小标题 H3     : 1.06rem     （段落内副标题）
 *   正文/注释放大 : .95~1rem     （基础正文）
 *   辅助文字      : .8~.9rem    （byline、badge、cite）
 */

/* 心法口诀页面：覆盖基础书籍样式的 H2 大小 */
.book-article[data-chapter] .book-section > h2,
.book-article[data-chapter] .book-body > section > h2 {
  font-size: 1.22rem;
  font-weight: 700;
  margin: 2rem 0 .7rem;
  padding-left: .6rem;
  border-left: 3px solid #834CD6;
  color: #1f2937;
}

/* 口诀编号标签 */
.mantra-badge {
  display: inline-block;
  padding: .25rem .75rem;
  margin-bottom: 1rem;
  font-size: .8rem;
  font-weight: 600;
  color: #834CD6;
  background: rgba(131, 76, 214, .08);
  border-radius: 1rem;
  border: 1px solid rgba(131, 76, 214, .18);
  letter-spacing: .03em;
}

/* 口诀卡片 */
.mantra-card {
  margin: 1.5rem 0;
  padding: 2rem;
  background: linear-gradient(135deg, #fbfbff 0%, #f5f0ff 100%);
  border-left: 4px solid #834CD6;
  border-radius: .5rem;
  box-shadow: 0 4px 12px -4px rgba(131, 76, 214, .15);
}

.mantra-card blockquote {
  margin: 0;
  padding: 0;
  border: none;
  background: none;
}

.mantra-text {
  font-size: 1.625rem;
  font-weight: 700;
  line-height: 1.85;
  color: #1a1a2e;
  font-family: "Songti SC", "Noto Serif SC", "STSong", serif;
}

.mantra-card cite {
  display: block;
  margin-top: 1rem;
  font-size: .85rem;
  color: #834CD6;
  font-style: normal;
  font-weight: 500;
  opacity: .8;
}

/* 注释网格 */
.annotation-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.annotation-item {
  padding: 1rem;
  background: #f8f8fc;
  border-radius: .5rem;
  border: 1px solid rgba(131, 76, 214, .08);
}

.annotation-item dt {
  font-size: .95rem;
  font-weight: 700;
  color: #834CD6;
  margin-bottom: .35rem;
}

.annotation-item dd {
  margin: 0;
  font-size: .9rem;
  line-height: 1.65;
  color: #4a4a6a;
}

/* 翻译框 */
.translation-box {
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem;
  background: #fffefb;
  border: 1px solid rgba(131, 76, 214, .12);
  border-radius: .5rem;
  box-shadow: 0 2px 8px -2px rgba(0, 0, 0, .04);
}

.translation-box p {
  margin: .6rem 0;
  line-height: 1.85;
  font-size: .95rem;
  color: #2a2a4a;
}

/* 解读内容 */
.interpretation-content {
  margin: 1.5rem 0;
  line-height: 1.9;
}

.interpretation-content h3 {
  margin: 1.5rem 0 .75rem;
  font-size: 1.06rem;
  font-weight: 700;
  color: #834CD6;
}

.interpretation-content blockquote {
  margin: 1.25rem 0;
  padding: .9rem 1.25rem;
  background: #fbfbff;
  border-left: 3px solid #834CD6;
  border-radius: .25rem;
  font-style: italic;
  color: #4a4a6a;
  font-size: .93rem;
  line-height: 1.7;
}

/* 实践要点框 */
.practice-box {
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem;
  background: linear-gradient(135deg, #f0fdf4 0%, #fbfbff 100%);
  border: 1px solid rgba(34, 197, 94, .18);
  border-radius: .5rem;
}

.practice-box h3 {
  margin: 0 0 .85rem;
  font-size: 1.06rem;
  font-weight: 700;
  color: #16a34a;
}

.practice-box ol {
  margin: 0;
  padding-left: 1.5rem;
}

.practice-box li {
  margin: .6rem 0;
  line-height: 1.8;
  font-size: .95rem;
}

.practice-tip {
  margin-top: 1.25rem;
  padding: .85rem 1rem;
  background: #fef9e7;
  border-left: 3px solid #f59e0b;
  border-radius: .25rem;
}

.practice-tip h4 {
  margin: 0 0 .4rem;
  font-size: .92rem;
  font-weight: 600;
  color: #92400e;
}

