/* 深色主题 */
* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #1e1e2e;
  --bg-panel: #262637;
  --bg-input: #1a1a28;
  --border: #3a3a52;
  --text: #e4e4f0;
  --text-dim: #9a9ab0;
  --accent: #4fc3f7;
  --accent-dark: #2b93c7;
  --danger: #ef5350;
}

/* 亮色主题(仅覆盖变量,画布/3D 场景颜色由 JS 调色板同步) */
body.light {
  --bg: #f2f3f8;
  --bg-panel: #ffffff;
  --bg-input: #eef0f6;
  --border: #d2d5e2;
  --text: #23233a;
  --text-dim: #6a6a80;
  --accent: #1976d2;
  --accent-dark: #1565c0;
  --danger: #d32f2f;
}

html, body { height: 100%; }
body {
  font-family: "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  font-size: 14px;
}

/* 顶栏 */
header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 14px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
  flex: 0 0 auto;
}
.logo { font-size: 16px; font-weight: bold; color: var(--accent); }
.spacer { flex: 1; }

.tabs { display: flex; gap: 4px; }
.tab {
  padding: 6px 18px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  border-radius: 6px;
}
.tab.active { background: var(--accent-dark); color: #fff; border-color: var(--accent-dark); }

/* 精度调节 */
.precision { display: flex; align-items: center; gap: 6px; color: var(--text-dim); font-size: 13px; }
.precision input[type="range"] { width: 110px; accent-color: var(--accent); }
.precision input[type="number"] {
  width: 76px;
  padding: 5px 6px;
  font-size: 14px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--accent);
  text-align: center;
}

.btn {
  padding: 6px 14px;
  border: 1px solid var(--border);
  background: var(--bg-input);
  color: var(--text);
  cursor: pointer;
  border-radius: 6px;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent-dark); border-color: var(--accent-dark); color: #fff; }
.btn.primary:hover { background: var(--accent); }
.btn.small { padding: 2px 10px; font-size: 12px; }
.btn.tiny { padding: 0 7px; font-size: 12px; margin-left: 6px; flex: 0 0 auto; }

/* 主区域三栏 */
.main {
  flex: 1;
  display: flex;
  min-height: 0;
}

#sidebar {
  width: 320px;
  flex: 0 0 auto;
  overflow-y: auto;
  border-right: 1px solid var(--border);
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
}
.panel h2, #infoPanel h2 {
  font-size: 13px;
  color: var(--text-dim);
  margin-bottom: 8px;
  font-weight: 600;
  letter-spacing: 1px;
}
.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
  position: sticky; /* 侧栏滚动时「函数列表」表头保持可见 */
  top: 0;
  z-index: 4;
  padding: 4px 0;
  background: var(--bg-panel);
}
.panel-head h2 { margin-bottom: 0; }
.panel-head-btns { display: flex; gap: 6px; }

.expr-row { display: flex; gap: 6px; position: relative; }
.expr-input {
  flex: 1;
  min-width: 0;
  padding: 7px 10px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-family: Consolas, monospace;
  font-size: 14px;
}
.expr-input:focus { outline: none; border-color: var(--accent); }

textarea#dataInput,
textarea#tmText {
  width: 100%;
  box-sizing: border-box;
  padding: 6px 8px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-family: Consolas, monospace;
  font-size: 13px;
  resize: vertical;
}
textarea#dataInput:focus,
textarea#tmText:focus { outline: none; border-color: var(--accent); }

/* 文本模式:查找/替换输入框 */
.tm-input {
  width: 0;
  flex: 1;
  min-width: 0;
  padding: 4px 5px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  font-family: Consolas, monospace;
  font-size: 12px;
}
.tm-input:focus { outline: none; border-color: var(--accent); }

.error { color: var(--danger); font-size: 12px; min-height: 0; margin-top: 4px; }
.error:empty { display: none; }
.muted { color: var(--text-dim); font-size: 12px; }

