/* ═══════════════════════════════════════════════
   光湖知识库 · 主样式
   设计基线：简洁、深色主题、阅读友好
   ═══════════════════════════════════════════════ */

:root {
  --kb-bg: #0d1117;
  --kb-bg-secondary: #161b22;
  --kb-bg-tertiary: #21262d;
  --kb-border: #30363d;
  --kb-text: #e6edf3;
  --kb-text-muted: #8b949e;
  --kb-accent: #58a6ff;
  --kb-accent-hover: #79c0ff;
  --kb-danger: #f85149;
  --kb-success: #3fb950;
  --kb-warning: #d29922;
  --kb-font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
  --kb-font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  --kb-sidebar-width: 280px;
  --kb-header-height: 52px;
  --kb-radius: 6px;
}

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

body {
  font-family: var(--kb-font-sans);
  background: var(--kb-bg);
  color: var(--kb-text);
  line-height: 1.6;
  overflow: hidden;
}

/* ─── 布局 ─── */

.kb-app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

.kb-header {
  height: var(--kb-header-height);
  display: flex;
  align-items: center;
  padding: 0 16px;
  border-bottom: 1px solid var(--kb-border);
  background: var(--kb-bg-secondary);
  gap: 12px;
  flex-shrink: 0;
}

.kb-header-left {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.kb-header-center {
  flex: 1;
  display: flex;
  justify-content: center;
}

.kb-header-right {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.kb-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--kb-text);
  white-space: nowrap;
}

.kb-body {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* ─── 侧栏 ─── */

.kb-sidebar {
  width: var(--kb-sidebar-width);
  border-right: 1px solid var(--kb-border);
  background: var(--kb-bg-secondary);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  flex-shrink: 0;
}

.kb-sidebar-actions {
  padding: 12px;
  border-bottom: 1px solid var(--kb-border);
}

/* ─── 文档树 ─── */

.kb-tree {
  overflow-y: auto;
  padding: 8px 0;
  flex: 1;
}

.kb-tree-item {
  display: flex;
  align-items: center;
  padding: 6px 12px;
  cursor: pointer;
  gap: 6px;
  font-size: 13px;
  transition: background 0.15s;
  position: relative;
}

.kb-tree-item:hover {
  background: var(--kb-bg-tertiary);
}

.kb-tree-item.active {
  background: var(--kb-bg-tertiary);
  color: var(--kb-accent);
}

.kb-tree-icon {
  font-size: 14px;
  flex-shrink: 0;
}

.kb-tree-name {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.kb-tree-add {
  display: none;
  background: none;
  border: 1px solid var(--kb-border);
  color: var(--kb-text-muted);
  border-radius: 3px;
  width: 20px;
  height: 20px;
  cursor: pointer;
  font-size: 12px;
  line-height: 1;
}

.kb-tree-folder-header:hover .kb-tree-add {
  display: flex;
  align-items: center;
  justify-content: center;
}

.kb-tree-add:hover {
  color: var(--kb-accent);
  border-color: var(--kb-accent);
}

/* ─── 内容区 ─── */

.kb-content {
  flex: 1;
  overflow-y: auto;
  padding: 0;
}

/* ─── 编辑器 ─── */

.kb-editor {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 32px;
}

.kb-editor-meta {
  display: flex;
  gap: 16px;
  font-size: 12px;
  color: var(--kb-text-muted);
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--kb-border);
}

.kb-editor-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 12px;
  cursor: pointer;
  line-height: 1.3;
}

.kb-editor-title:hover {
  color: var(--kb-accent);
}

.kb-editor-title-input {
  width: 100%;
  font-size: 28px;
  font-weight: 700;
  background: var(--kb-bg-tertiary);
  border: 1px solid var(--kb-border);
  color: var(--kb-text);
  padding: 8px 12px;
  border-radius: var(--kb-radius);
  margin-bottom: 12px;
}

.kb-editor-toolbar {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
}

.kb-editor-edit-pane {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  min-height: 500px;
}

.kb-editor-textarea {
  width: 100%;
  min-height: 500px;
  background: var(--kb-bg-tertiary);
  border: 1px solid var(--kb-border);
  color: var(--kb-text);
  padding: 16px;
  border-radius: var(--kb-radius);
  font-family: var(--kb-font-mono);
  font-size: 14px;
  line-height: 1.7;
  resize: vertical;
  outline: none;
}

.kb-editor-textarea:focus {
  border-color: var(--kb-accent);
}

.kb-editor-preview-pane,
.kb-editor-read-pane {
  overflow-y: auto;
}

.kb-editor-read-pane {
  padding: 0;
}

/* ─── Markdown 渲染 ─── */

.kb-markdown-render {
  font-size: 15px;
  line-height: 1.8;
  color: var(--kb-text);
}

