/* ============================================
   Excel 函数练习工作台 - 样式表
   风格：数据分析工作台 + Excel 表格练习
   ============================================ */

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

:root {
  --bg-page: #FBFCFB;
  --bg-sidebar: #FFFFFF;
  --bg-toolbar: #FFFFFF;
  --bg-content: #FBFCFB;
  --bg-card: #FFFFFF;
  --bg-table-header: #EEF5F0;
  --bg-table-row-alt: #F4F9F6;
  --bg-input: #FFFFFF;
  --bg-hover: #EEF5F0;

  --color-primary: #1F6B43;
  --color-primary-light: #2A8457;
  --color-primary-dark: #0F3D28;
  --color-primary-bg: #EEF5F0;
  --color-accent: #F5A623;
  --color-accent-soft: #FFD766;

  --color-blue: #2563EB;
  --color-blue-light: #DBEAFE;
  --color-success: #1F8A4D;
  --color-success-bg: #E6F5EC;
  --color-error: #DC2626;
  --color-error-bg: #FEE2E2;
  --color-warning: #B7791F;
  --color-warning-bg: #FBEEDA;
  --color-info: #0891B2;
  --color-info-bg: #CFFAFE;

  --text-primary: #0F2419;
  --text-secondary: #6B7D74;
  --text-tertiary: #9AABA3;
  --text-inverse: #FFFFFF;

  --border-color: #E8EEEA;
  --border-light: #F1F6F3;
  --border-table: #D8E3DD;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -1px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -2px rgba(0,0,0,0.04);

  --sidebar-width: 220px;
  --right-panel-width: 280px;
  --toolbar-height: 56px;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "Cascadia Code", "Consolas", "Courier New", monospace;
}

html { font-size: 14px; }
body {
  font-family: var(--font-sans);
  background: var(--bg-page);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ===== 整体布局 ===== */
#app {
  display: flex;
  min-height: 100vh;
}

/* ===== 左侧导航栏 ===== */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  transition: transform 0.25s ease;
}

.sidebar.open {
  z-index: 120;
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 36, 25, 0.45);
  z-index: 110;
}
.sidebar-overlay.show { display: block; }

.sidebar-header {
  padding: 16px 18px;
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  background: var(--color-accent);
  color: var(--color-primary-dark);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  padding: 3px 7px;
  border-radius: var(--radius-sm);
  letter-spacing: -0.5px;
}

.logo-text {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}

.sidebar-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 18px;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 4px;
}

.nav-menu {
  flex: 1;
  padding: 8px 0;
  overflow-y: auto;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 18px;
  font-size: 13px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
  border-left: 3px solid transparent;
  text-decoration: none;
  position: relative;
}

.nav-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.nav-item.active {
  background: var(--color-primary-bg);
  color: var(--color-primary);
  font-weight: 600;
  border-left-color: var(--color-primary);
}

.nav-icon {
  font-size: 14px;
  width: 16px;
  text-align: center;
}

.nav-badge {
  margin-left: auto;
  background: var(--color-error);
  color: var(--text-inverse);
  font-size: 11px;
  font-weight: 700;
  padding: 1px 6px;
  border-radius: 10px;
  min-width: 18px;
  text-align: center;
}

.nav-badge:empty,
.nav-badge[data-count="0"] {
  display: none;
}

.sidebar-footer {
  padding: 12px 14px;
  border-top: 1px solid var(--border-light);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.btn-text {
  background: none;
  border: none;
  font-size: 12px;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 6px 8px;
  text-align: left;
  border-radius: var(--radius-sm);
  transition: all 0.15s;
}

.btn-text:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.btn-text.btn-danger:hover {
  background: var(--color-error-bg);
  color: var(--color-error);
}

/* ===== 手机端导航栏内工具区 ===== */
.sidebar-tools {
  display: none;
  flex-direction: column;
  gap: 10px;
  padding: 14px 16px;
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.sidebar-tools-title {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.sidebar-tools .search-box {
  max-width: 100%;
}

.sidebar-tools .search-box input {
  height: 36px;
  background: var(--bg-page);
}