/* 虚拟键盘 */
#keyboard {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 4px;
  margin-top: 8px;
}
#keyboard button {
  padding: 6px 0;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  cursor: pointer;
  font-family: Consolas, monospace;
  font-size: 13px;
}
#keyboard button:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
#keyboard button.param-key { color: #ffd54f; border-color: #7a6520; }

/* 表达式输入自动补全下拉(相对 .expr-row 定位) */
.suggest-box {
  position: absolute;
  left: 0;
  top: calc(100% + 2px);
  z-index: 40;
  min-width: 160px;
  max-height: 250px;
  overflow-y: auto;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 6px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.4);
  font-family: Consolas, monospace;
  font-size: 13px;
}
.suggest-item { padding: 4px 10px; cursor: pointer; color: var(--text); }
.suggest-item:hover, .suggest-item.active { background: var(--accent-dark); }

/* 函数列表 */
.func-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 6px;
  background: var(--bg-input);
}
.func-item.hidden-func { opacity: 0.45; }
.color-dot {
  width: 12px; height: 12px;
  border-radius: 50%;
  flex: 0 0 auto;
}
.func-expr {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-family: Consolas, monospace;
  font-size: 13px;
  cursor: text;
}
.func-expr:hover { color: var(--accent); }
.func-edit-input {
  flex: 1;
  min-width: 0;
  padding: 2px 6px;
  background: var(--bg-panel);
  border: 1px solid var(--accent);
  border-radius: 4px;
  color: var(--text);
  font-family: Consolas, monospace;
  font-size: 13px;
}
.func-edit-input:focus { outline: none; }
/* 行内编辑表达式失败时就地显示的错误(列表项下方,小字红字) */
.func-edit-error { color: var(--danger); font-size: 11px; margin: -2px 0 6px 20px; }
.type-badge {
  font-size: 10px;
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--border);
  color: var(--text-dim);
  flex: 0 0 auto;
}

/* 文件夹分组 */
.folder-block { margin-bottom: 6px; }
.folder-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 6px;
  background: var(--bg-panel);
}
.folder-arrow { padding: 2px 6px; flex: 0 0 auto; }
.folder-name {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 13px;
  cursor: text;
}
.folder-name:hover { color: var(--accent); }
.folder-count { flex: 0 0 auto; }
.folder-block .func-item { margin-left: 16px; } /* 缩进表示归属 */
.folder-move {
  flex: 0 0 auto;
  max-width: 64px;
  padding: 2px 2px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  font-size: 11px;
}

/* 参数 */
.param-add { display: flex; gap: 4px; }
.param-add input {
  width: 0;
  flex: 1;
  padding: 5px 6px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
}
.param-add input:first-child { flex: 1.2; }
.param-hint { font-size: 11px; color: var(--text-dim); margin-top: 4px; }

.param-item { margin-top: 8px; }
.param-item .param-head {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: Consolas, monospace;
}
.param-item .param-name { color: #ffd54f; font-weight: bold; }
.param-item input[type="range"] { flex: 1; accent-color: var(--accent); }
.param-item input[type="number"] {
  width: 64px;
  padding: 3px 5px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
}
.param-del { margin-left: auto; }

/* 坐标范围 */
.check-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  font-size: 12px;
  color: var(--text-dim);
  cursor: pointer;
}
.check-row input { accent-color: var(--accent); }
.range-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  margin-bottom: 8px;
}
.range-grid label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-dim);
}
.range-grid input {
  width: 0;
  flex: 1;
  padding: 5px 6px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
}

/* 视图区 */
#viewWrap {
  flex: 1;
  min-width: 0;
  position: relative;
  background: #14141f;
}
#canvas2d, #view3d {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
#view3d { display: none; }
#canvas2d { cursor: grab; }
#canvas2d.dragging { cursor: grabbing; }
#canvas2d.roi-active { cursor: crosshair; }
#canvas2d.digitize-active { cursor: crosshair; }
body.light #viewWrap { background: #ffffff; }
body.light #traceTip { background: rgba(255, 255, 255, 0.94); }

