:root {
  color-scheme: light;
  --bg: #f7f8fb;
  --panel: #ffffff;
  --panel-soft: #f0f3f8;
  --text: #1d2433;
  --muted: #6b7280;
  --line: #dfe5ee;
  --accent: #0f766e;
  --accent-soft: #dff5f1;
  --code-bg: #111827;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
}

.app-shell {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  min-height: 100vh;
}

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

.brand {
  position: sticky;
  top: 0;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 20px 18px 14px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}

.brand strong {
  display: block;
  font-size: 18px;
}

.brand span {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 13px;
}

.search {
  display: block;
  padding: 14px 18px 10px;
}

.search span {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 13px;
}

.search input {
  width: 100%;
  height: 38px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel-soft);
  color: var(--text);
  font-size: 14px;
  outline: none;
}

.search input:focus {
  border-color: var(--accent);
  background: #fff;
}

.tree,
.search-results {
  padding: 8px 10px 22px;
}

.tree ul {
  margin: 0;
  padding-left: 14px;
  list-style: none;
}

.tree > ul {
  padding-left: 0;
}

.folder-label,
.doc-link,
.result-link {
  display: flex;
  align-items: center;
  width: 100%;
  min-height: 32px;
  gap: 7px;
  padding: 6px 8px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: inherit;
  text-align: left;
  text-decoration: none;
  font: inherit;
  font-size: 14px;
  cursor: pointer;
}

.folder-label {
  color: #334155;
  font-weight: 650;
}

.doc-link {
  color: #475569;
}

.doc-link.active {
  background: var(--accent-soft);
  color: #0f4f49;
  font-weight: 650;
}

.folder-label:hover,
.doc-link:hover,
.result-link:hover {
  background: var(--panel-soft);
}

.caret {
  width: 16px;
  color: var(--muted);
  text-align: center;
}

.folder.collapsed > ul {
  display: none;
}

.folder.collapsed > .folder-label .caret {
  transform: rotate(-90deg);
}

.search-results {
  border-bottom: 1px solid var(--line);
}

.result-link {
  display: block;
  margin-bottom: 6px;
}

.result-link strong {
  display: block;
  font-size: 14px;
}

.result-link span {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
}

.reader {
  min-width: 0;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 58px;
  padding: 0 28px;
  border-bottom: 1px solid var(--line);
  background: rgba(247, 248, 251, 0.9);
  backdrop-filter: blur(12px);
}

.crumbs {
  min-width: 0;
  flex: 1;
  overflow: hidden;
  color: var(--muted);
  font-size: 14px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.source-link {
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 7px;
  color: #334155;
  text-decoration: none;
  font-size: 13px;
}

.content {
  width: min(920px, calc(100vw - 390px));
  margin: 0 auto;
  padding: 42px 0 96px;
}

.content h1,
.content h2,
.content h3,
.content h4 {
  color: #111827;
  line-height: 1.35;
}

.content h1 {
  margin: 0 0 22px;
  font-size: 34px;
}

.content h2 {
  margin-top: 38px;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-size: 24px;
}

.content h3 {
  margin-top: 28px;
  font-size: 19px;
}

.content p,
.content li {
  font-size: 16px;
  line-height: 1.82;
}

.content a {
  color: var(--accent);
}

.content table {
  width: 100%;
  margin: 18px 0;
  border-collapse: collapse;
  overflow: hidden;
  border-radius: 8px;
  font-size: 14px;
}

.content th,
.content td {
  padding: 10px 12px;
  border: 1px solid var(--line);
  vertical-align: top;
}

.content th {
  background: #eef2f7;
  text-align: left;
}

.content blockquote {
  margin: 18px 0;
  padding: 2px 18px;
  border-left: 4px solid var(--accent);
  background: #ecfdf5;
  color: #334155;
}

.content code {
  padding: 2px 5px;
  border-radius: 5px;
  background: #e5e7eb;
  font-family: "SFMono-Regular", Consolas, monospace;
}

.content pre {
  overflow: auto;
  padding: 16px;
  border-radius: 8px;
  background: var(--code-bg);
  color: #e5e7eb;
}

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

.empty-state {
  padding: 72px 0;
  color: var(--muted);
  text-align: center;
}

.icon-button {
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
  font-size: 20px;
  cursor: pointer;
}

.mobile-only {
  display: none;
}

@media (max-width: 860px) {
  .app-shell {
    display: block;
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 4;
    width: min(360px, 88vw);
    transform: translateX(-105%);
    transition: transform 160ms ease;
    box-shadow: 0 20px 60px rgba(15, 23, 42, 0.28);
  }

  body.nav-open .sidebar {
    transform: translateX(0);
  }

  .mobile-only {
    display: inline-grid;
    place-items: center;
  }

  .topbar {
    padding: 0 16px;
  }

  .content {
    width: min(100% - 32px, 920px);
    padding-top: 28px;
  }

  .content h1 {
    font-size: 28px;
  }
}