.kb-markdown-render h1 { font-size: 2em; margin: 1em 0 0.5em; border-bottom: 1px solid var(--kb-border); padding-bottom: 0.3em; }
.kb-markdown-render h2 { font-size: 1.5em; margin: 1em 0 0.5em; border-bottom: 1px solid var(--kb-border); padding-bottom: 0.3em; }
.kb-markdown-render h3 { font-size: 1.25em; margin: 1em 0 0.5em; }
.kb-markdown-render p { margin: 0.8em 0; }
.kb-markdown-render ul, .kb-markdown-render ol { margin: 0.8em 0; padding-left: 2em; }
.kb-markdown-render li { margin: 0.3em 0; }
.kb-markdown-render blockquote {
  border-left: 3px solid var(--kb-accent);
  padding: 0.5em 1em;
  margin: 1em 0;
  background: var(--kb-bg-tertiary);
  color: var(--kb-text-muted);
}
.kb-markdown-render code {
  background: var(--kb-bg-tertiary);
  padding: 2px 6px;
  border-radius: 3px;
  font-family: var(--kb-font-mono);
  font-size: 0.9em;
}
.kb-markdown-render pre {
  background: var(--kb-bg-tertiary);
  padding: 16px;
  border-radius: var(--kb-radius);
  overflow-x: auto;
  margin: 1em 0;
}
.kb-markdown-render pre code {
  background: none;
  padding: 0;
}
.kb-markdown-render table {
  border-collapse: collapse;
  width: 100%;
  margin: 1em 0;
}
.kb-markdown-render th, .kb-markdown-render td {
  border: 1px solid var(--kb-border);
  padding: 8px 12px;
  text-align: left;
}
.kb-markdown-render th {
  background: var(--kb-bg-tertiary);
  font-weight: 600;
}
.kb-markdown-render a {
  color: var(--kb-accent);
  text-decoration: none;
}
.kb-markdown-render a:hover {
  text-decoration: underline;
}
.kb-markdown-render img {
  max-width: 100%;
  border-radius: var(--kb-radius);
}
.kb-markdown-render hr {
  border: none;
  border-top: 1px solid var(--kb-border);
  margin: 2em 0;
}

/* ─── 搜索 ─── */

.kb-search {
  position: relative;
  width: 100%;
  max-width: 480px;
}

.kb-search-input-wrap {
  display: flex;
  align-items: center;
  background: var(--kb-bg-tertiary);
  border: 1px solid var(--kb-border);
  border-radius: var(--kb-radius);
  padding: 0 10px;
  gap: 6px;
}

.kb-search-input-wrap:focus-within {
  border-color: var(--kb-accent);
}

.kb-search-icon {
  font-size: 14px;
  flex-shrink: 0;
}

.kb-search-input {
  flex: 1;
  background: none;
  border: none;
  color: var(--kb-text);
  padding: 8px 0;
  font-size: 14px;
  outline: none;
}

.kb-search-input::placeholder {
  color: var(--kb-text-muted);
}

.kb-search-clear {
  background: none;
  border: none;
  color: var(--kb-text-muted);
  cursor: pointer;
  font-size: 14px;
  padding: 2px 4px;
}

.kb-search-loading {
  color: var(--kb-text-muted);
  font-size: 12px;
}

.kb-search-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--kb-bg-secondary);
  border: 1px solid var(--kb-border);
  border-radius: var(--kb-radius);
  margin-top: 4px;
  max-height: 360px;
  overflow-y: auto;
  z-index: 100;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}

.kb-search-result {
  padding: 10px 14px;
  cursor: pointer;
  border-bottom: 1px solid var(--kb-border);
}

.kb-search-result:last-child {
  border-bottom: none;
}

.kb-search-result:hover {
  background: var(--kb-bg-tertiary);
}

.kb-search-result-title {
  font-weight: 600;
  font-size: 14px;
  margin-bottom: 2px;
}

.kb-search-result-path {
  font-size: 11px;
  color: var(--kb-text-muted);
  margin-bottom: 4px;
}

.kb-search-result-snippet {
  font-size: 12px;
  color: var(--kb-text-muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.kb-search-empty {
  padding: 16px;
  text-align: center;
  color: var(--kb-text-muted);
  font-size: 13px;
}

/* ─── 版本历史 ─── */

.kb-history {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 32px;
}

.kb-history-title {
  font-size: 22px;
  margin-bottom: 8px;
}

.kb-history-hint {
  color: var(--kb-text-muted);
  font-size: 13px;
  margin-bottom: 20px;
}

.kb-history-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.kb-history-entry {
  display: flex;
  align-items: center;
  padding: 10px 14px;
  border-radius: var(--kb-radius);
  background: var(--kb-bg-secondary);
  border: 1px solid var(--kb-border);
  gap: 8px;
}

.kb-history-entry.selected {
  border-color: var(--kb-accent);
  background: var(--kb-bg-tertiary);
}

.kb-history-entry-main {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  font-size: 13px;
}