/* 信息面板 */
#infoPanel {
  width: 340px;
  flex: 0 0 auto;
  overflow-y: auto;
  border-left: 1px solid var(--border);
  background: var(--bg-panel);
  padding: 12px;
}
.info-expr {
  font-family: Consolas, monospace;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 10px;
  margin-bottom: 10px;
  word-break: break-all;
}
.info-section { margin-bottom: 12px; }
.info-section h3 {
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 4px;
}
.info-item {
  padding: 3px 0 3px 8px;
  font-size: 13px;
  overflow-x: auto;
}
.info-item .tag {
  font-size: 11px;
  color: var(--text-dim);
  margin-right: 6px;
}
.info-item .numeric-tag { color: #ffb74d; font-size: 11px; }
.info-note { font-size: 12px; color: var(--text-dim); margin-bottom: 10px; }
.info-loading { color: var(--accent); }
.katex { font-size: 1.05em; }

/* 分步讲解(分步求导/分步积分) */
.step-details summary {
  cursor: pointer;
  font-size: 12px;
  color: var(--text-dim);
  margin-bottom: 4px;
}
.step-list { margin: 4px 0 8px; padding-left: 22px; font-size: 13px; }
.step-list li { margin-bottom: 8px; overflow-x: auto; }
.step-list b { color: var(--accent); font-weight: normal; margin-right: 6px; }
.step-list .step-note { display: block; font-size: 12px; color: var(--text-dim); }

/* 信息面板分块 + 数值表格 */
.info-block { margin-bottom: 18px; }
.table-controls { display: flex; flex-direction: column; gap: 6px; margin-bottom: 8px; }
.table-controls select {
  padding: 5px 6px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  font-family: Consolas, monospace;
  max-width: 100%;
}
.table-range { display: flex; gap: 6px; }
.table-range input {
  width: 0;
  flex: 1;
  padding: 5px 6px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
}
.table-btns { display: flex; gap: 6px; }
#tableOut { max-height: 320px; overflow: auto; }
.val-table {
  width: 100%;
  border-collapse: collapse;
  font-family: Consolas, monospace;
  font-size: 12px;
}
.val-table th, .val-table td {
  border: 1px solid var(--border);
  padding: 3px 8px;
  text-align: right;
}
.val-table th { background: var(--bg-input); color: var(--accent); position: sticky; top: 0; }

/* 数据面板:CSV 预览表 */
.data-preview-table {
  width: 100%;
  border-collapse: collapse;
  font-family: Consolas, monospace;
  font-size: 12px;
  margin-top: 6px;
}
.data-preview-table th, .data-preview-table td {
  border: 1px solid var(--border);
  padding: 2px 6px;
  text-align: right;
}
.data-preview-table th { background: var(--bg-input); color: var(--accent); }

/* 工具面板 */
.tool-row {
  display: flex;
  flex-wrap: wrap; /* 控件较多时换行,避免溢出 340px 信息面板 */
  gap: 6px;
  margin-top: 6px;
  align-items: center;
}
.tool-row > .btn { flex: 0 0 auto; }
.tool-row select {
  width: 0;
  flex: 1;
  min-width: 0;
  padding: 4px 5px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  font-family: Consolas, monospace;
  font-size: 12px;
}
.tool-row .bound {
  width: 52px;
  flex: 0 1 auto; /* 空间不足时可收缩(下限 38px),配合 tool-row 换行防溢出 */
  min-width: 38px;
  padding: 4px 5px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  font-family: Consolas, monospace;
  font-size: 12px;
}
.tool-label { font-size: 12px; color: var(--text-dim); flex: 1; }