.sidebar-tools .filter-select {
  height: 36px;
  background: var(--bg-page);
}

.sidebar-tools-stats {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-top: 6px;
}

.sidebar-tools-stats .streak-info,
.sidebar-tools-stats .goal-info {
  font-size: 12px;
  color: var(--text-secondary);
}

.sidebar-tools-stats .goal-progress {
  margin-top: 4px;
}

/* ===== 主区域 ===== */
.main-area {
  margin-left: var(--sidebar-width);
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* ===== 顶部工具栏 ===== */
.toolbar {
  height: var(--toolbar-height);
  background: var(--bg-toolbar);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  gap: 16px;
  position: sticky;
  top: 0;
  z-index: 110;
}

.toolbar-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 20px;
  line-height: 1;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 4px 8px 4px 0;
  flex-shrink: 0;
}

.toolbar-left {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
}

.search-box {
  position: relative;
  flex: 1;
  max-width: 360px;
}

.search-box input {
  width: 100%;
  height: 34px;
  padding: 0 12px 0 34px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 16px;
  background: var(--bg-page);
  transition: all 0.15s;
}

.search-box::before {
  content: "\1F50D";
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 13px;
  opacity: 0.5;
}

.search-box input:focus {
  outline: none;
  border-color: var(--color-primary);
  background: var(--bg-input);
  box-shadow: 0 0 0 3px rgba(31,107,67,0.1);
}

.filter-select {
  height: 34px;
  padding: 0 10px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 16px;
  background: var(--bg-page);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
}

.filter-select:hover { border-color: var(--text-tertiary); }
.filter-select:focus {
  outline: none;
  border-color: var(--color-primary);
}

.toolbar-right {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-shrink: 0;
}

.streak-info {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  color: var(--text-secondary);
}

.streak-icon { font-size: 15px; }

.goal-info {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-secondary);
}

.goal-progress {
  position: relative;
  width: 100px;
  height: 22px;
  background: var(--border-light);
  border-radius: 11px;
  overflow: hidden;
}

.goal-progress-bar {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 0%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
  border-radius: 11px;
  transition: width 0.4s ease;
}

.goal-text {
  position: relative;
  z-index: 1;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
}

/* ===== 内容包裹 ===== */
.content-wrapper {
  display: flex;
  flex: 1;
  gap: 1px;
  background: var(--border-light);
}

/* ===== 中间主内容区 ===== */
.main-content {
  flex: 1;
  padding: 20px;
  overflow-y: auto;
  background: var(--bg-content);
  min-width: 0;
}

/* ===== 右侧诊断栏 ===== */
.right-panel {
  width: var(--right-panel-width);
  background: var(--bg-card);
  padding: 16px;
  overflow-y: auto;
  flex-shrink: 0;
}

.panel-section {
  margin-bottom: 20px;
}

.panel-section:last-child { margin-bottom: 0; }

.panel-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-tertiary);
  margin-bottom: 10px;
}

/* 进度环 */
.progress-ring-container {
  position: relative;
  width: 100px;
  height: 100px;
  margin: 0 auto;
}

.progress-ring {
  transform: rotate(-90deg);
}

.progress-ring-bg {
  fill: none;
  stroke: var(--border-light);
  stroke-width: 8;
}

.progress-ring-fill {
  fill: none;
  stroke: var(--color-primary);
  stroke-width: 8;
  stroke-linecap: round;
  stroke-dasharray: 264;
  stroke-dashoffset: 264;
  transition: stroke-dashoffset 0.6s ease;
}

.progress-ring-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.progress-num {
  display: block;
  font-size: 24px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
}

.progress-label {
  font-size: 11px;
  color: var(--text-tertiary);
}

/* 统计行 */
.stat-row {
  display: flex;
  gap: 12px;
}

.stat-item {
  flex: 1;
  text-align: center;
}

.stat-value {
  display: block;
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
}

.stat-label {
  font-size: 11px;
  color: var(--text-tertiary);
}

/* 连续答对 */
.streak-counter {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-warning);
  text-align: center;
  padding: 8px 0;
}

/* 薄弱函数 */
.weak-functions {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.weak-func-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 10px;
  background: var(--color-error-bg);
  border-radius: var(--radius-sm);
  font-size: 12px;
}

