/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #ffffff;
  --sidebar-bg: #f8f8f8;
  --text: #1a1a1a;
  --text-muted: #666;
  --border: #e0e0e0;
  --link: #4a6cf7;
  --link-hover: #3b5de7;
  --code-bg: #f4f4f5;
  --accent: #4a6cf7;
  --sidebar-width: 280px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: "SF Mono", "Fira Code", "JetBrains Mono", "Menlo", monospace;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 15px;
}

a { color: var(--link); text-decoration: none; }
a:hover { color: var(--link-hover); text-decoration: underline; }

/* === Layout === */
.app {
  display: flex;
  min-height: 100vh;
}

/* === Sidebar === */
.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  position: fixed;
  top: 0; left: 0; bottom: 0;
  overflow-y: auto;
  z-index: 100;
  padding: 0;
  transition: transform 0.2s;
}

.sidebar-header {
  padding: 20px 16px 12px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--sidebar-bg);
  z-index: 2;
}

.site-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  display: block;
  margin-bottom: 12px;
}
.site-title:hover { text-decoration: none; }

.search-box {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
  font-family: var(--font);
  outline: none;
  transition: border 0.15s;
}
.search-box:focus { border-color: var(--accent); }

.search-results {
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.search-results a {
  display: block;
  padding: 4px 8px;
  font-size: 13px;
  border-radius: 4px;
}
.search-results a:hover { background: #e8e8e8; text-decoration: none; }
.no-results { font-size: 13px; color: var(--text-muted); padding: 4px 8px; }

/* === Tree Nav === */
.tree-nav { padding: 12px 16px; }

.tree-item {
  padding: 3px 0;
  display: flex;
  align-items: center;
  gap: 4px;
}

.folder-toggle {
  cursor: pointer;
  user-select: none;
  font-size: 11px;
  color: var(--text-muted);
  width: 16px;
  display: inline-block;
  flex-shrink: 0;
}

.folder-label {
  font-size: 13px;
  color: var(--text-muted);
  cursor: pointer;
  user-select: none;
}

.tree-children { padding-left: 16px; }

.file-link {
  font-size: 13px;
  color: var(--text);
  padding: 2px 6px;
  border-radius: 4px;
  display: block;
  transition: background 0.1s;
}
.file-link:hover { background: #e8e8e8; text-decoration: none; }
.file-link.active {
  background: #e0e7ff;
  color: var(--accent);
  font-weight: 600;
}

/* === Main Content === */
.content {
  margin-left: var(--sidebar-width);
  flex: 1;
  padding: 40px 48px;
  max-width: 860px;
  width: 100%;
}

.breadcrumb {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb .current { color: var(--text); font-weight: 500; }

/* === Markdown Body === */
.markdown-body { }

.markdown-body h1 { font-size: 2em; margin: 0.67em 0 0.5em; font-weight: 700; border-bottom: 1px solid var(--border); padding-bottom: 8px; }
.markdown-body h2 { font-size: 1.5em; margin: 1.2em 0 0.5em; font-weight: 600; border-bottom: 1px solid var(--border); padding-bottom: 6px; }
.markdown-body h3 { font-size: 1.25em; margin: 1em 0 0.4em; font-weight: 600; }
.markdown-body h4, .markdown-body h5, .markdown-body h6 { margin: 0.8em 0 0.3em; font-weight: 600; }

.markdown-body p { margin: 0.6em 0; }
.markdown-body ul, .markdown-body ol { padding-left: 1.8em; margin: 0.6em 0; }
.markdown-body li { margin: 0.2em 0; }
.markdown-body blockquote {
  border-left: 3px solid var(--accent);
  padding: 4px 16px;
  margin: 0.8em 0;
  color: var(--text-muted);
  background: #f9f9fb;
}

.markdown-body code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 4px;
}

.markdown-body pre {
  background: var(--code-bg);
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1em 0;
  border: 1px solid var(--border);
  font-size: 13px;
  line-height: 1.5;
}
.markdown-body pre code {
  background: none;
  padding: 0;
  font-size: inherit;
}

.markdown-body table {
  border-collapse: collapse;
  width: 100%;
  margin: 1em 0;
}
.markdown-body th, .markdown-body td {
  border: 1px solid var(--border);
  padding: 8px 12px;
  text-align: left;
  font-size: 14px;
}
.markdown-body th { background: var(--sidebar-bg); font-weight: 600; }

.markdown-body img { max-width: 100%; border-radius: 6px; margin: 0.8em 0; }

.markdown-body hr { border: none; border-top: 1px solid var(--border); margin: 1.5em 0; }

/* Wikilinks */
a.wikilink { color: var(--accent); border-bottom: 1px dashed var(--accent); }
a.wikilink:hover { text-decoration: none; border-bottom-style: solid; }

/* Highlight & strikethrough */
.markdown-body mark { background: #fff3b0; padding: 1px 4px; border-radius: 3px; }
.markdown-body del { color: var(--text-muted); text-decoration: line-through; }

/* Tags */
span.tag {
  display: inline-block;
  background: #e8f0fe;
  color: #3b6fd4;
  padding: 1px 8px;
  border-radius: 12px;
  font-size: 0.85em;
  margin: 0 2px;
}

/* Folding */
.markdown-body h1, .markdown-body h2, .markdown-body h3 {
  cursor: pointer;
  position: relative;
}
.markdown-body h1::before, .markdown-body h2::before, .markdown-body h3::before {
  content: "▾";
  position: absolute;
  left: -20px;
  font-size: 0.7em;
  color: var(--text-muted);
  transition: transform 0.2s;
  top: 50%;
  transform: translateY(-50%) rotate(0deg);
}
.markdown-body h1.folded::before,
.markdown-body h2.folded::before,
.markdown-body h3.folded::before {
  transform: translateY(-50%) rotate(-90deg);
}
.markdown-body .folded + *,
.markdown-body .folded + * + *,
.markdown-body .folded + * + * + *,
.markdown-body .folded ~ * { /* fallback - JS controlled */ }
.folded-children { display: none; }

/* collapsible list items */
.markdown-body li.foldable {
  cursor: pointer;
  list-style-type: none;
}
.markdown-body li.foldable::marker { content: ""; }
.markdown-body li.foldable::before {
  content: "▾ ";
  font-size: 0.8em;
  color: var(--text-muted);
}
.markdown-body li.foldable.collapsed::before {
  content: "▸ ";
}

/* Welcome */
.welcome {
  text-align: center;
  padding: 80px 0;
  color: var(--text-muted);
}
.welcome h1 { font-size: 2em; margin-bottom: 12px; color: var(--text); border: none; }

/* Sidebar toggle (mobile) */
.sidebar-toggle {
  display: none;
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 10px;
  font-size: 16px;
  cursor: pointer;
}

/* === Responsive === */
@media (max-width: 768px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .content { margin-left: 0; padding: 24px 16px; }
  .sidebar-toggle { display: block; }
}