/* 追踪提示框 */
#traceTip {
  display: none;
  position: absolute;
  z-index: 5;
  padding: 3px 8px;
  background: rgba(20, 20, 31, 0.92);
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text);
  font-family: Consolas, monospace;
  font-size: 12px;
  pointer-events: none;
  white-space: nowrap;
}

/* 参数动画播放按钮 */
.param-play { padding: 2px 7px; }

/* 参数动画录制 */
.rec-row { margin-top: 8px; }
.btn.recording { background: #c62828; border-color: #c62828; color: #fff; }

/* 顶栏撤销/重做图标按钮 */
.undo-group { display: flex; gap: 4px; }
.btn.icon { padding: 6px 10px; font-size: 15px; line-height: 1; }

/* 下拉菜单(顶栏 设置 / 导出):开合状态在 .dropdown 的 open 类上 */
.dropdown { position: relative; }
.dropdown-body {
  display: none;
  position: absolute;
  right: 0;
  top: calc(100% + 4px);
  z-index: 60;
  min-width: 240px;
  max-height: 72vh;
  overflow-y: auto;
  padding: 8px;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
}
.dropdown.open .dropdown-body { display: block; }
.dropdown.open .dropdown-btn { border-color: var(--accent); }
.dropdown-body > .btn {
  display: block;
  width: 100%;
  margin-top: 4px;
  text-align: left;
}
.dropdown-body .check-row { margin-top: 6px; }
.dropdown-sep { height: 1px; background: var(--border); margin: 8px 0; }

/* 手风琴分组(左侧栏 / 工具面板共用):chevron 按 open 类切换 ▸/▾ */
.acc-head {
  display: flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  padding: 8px 10px;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 13px;
  letter-spacing: 1px;
}
.acc-head:hover { border-color: var(--accent); color: var(--text); }
.acc-head::before { content: '▸'; color: var(--accent); flex: 0 0 auto; }
.acc-group.open > .acc-head::before { content: '▾'; }
.acc-body { display: none; }
.acc-group.open > .acc-body { display: block; margin-top: 8px; }
/* 左侧栏:组内容器纵向排列各面板(组间距由 #sidebar 的 flex gap 提供) */
#sidebar > .acc-group.open > .acc-body { display: flex; flex-direction: column; gap: 10px; }
#toolsAccordion { margin-top: 8px; display: flex; flex-direction: column; gap: 8px; }

/* 信息面板标签页(分析 / 数据) */
.info-tabs { margin-bottom: 12px; }
.info-tabs .tab { flex: 1; }

/* 画布角部缩放按钮(仅 2D 显示;半透明悬浮,悬停加深) */
.corner-controls {
  position: absolute;
  right: 14px;
  bottom: 14px;
  z-index: 6;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.corner-controls button {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: rgba(38, 38, 55, 0.6);
  color: var(--text);
  cursor: pointer;
  font-size: 16px;
  line-height: 1;
}
.corner-controls button:hover { background: rgba(38, 38, 55, 0.92); border-color: var(--accent); }
body.light .corner-controls button { background: rgba(255, 255, 255, 0.65); }
body.light .corner-controls button:hover { background: rgba(255, 255, 255, 0.95); }

/* 底部状态栏:左 坐标 / 中 模式 / 右 CAS 引擎 */
#statusBar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 3px 12px;
  background: var(--bg-panel);
  border-top: 1px solid var(--border);
  font-size: 12px;
  color: var(--text-dim);
  white-space: nowrap;
}
#statusCoords {
  min-width: 230px;
  font-family: Consolas, monospace;
}
#statusMode { flex: 1; text-align: center; overflow: hidden; text-overflow: ellipsis; }
#statusCas { flex: 0 0 auto; }