.practice-tip p {
  margin: 0;
  font-size: .875rem;
  color: #78350f;
  line-height: 1.65;
}

/* 案例研究 */
.case-study {
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem;
  background: #f8f8fc;
  border-radius: .5rem;
}

.case-study h3 {
  margin: 0 0 .85rem;
  font-size: 1.06rem;
  font-weight: 700;
  color: #834CD6;
}

.case-study p {
  margin: .6rem 0;
  line-height: 1.8;
  font-size: .95rem;
}

/* 响应式优化 */
@media (max-width: 768px) {
  .mantra-text {
    font-size: 1.375rem;
  }

  .annotation-grid {
    grid-template-columns: 1fr;
  }

  .mantra-card {
    padding: 1.25rem;
  }

  .mantra-badge {
    font-size: .75rem;
  }
}

/* === KRen Mindset Book v5 (2026-07-06) ===
   统一心法口诀版式：修复多层 CSS 冲突、首页装帧、侧栏交互、口诀卡片阅读密度。 */

/* 侧栏滚动与当前项 */
.book-sidebar {
  scrollbar-width: thin;
  scrollbar-color: #c4b5fd transparent;
}
.book-sidebar::-webkit-scrollbar { width: 6px; }
.book-sidebar::-webkit-scrollbar-thumb {
  background: #ddd6fe;
  border-radius: 999px;
}

.book-toc a {
  display: grid;
  grid-template-columns: 1.7rem minmax(0, 1fr);
  gap: .25rem;
  align-items: start;
}

.book-toc a.is-current {
  position: relative;
  background: #f3f0ff;
  color: #4c1d95;
  font-weight: 760;
}

.book-toc a.is-current::before {
  content: "";
  position: absolute;
  inset: .42rem auto .42rem .08rem;
  width: 3px;
  border-radius: 999px;
  background: #7c3aed;
}

.book-toc .toc-num {
  margin: 0;
  color: #94a3b8;
  font-variant-numeric: tabular-nums;
}

.book-toc a.is-current .toc-num { color: #7c3aed; }

/* 移动端侧栏遮罩 */
@media (max-width: 960px) {
  body.book-sidebar-open::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: 54;
    background: rgba(15, 23, 42, .35);
    backdrop-filter: blur(2px);
  }
}

/* 阅读区统一（覆盖 v3–v4.4 冲突） */
.book-layout {
  max-width: 78rem;
  gap: 2rem;
}

.book-article {
  max-width: 46rem;
}

.book-layout-index .book-article,
.book-index-page {
  max-width: 68rem;
}

.book-chapter-hero {
  margin-bottom: 1.35rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid #e6e9ef;
}

.book-h1,
.book-body h1 {
  margin: 0 0 .65rem;
  font-size: clamp(1.5rem, 2.2vw, 1.95rem);
  line-height: 1.32;
  font-weight: 820;
  letter-spacing: -.01em;
  color: var(--ink);
}

.book-byline-inline {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem .55rem;
  max-width: 44rem;
  margin-top: .2rem;
  color: #64748b;
  font-size: .82rem;
  line-height: 1.55;
}

.book-byline-inline span {
  display: inline-flex;
  align-items: center;
}

.book-byline-inline span:not(:last-child)::after {
  content: "";
  width: .22rem;
  height: .22rem;
  margin-left: .55rem;
  border-radius: 999px;
  background: #c4b5fd;
}

.book-body {
  color: #2f3a4a;
  font-size: 1.02rem;
  line-height: 1.92;
}

.book-body p { margin: .78rem 0; }

.book-article[data-chapter] .book-section > h2,
.book-article[data-chapter] .book-body > section > h2 {
  margin: 1.85rem 0 .65rem;
  padding: 0 0 .35rem;
  border-left: 0;
  border-bottom: 1px solid #edf0f5;
  font-size: 1.12rem;
  font-weight: 760;
  line-height: 1.42;
  color: #111827;
}

.book-article[data-chapter] .book-section:first-child > h2:first-child {
  margin-top: .15rem;
}

/* 口诀组件：降低视觉重量，突出可读性 */
.mantra-badge {
  margin-bottom: .65rem;
  padding: .2rem .65rem;
  font-size: .76rem;
  letter-spacing: .04em;
}

