:root {
  --ink: #221f1c;
  --muted: #6d665c;
  --line: #e4ddd2;
  --paper: #fffdf8;
  --page: #f3eee6;
  --sidebar: #f7f2ea;
  --accent: #c43b2e;
  --accent-soft: #fff1ec;
  --code-bg: #1f2328;
  --shadow: 0 12px 40px rgba(50, 36, 20, 0.08);
  --sidebar-w: 300px;
  --toc-w: 220px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  color: var(--ink);
  background: var(--page);
  font: 16px/1.75 "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

.app {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  flex: 0 0 var(--sidebar-w);
  width: var(--sidebar-w);
  height: 100vh;
  overflow: auto;
  background: var(--sidebar);
  border-right: 1px solid var(--line);
}

.brand {
  padding: 22px 20px 10px;
}

.brand strong {
  display: block;
  font-size: 18px;
  letter-spacing: 0.02em;
}

.brand span {
  color: var(--muted);
  font-size: 12px;
}

.search-wrap {
  display: block;
  padding: 8px 16px 12px;
}

.search-wrap input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 8px 12px;
  background: #fff;
  color: var(--ink);
  font: inherit;
}

.search-wrap input:focus {
  outline: 2px solid rgba(196, 59, 46, 0.25);
  border-color: var(--accent);
}

.tree {
  padding: 0 10px 24px;
}

.tree details {
  margin: 2px 0;
}

.tree summary {
  list-style: none;
  cursor: pointer;
  padding: 6px 10px;
  border-radius: 8px;
  color: #3d3832;
  font-weight: 600;
  font-size: 13px;
}

.tree summary::-webkit-details-marker {
  display: none;
}

.tree summary:hover,
.tree a:hover {
  background: rgba(196, 59, 46, 0.06);
}

.tree .kids {
  margin-left: 10px;
  padding-left: 8px;
  border-left: 1px solid var(--line);
}

.tree a {
  display: block;
  padding: 5px 10px;
  border-radius: 8px;
  color: var(--ink);
  text-decoration: none;
  font-size: 13px;
  line-height: 1.45;
}

.tree a.active {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.tree em.kind {
  margin-left: 6px;
  color: var(--muted);
  font-style: normal;
  font-size: 11px;
  font-weight: 500;
}

.tree .empty {
  padding: 16px 12px;
  color: var(--muted);
  font-size: 13px;
}

.main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 28px;
  background: rgba(243, 238, 230, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
}

.menu-btn {
  display: none;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 8px;
  padding: 4px 10px;
  font: inherit;
  cursor: pointer;
}

.crumb {
  color: var(--muted);
  font-size: 13px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.stage {
  display: flex;
  justify-content: center;
  gap: 36px;
  padding: 8px 28px 0;
}

.content {
  flex: 1 1 720px;
  max-width: 760px;
  min-height: 60vh;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 36px 44px 48px;
}

.content .placeholder,
.content .error {
  color: var(--muted);
}

.content h1,
.content h2,
.content h3,
.content h4 {
  line-height: 1.35;
  scroll-margin-top: 72px;
}

.content h1 {
  margin: 0 0 20px;
  font-size: 30px;
}

.content h2 {
  margin: 36px 0 12px;
  padding-top: 8px;
  border-top: 1px solid var(--line);
  font-size: 22px;
}

.content h3 {
  margin: 28px 0 10px;
  font-size: 18px;
}

.content p {
  margin: 0 0 14px;
}

.content a {
  color: #9a2c22;
}

.content img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 16px auto;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: #fff;
}

.content blockquote {
  margin: 16px 0;
  padding: 10px 16px;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  color: #4a3b37;
}

.content blockquote p:last-child {
  margin-bottom: 0;
}

.content table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14px;
}

.content th,
.content td {
  border: 1px solid var(--line);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

.content th {
  background: #f7f1e8;
}

.content pre {
  overflow: auto;
  margin: 16px 0;
  padding: 14px 16px;
  border-radius: 12px;
  background: var(--code-bg);
  color: #e8e6e3;
  font-size: 13px;
  line-height: 1.55;
}

.content pre code.hljs {
  display: block;
  background: transparent;
  padding: 0;
  color: inherit;
}

.content .hljs-comment,
.content .hljs-quote {
  color: #8b8680;
  font-style: italic;
}

.content .hljs-keyword,
.content .hljs-selector-tag,
.content .hljs-literal,
.content .hljs-name {
  color: #f0a36a;
}

.content .hljs-string,
.content .hljs-doctag,
.content .hljs-template-tag,
.content .hljs-addition {
  color: #8fd19e;
}

.content .hljs-number,
.content .hljs-attr,
.content .hljs-variable,
.content .hljs-template-variable {
  color: #7ec8e3;
}

.content .hljs-title,
.content .hljs-title.class_,
.content .hljs-title.function_,
.content .hljs-section {
  color: #d7b4ff;
}

.content .hljs-built_in,
.content .hljs-type,
.content .hljs-params {
  color: #f3d37a;
}

.content .hljs-meta,
.content .hljs-subst,
.content .hljs-symbol {
  color: #c9c2b8;
}

.content .hljs-deletion {
  color: #f0a0a0;
}

.content code {
  font-family: Consolas, "Sarasa Mono SC", "Microsoft YaHei Mono", monospace;
  font-size: 0.92em;
}

.content :not(pre) > code {
  background: #f3ece3;
  border-radius: 5px;
  padding: 1px 5px;
}

.content hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 28px 0;
}

.content li + li {
  margin-top: 4px;
}

.content .mermaid {
  margin: 20px 0;
  padding: 16px;
  overflow: auto;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
}

.toc {
  position: sticky;
  top: 72px;
  flex: 0 0 var(--toc-w);
  width: var(--toc-w);
  align-self: flex-start;
  max-height: calc(100vh - 96px);
  overflow: auto;
  padding: 8px 0 24px;
}

.toc strong {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.toc a {
  display: block;
  padding: 3px 0;
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  line-height: 1.4;
}

.toc a.depth-3 {
  padding-left: 12px;
}

.toc a.depth-4 {
  padding-left: 22px;
}

.toc a:hover,
.toc a.active {
  color: var(--accent);
}

.pager {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  max-width: 760px;
  width: 100%;
  margin: 0 auto;
  padding: 20px 28px 40px;
}

.pager a {
  flex: 1;
  max-width: 48%;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--paper);
  color: var(--ink);
  text-decoration: none;
  font-size: 13px;
}

.pager a span {
  display: block;
  color: var(--muted);
  font-size: 12px;
}

.pager a.next {
  text-align: right;
  margin-left: auto;
}

.backdrop {
  position: fixed;
  inset: 0;
  background: rgba(34, 31, 28, 0.35);
  z-index: 8;
}

@media (max-width: 1200px) {
  .toc {
    display: none;
  }
}

@media (max-width: 860px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    z-index: 9;
    transform: translateX(-105%);
    transition: transform 0.2s ease;
  }

  body.nav-open .sidebar {
    transform: none;
  }

  .menu-btn {
    display: inline-block;
  }

  .content {
    padding: 24px 18px 36px;
    border-radius: 0;
    border-left: 0;
    border-right: 0;
  }

  .stage,
  .topbar,
  .pager {
    padding-left: 0;
    padding-right: 0;
  }
}