/* ---------- M8 视觉打磨 ---------- */

/* 细滚动条(侧栏 / 信息面板 / 下拉菜单 / 命令列表;颜色随主题变量,亮暗自适应) */
#sidebar, #infoPanel, .dropdown-body, .cmdk-list {
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
#sidebar::-webkit-scrollbar, #sidebar *::-webkit-scrollbar,
#infoPanel::-webkit-scrollbar, #infoPanel *::-webkit-scrollbar,
.dropdown-body::-webkit-scrollbar,
.cmdk-list::-webkit-scrollbar { width: 8px; height: 8px; }
#sidebar::-webkit-scrollbar-thumb, #sidebar *::-webkit-scrollbar-thumb,
#infoPanel::-webkit-scrollbar-thumb, #infoPanel *::-webkit-scrollbar-thumb,
.dropdown-body::-webkit-scrollbar-thumb,
.cmdk-list::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
#sidebar::-webkit-scrollbar-thumb:hover, #sidebar *::-webkit-scrollbar-thumb:hover,
#infoPanel::-webkit-scrollbar-thumb:hover, #infoPanel *::-webkit-scrollbar-thumb:hover,
.dropdown-body::-webkit-scrollbar-thumb:hover,
.cmdk-list::-webkit-scrollbar-thumb:hover { background: var(--text-dim); }
#sidebar::-webkit-scrollbar-track, #sidebar *::-webkit-scrollbar-track,
#infoPanel::-webkit-scrollbar-track, #infoPanel *::-webkit-scrollbar-track,
.dropdown-body::-webkit-scrollbar-track,
.cmdk-list::-webkit-scrollbar-track { background: transparent; }

/* 键盘导航焦点框(鼠标点击不触发;:focus 已自定义边框色的输入框不受影响) */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }

/* 信息面板:分块标题在滚动时吸附顶部(与 .panel-head 一致) */
#infoPanel .info-block > h2 {
  position: sticky;
  top: 0;
  z-index: 4;
  padding: 4px 0;
  background: var(--bg-panel);
}

/* 亮色主题:修正硬编码黄色的对比度(参数名 / 数值标记) */
body.light .param-item .param-name { color: #a8791a; }
body.light #keyboard button.param-key { color: #a8791a; border-color: #cbb26a; }
body.light .info-item .numeric-tag { color: #c77800; }

/* ---------- 命令搜索(Ctrl+K) ---------- */
.cmdk-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  background: rgba(0, 0, 0, 0.35);
}
body.light .cmdk-overlay { background: rgba(40, 40, 60, 0.25); }
.cmdk-panel {
  margin-top: 12vh;
  width: min(560px, 92vw);
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 10px 32px rgba(0, 0, 0, 0.45);
  overflow: hidden;
}
.cmdk-input {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-input);
  border: none;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-size: 14px;
  outline: none;
}
.cmdk-list {
  max-height: 46vh;
  overflow-y: auto;
  padding: 4px;
}
.cmdk-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
}
.cmdk-item.active { background: var(--accent-dark); color: #fff; }
.cmdk-item.active .cmdk-cat,
.cmdk-item.active .cmdk-kw { color: rgba(255, 255, 255, 0.75); background: transparent; }
.cmdk-title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.cmdk-kw {
  font-size: 11px;
  color: var(--text-dim);
  font-family: Consolas, monospace;
  flex: 0 0 auto;
}
.cmdk-cat {
  font-size: 10px;
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--border);
  color: var(--text-dim);
  flex: 0 0 auto;
}
.cmdk-empty {
  padding: 12px;
  text-align: center;
  color: var(--text-dim);
  font-size: 12px;
}