.mantra-card {
  margin: 1rem 0 1.25rem;
  padding: 1.35rem 1.45rem;
  background: linear-gradient(180deg, #fbfaff 0%, #f6f3ff 100%);
  border: 1px solid #ece9fe;
  border-left: 3px solid #834CD6;
  border-radius: .65rem;
  box-shadow: none;
}

.mantra-card blockquote {
  margin: 0;
  padding: 0;
  border: none;
  background: none;
  box-shadow: none;
}

.mantra-card blockquote::before { display: none; }

.mantra-text {
  font-size: clamp(1.15rem, 1.8vw, 1.38rem);
  font-weight: 650;
  line-height: 1.75;
  color: #1a1a2e;
}

.mantra-card cite {
  margin-top: .75rem;
  font-size: .8rem;
}

.annotation-grid {
  gap: .75rem;
  margin: 1rem 0 1.25rem;
}

.annotation-item {
  padding: .85rem .95rem;
}

.translation-box,
.practice-box,
.case-study {
  margin: 1rem 0 1.25rem;
  padding: 1rem 1.15rem;
}

.interpretation-content h3 {
  margin: 1.15rem 0 .55rem;
  font-size: 1rem;
  color: #5b21b6;
}

.practice-tip {
  margin-top: 1rem;
  padding: .75rem .9rem;
}

/* 前言页（沿用章内排版） */
.book-article-header {
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid #e6e9ef;
}

.book-article-title {
  margin: 0 0 .5rem;
  font-size: clamp(1.5rem, 2.2vw, 1.95rem);
  line-height: 1.3;
  font-weight: 820;
  color: var(--ink);
}

.book-article-subtitle {
  margin: 0 0 .65rem;
  color: #64748b;
  font-size: .92rem;
  line-height: 1.6;
}

.book-article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem .55rem;
  color: #64748b;
  font-size: .82rem;
}

.book-article-meta span {
  display: inline-flex;
  align-items: center;
}

.book-article-meta span:not(:last-child)::after {
  content: "";
  width: .22rem;
  height: .22rem;
  margin-left: .55rem;
  border-radius: 999px;
  background: #c4b5fd;
}

.book-article-body h2 {
  margin: 1.85rem 0 .65rem;
  padding-bottom: .35rem;
  border-bottom: 1px solid #edf0f5;
  font-size: 1.12rem;
  font-weight: 760;
  color: #111827;
}

.book-article-body p,
.book-article-body li {
  line-height: 1.88;
  color: #334155;
}

/* 墨黑朱砂封面（与 KRen-two-book 对齐） */
.kr-cover {
  position: relative;
  margin-bottom: 1.5rem;
  padding: 2.2rem 2.4rem 2rem;
  border: 0;
  border-radius: 1.25rem;
  color: #E8DFD0;
  overflow: hidden;
  background: radial-gradient(120% 90% at 28% 18%, #2A2620 0%, #1C1A17 55%, #100F0D 100%);
  box-shadow: 0 30px 80px -48px rgba(0, 0, 0, .85);
}

.kr-cover-grain {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .5;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.91 0 0 0 0 0.87 0 0 0 0 0.81 0 0 0 0.08 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
}

.kr-cover::after {
  content: "";
  position: absolute;
  inset: 14px;
  border: 1px solid rgba(232, 223, 208, .10);
  border-radius: .9rem;
  pointer-events: none;
  z-index: 4;
}

.kr-cover-inner { position: relative; z-index: 5; }

.kr-cover-mark {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.1rem;
}

.kr-cover-mark .kr-series {
  font-size: .78rem;
  font-weight: 400;
  letter-spacing: .18em;
  color: #B8AE9C;
}

.kr-cover-mark .kr-series b {
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-weight: 500;
  color: #E8DFD0;
  letter-spacing: .12em;
}

.kr-cover-mark .kr-series .kr-vol {
  font-style: italic;
  color: #B8392B;
  font-family: "Cormorant Garamond", Georgia, serif;
  font-size: .85rem;
  letter-spacing: .08em;
  margin-left: .3em;
}

.kr-cover-mark .kr-seal-mini {
  width: 1.5rem;
  height: 1.5rem;
  border: 1px solid #B8392B;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #B8392B;
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-size: .78rem;
  font-weight: 700;
}