.kb-history-hash {
  font-family: var(--kb-font-mono);
  font-size: 12px;
  color: var(--kb-accent);
  background: var(--kb-bg-tertiary);
  padding: 2px 6px;
  border-radius: 3px;
  flex-shrink: 0;
}

.kb-history-message {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.kb-history-date {
  color: var(--kb-text-muted);
  font-size: 12px;
  flex-shrink: 0;
}

.kb-history-author {
  color: var(--kb-text-muted);
  font-size: 12px;
  flex-shrink: 0;
}

.kb-history-preview,
.kb-history-diff {
  margin-top: 20px;
  border: 1px solid var(--kb-border);
  border-radius: var(--kb-radius);
  overflow: hidden;
}

.kb-history-preview-header,
.kb-history-diff-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  background: var(--kb-bg-tertiary);
  border-bottom: 1px solid var(--kb-border);
  font-size: 13px;
}

.kb-history-preview-header button,
.kb-history-diff-header button {
  margin-left: auto;
}

.kb-history-preview-content {
  padding: 16px;
  font-family: var(--kb-font-mono);
  font-size: 13px;
  line-height: 1.6;
  white-space: pre-wrap;
  overflow-x: auto;
  max-height: 400px;
}

.kb-history-diff-stats {
  font-family: var(--kb-font-mono);
  font-size: 12px;
  color: var(--kb-success);
}

.kb-diff-hunk {
  border-bottom: 1px solid var(--kb-border);
}

.kb-diff-line {
  padding: 2px 14px;
  font-family: var(--kb-font-mono);
  font-size: 13px;
  line-height: 1.6;
  white-space: pre;
}

.kb-diff-line.add {
  background: rgba(63, 185, 80, 0.15);
  color: var(--kb-success);
}

.kb-diff-line.del {
  background: rgba(248, 81, 73, 0.15);
  color: var(--kb-danger);
}

.kb-diff-line.ctx {
  color: var(--kb-text-muted);
}

/* ─── 通用按钮 ─── */

.kb-btn-icon {
  background: none;
  border: none;
  color: var(--kb-text-muted);
  cursor: pointer;
  font-size: 16px;
  padding: 4px 8px;
  border-radius: var(--kb-radius);
}

.kb-btn-icon:hover {
  color: var(--kb-text);
  background: var(--kb-bg-tertiary);
}

.kb-btn-danger:hover {
  color: var(--kb-danger) !important;
}

.kb-btn-primary {
  background: var(--kb-accent);
  color: #fff;
  border: none;
  padding: 6px 16px;
  border-radius: var(--kb-radius);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
}

.kb-btn-primary:hover {
  background: var(--kb-accent-hover);
}

.kb-btn-secondary {
  background: var(--kb-bg-tertiary);
  color: var(--kb-text);
  border: 1px solid var(--kb-border);
  padding: 6px 16px;
  border-radius: var(--kb-radius);
  cursor: pointer;
  font-size: 13px;
}

.kb-btn-secondary:hover {
  border-color: var(--kb-text-muted);
}

.kb-btn-small {
  background: var(--kb-bg-tertiary);
  color: var(--kb-text-muted);
  border: 1px solid var(--kb-border);
  padding: 4px 10px;
  border-radius: var(--kb-radius);
  cursor: pointer;
  font-size: 12px;
  white-space: nowrap;
}

.kb-btn-small:hover {
  color: var(--kb-text);
  border-color: var(--kb-text-muted);
}

.kb-btn-tab {
  background: none;
  border: none;
  color: var(--kb-text-muted);
  cursor: pointer;
  padding: 6px 12px;
  border-radius: var(--kb-radius);
  font-size: 13px;
}

.kb-btn-tab:hover {
  background: var(--kb-bg-tertiary);
  color: var(--kb-text);
}

.kb-btn-tab.active {
  background: var(--kb-bg-tertiary);
  color: var(--kb-accent);
  font-weight: 600;
}

/* ─── 空状态 / 错误 / 加载 ─── */

.kb-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--kb-text-muted);
  gap: 8px;
}

.kb-empty-icon {
  font-size: 48px;
  margin-bottom: 8px;
}

.kb-empty-hint {
  font-size: 13px;
}

.kb-error {
  background: rgba(248, 81, 73, 0.1);
  border: 1px solid var(--kb-danger);
  color: var(--kb-danger);
  padding: 10px 16px;
  margin: 16px;
  border-radius: var(--kb-radius);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
}

.kb-error button {
  background: none;
  border: none;
  color: var(--kb-danger);
  cursor: pointer;
  font-size: 16px;
}

.kb-loading {
  padding: 24px;
  text-align: center;
  color: var(--kb-text-muted);
}

.kb-history-loading {
  padding: 24px;
  color: var(--kb-text-muted);
}

/* ─── 滚动条 ─── */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--kb-border);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--kb-text-muted);
}