/* ---------- 使用手册(F1 帮助模态框) ---------- */
/* 与 .cmdk-overlay 同一层级(z-index 100):两者互斥,打开一个即关闭另一个 */
.help-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  background: rgba(0, 0, 0, 0.35);
}
body.light .help-overlay { background: rgba(40, 40, 60, 0.25); }
.help-panel {
  margin-top: 6vh;
  width: min(900px, 94vw);
  height: 76vh;
  display: flex;
  flex-direction: column;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 10px 32px rgba(0, 0, 0, 0.45);
  overflow: hidden;
}
.help-top {
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--border);
  flex: 0 0 auto;
}
.help-search {
  flex: 1;
  min-width: 0;
  padding: 10px 14px;
  background: var(--bg-input);
  border: none;
  color: var(--text);
  font-size: 14px;
  outline: none;
}
.help-close {
  flex: 0 0 auto;
  padding: 6px 16px;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 20px;
  cursor: pointer;
}
.help-close:hover { color: var(--accent); }
.help-body {
  flex: 1;
  min-height: 0;
  display: flex;
}
.help-nav {
  flex: 0 0 280px;
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border);
  min-height: 0;
}
.help-cats {
  flex: 0 0 auto;
  max-height: 40%;
  overflow-y: auto;
  padding: 4px;
  border-bottom: 1px solid var(--border);
}
.help-cat {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 10px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  color: var(--text);
}
.help-cat.active { background: var(--accent-dark); color: #fff; }
.help-cat.active .help-cat-count { color: rgba(255, 255, 255, 0.75); background: transparent; }
.help-cat-name { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.help-cat-count {
  font-size: 10px;
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--border);
  color: var(--text-dim);
  flex: 0 0 auto;
}
.help-entries {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 4px;
}
.help-entry {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 5px 10px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  color: var(--text);
}
.help-entry.active { background: var(--bg-input); }
.help-entry.current { color: var(--accent); }
.help-entry-cat {
  font-size: 10px;
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--border);
  color: var(--text-dim);
  flex: 0 0 auto;
}
.help-empty {
  padding: 12px;
  text-align: center;
  color: var(--text-dim);
  font-size: 12px;
}
.help-content {
  flex: 1;
  min-width: 0;
  overflow-y: auto;
  padding: 14px 20px;
  font-size: 13px;
  line-height: 1.7;
}
.help-content-title {
  margin: 0 0 10px;
  font-size: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.help-content-cat {
  font-size: 10px;
  font-weight: normal;
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--border);
  color: var(--text-dim);
  flex: 0 0 auto;
}
.help-content-body p { margin: 6px 0; }
.help-content-body ul { margin: 6px 0; padding-left: 20px; }
.help-content-body li { margin: 3px 0; }
.help-content-body code {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0 4px;
  font-family: Consolas, monospace;
  font-size: 12px;
  color: var(--accent);
}
.help-content-body b { color: var(--accent); font-weight: 600; }
/* 帮助面板内滚动条与全局一致 */
.help-cats, .help-entries, .help-content {
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

/* ---------- 更新检查(js/updatecheck.js,仅桌面版) ---------- */
/* 模态框与 .help-overlay 同层级同风格;横幅为右上角浮动卡片(z-index 90,低于模态框) */
.uc-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  background: rgba(0, 0, 0, 0.35);
}
body.light .uc-overlay { background: rgba(40, 40, 60, 0.25); }
.uc-panel {
  margin-top: 14vh;
  width: min(440px, 92vw);
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 10px 32px rgba(0, 0, 0, 0.45);
  padding: 20px 22px;
}
.uc-title { font-size: 16px; margin-bottom: 12px; color: var(--text); }
.uc-text { font-size: 14px; line-height: 1.7; margin: 6px 0; color: var(--text); }
.uc-muted { color: var(--text-dim); font-size: 13px; }
.uc-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 16px;
}
.uc-foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}
.uc-check {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text);
  cursor: pointer;
  user-select: none;
}
.uc-banner {
  position: fixed;
  top: 12px;
  right: 12px;
  z-index: 90;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--bg-panel);
  border: 1px solid var(--accent-dark);
  border-radius: 8px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
}
.uc-banner-text { font-size: 13px; color: var(--text); }
.uc-banner-close {
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 16px;
  cursor: pointer;
  padding: 0 2px;
}
.uc-banner-close:hover { color: var(--accent); }