.kr-title {
  margin: 0 0 .9rem;
  font-family: "Noto Serif SC", "Songti SC", "STSong", serif;
  font-weight: 900;
  font-size: clamp(2.2rem, 5.5vw, 3.4rem);
  line-height: 1.1;
  letter-spacing: .04em;
  color: #E8DFD0;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .06em;
}

.kr-title .kr-ch { display: inline-block; }

.kr-title .kr-ch-acc {
  color: #B8392B;
  position: relative;
}

.kr-title .kr-ch-acc::after {
  content: "";
  position: absolute;
  inset: -3px;
  border: 2px solid #B8392B;
  opacity: .35;
}

.kr-subtitle {
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-weight: 400;
  font-size: clamp(.9rem, 1.6vw, 1.05rem);
  letter-spacing: .14em;
  color: #B8AE9C;
  margin-bottom: 1.1rem;
}

.kr-accent-line {
  width: 3.2rem;
  height: 2px;
  background: #B8392B;
  margin-bottom: 1.1rem;
}

.kr-pitch { margin: 0 0 1.1rem; }

.kr-pitch p {
  margin: 0;
  color: #B8AE9C;
  font-size: .98rem;
  line-height: 1.85;
}

.kr-meta {
  margin-top: 0;
  display: flex;
  flex-wrap: wrap;
  gap: .42rem;
  margin-bottom: 1.1rem;
}

.kr-meta span {
  padding: .22rem .62rem;
  border-radius: 999px;
  background: rgba(232, 223, 208, .10);
  border: 1px solid rgba(232, 223, 208, .16);
  color: #E8DFD0;
  font-size: .76rem;
  font-weight: 600;
  letter-spacing: .04em;
}

.kr-tagline {
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-weight: 400;
  font-size: .82rem;
  letter-spacing: .18em;
  color: #B8AE9C;
  line-height: 1.8;
  padding-top: .8rem;
  border-top: 1px solid rgba(232, 223, 208, .10);
}

.kr-tagline i {
  color: #B8392B;
  font-style: normal;
  margin: 0 .35em;
}

/* 第 40 条终章（从 ch40 内联样式提取） */
.book-chapter-hero.final-chapter {
  padding: 1.5rem;
  border-radius: .75rem;
  background: linear-gradient(135deg, rgba(131, 76, 214, .08), rgba(255, 215, 0, .06));
  border: 1px solid rgba(131, 76, 214, .15);
  border-bottom: 1px solid rgba(131, 76, 214, .15);
}

.final-chapter .mantra-badge {
  background: rgba(255, 215, 0, .15);
  border-color: rgba(255, 215, 0, .3);
  color: #92400e;
}

.mantra-card.wangyangming-quote {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  border-left-color: #ffd700;
  border-color: rgba(255, 215, 0, .2);
}

.mantra-text.final {
  color: #ffd700;
  font-size: clamp(1.35rem, 2vw, 1.75rem);
  text-align: center;
}

.wangyangming-quote cite {
  color: rgba(255, 215, 0, .7);
  text-align: center;
}

.book-end.final {
  background: linear-gradient(135deg, rgba(255, 215, 0, .1), rgba(131, 76, 214, .1));
  padding: 2rem;
  border-radius: .75rem;
  border: 1px solid rgba(255, 215, 0, .2);
  text-align: center;
  margin-top: 3rem;
}

@media (max-width: 640px) {
  .book-h1,
  .book-body h1 {
    font-size: 1.38rem;
  }

  .book-byline-inline {
    font-size: .78rem;
  }

  .mantra-text {
    font-size: 1.12rem;
  }

  .mantra-card {
    padding: 1rem 1.05rem;
  }

  .kr-cover {
    padding: 1.6rem 1.4rem 1.4rem;
  }

  .kr-cover::after { inset: 9px; }

  .kr-title {
    font-size: clamp(2rem, 9vw, 2.8rem);
  }

  .kr-pitch p {
    font-size: .9rem;
    line-height: 1.7;
  }

  .kr-tagline {
    font-size: .74rem;
    letter-spacing: .12em;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .book-sidebar { transition: none; }
}

/* 书籍页脚（替代无 CSS 定义的 site-footer/footer-grid） */
.book-site-footer {
  max-width: 78rem;
  margin: 2.5rem auto 0;
  padding: 1.5rem 1.25rem 2.75rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .6rem 1.25rem;
  color: #94a3b8;
  font-size: .82rem;
  line-height: 1.6;
}

.book-site-footer p { margin: 0; }

.book-site-footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem 1.15rem;
}

.book-site-footer-links a { color: #64748b; }
.book-site-footer-links a:hover { color: var(--brand-strong); }

@media (max-width: 640px) {
  .book-site-footer {
    flex-direction: column;
    align-items: flex-start;
    padding: 1.25rem 1rem 2rem;
  }
}

/* v6 — 口诀原文：完整问答段落 + 口诀高亮 */
.original-passage {
  margin: 1.25rem 0 0;
  padding: 1.35rem 1.45rem;
  background: linear-gradient(180deg, #fdf8f0 0%, #faf5eb 100%);
  border: 1px solid #e8dcc8;
  border-radius: .65rem;
  box-shadow: 0 1px 0 rgba(255,255,255,.6) inset;
}

.original-passage.final {
  background: linear-gradient(180deg, #f8f4ec 0%, #f3ede3 100%);
  border-color: #d4c4a8;
}

.original-text {
  margin: 0 0 .85rem;
  font-family: "Noto Serif SC", "Songti SC", "STSong", serif;
  font-size: 1.02rem;
  line-height: 1.95;
  color: #3d3429;
  text-align: justify;
}

.original-text:last-child { margin-bottom: 0; }

.mantra-highlight {
  color: #b91c1c;
  font-weight: 700;
  letter-spacing: .02em;
}

.original-cite {
  margin: .75rem 0 0;
  font-size: .88rem;
  color: #8b7355;
  text-align: right;
  font-style: normal;
}

@media (max-width: 640px) {
  .original-passage {
    padding: 1.05rem 1.1rem;
  }

  .original-text {
    font-size: .96rem;
    line-height: 1.85;
  }
}

/* v7 — 原文/译文成对展示（PDF 导入） */
.source-pair {
  margin: 1.35rem 0 0;
  border: 1px solid #e8dcc8;
  border-radius: .65rem;
  overflow: hidden;
  background: #fffcf7;
  box-shadow: 0 1px 0 rgba(255,255,255,.65) inset;
}

.source-pair .original-passage {
  margin: 0;
  border: none;
  border-radius: 0;
  box-shadow: none;
}

.source-pair .translation-box.merged {
  margin: 0;
  border: none;
  border-top: 1px dashed #dccbb5;
  border-radius: 0;
  background: #f7f3eb;
  padding: 1.1rem 1.45rem 1.25rem;
}

.source-pair .translation-box.merged p {
  margin: 0 0 .75rem;
  color: #4a4034;
  line-height: 1.85;
  font-size: .98rem;
}

.source-pair .translation-box.merged p:last-child {
  margin-bottom: 0;
}

.source-pair + .source-pair {
  margin-top: 1rem;
}


/* ============================================================
   v9 — 布局对齐 Harness-Agent-Book（2026-07-08）
   覆盖 v4/v5 的窄布局，恢复与 Harness 一致的宽布局
   ============================================================ */

.book-layout {
  max-width: 84rem;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  gap: 2.5rem;
  padding-top: 5rem;
}

.book-main {
  min-width: 0;
  display: block;
}

.book-article {
  max-width: 54rem;
}

.book-layout-index .book-article {
  max-width: 72rem;
}

.book-sidebar {
  position: sticky;
  top: 5rem;
  max-height: calc(100vh - 6rem);
  overflow-y: auto;
  padding-right: .5rem;
}

/* v9 的桌面宽布局位于文件末尾，需在其后重新声明移动端侧栏，
   否则桌面双栏规则会覆盖前面的响应式样式。 */
@media (max-width: 960px) {
  .book-layout {
    grid-template-columns: 1fr;
    padding-top: 4.5rem;
  }

  .book-main {
    width: 100%;
    min-width: 0;
  }

  .book-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 16rem;
    max-height: 100vh;
    padding: 5rem 1rem 2rem;
    border-right: 1px solid var(--line);
    background: #fff;
    box-shadow: 0 0 60px -20px rgba(15, 23, 42, .3);
    transform: translateX(-105%);
    transition: transform .25s ease;
    z-index: 55;
  }

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

  .book-sidebar-toggle {
    display: block;
  }
}

@media (max-width: 640px) {
  .book-layout {
    padding-right: 1rem;
    padding-left: 1rem;
  }
}