.weak-func-name {
  font-weight: 600;
  color: var(--color-error);
}

.weak-func-rate {
  font-size: 11px;
  color: var(--text-secondary);
}

/* 数据统计 */
.data-stats {
  display: flex;
  gap: 8px;
}

.data-stat {
  flex: 1;
  text-align: center;
  padding: 8px 4px;
  background: var(--bg-page);
  border-radius: var(--radius-sm);
}

.data-stat-num {
  display: block;
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

.data-stat-label {
  font-size: 10px;
  color: var(--text-tertiary);
}

/* 推荐卡片 */
.recommend-card {
  background: var(--color-primary-bg);
  border-radius: var(--radius-md);
  padding: 10px 12px;
  cursor: pointer;
  transition: all 0.15s;
}

.recommend-card:hover {
  background: var(--color-primary-light);
  color: var(--text-inverse);
}

.recommend-card:hover .recommend-title,
.recommend-card:hover .recommend-meta {
  color: var(--text-inverse);
}

.recommend-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.recommend-meta {
  font-size: 11px;
  color: var(--text-secondary);
}

.empty-hint {
  font-size: 12px;
  color: var(--text-tertiary);
  text-align: center;
  padding: 8px 0;
}

/* ===== 视图通用样式 ===== */
.view-header {
  margin-bottom: 20px;
}

.view-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.view-subtitle {
  font-size: 13px;
  color: var(--text-secondary);
}

/* ===== 总览工作台 ===== */
.overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.overview-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  transition: all 0.15s;
}

.overview-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.overview-card-label {
  font-size: 12px;
  color: var(--text-tertiary);
  margin-bottom: 8px;
}

.overview-card-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-primary);
}

.overview-card-trend {
  font-size: 12px;
  color: var(--color-success);
  margin-top: 4px;
}

.overview-card-icon {
  float: right;
  font-size: 28px;
  opacity: 0.15;
}

/* 学习路径卡片 */
.section-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.path-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}

.path-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 18px;
  cursor: pointer;
  transition: all 0.2s;
}

.path-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
}

.path-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.path-card-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
}

.path-card-progress {
  font-size: 12px;
  color: var(--color-primary);
  font-weight: 600;
}

.path-progress-bar {
  width: 100%;
  height: 6px;
  background: var(--border-light);
  border-radius: 3px;
  margin-bottom: 10px;
  overflow: hidden;
}

.path-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
  border-radius: 3px;
  transition: width 0.4s ease;
}

.path-card-desc {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.path-card-functions {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 10px;
}

.path-func-tag {
  font-size: 11px;
  font-family: var(--font-mono);
  padding: 2px 8px;
  background: var(--bg-page);
  border-radius: 3px;
  color: var(--text-secondary);
}

.path-func-tag.done {
  background: var(--color-success-bg);
  color: var(--color-success);
}

/* ===== 函数分类页 ===== */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 18px;
  cursor: pointer;
  transition: all 0.2s;
}

.category-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
}

.category-card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.category-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.category-name {
  font-size: 15px;
  font-weight: 600;
}

.category-count {
  font-size: 12px;
  color: var(--text-tertiary);
}

.category-functions {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 8px;
}

/* 函数知识库弹窗 */
.func-modal {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
}

.func-modal h2 {
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--color-primary);
  margin-bottom: 4px;
}

.func-modal .func-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.func-modal .func-section {
  margin-bottom: 14px;
}

.func-modal .func-section-title {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-tertiary);
  margin-bottom: 6px;
}

.func-modal .func-syntax {
  font-family: var(--font-mono);
  font-size: 13px;
  background: var(--bg-page);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-primary);
}

.func-modal .func-example {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-primary);
  background: var(--color-primary-bg);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
}

/* ===== 题库列表 ===== */
.question-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.question-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  cursor: pointer;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  gap: 12px;
}

.question-item:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.question-item.done {
  border-left: 3px solid var(--color-success);
}

.question-item.error {
  border-left: 3px solid var(--color-error);
}

.question-item.favorited .q-fav-icon {
  color: var(--color-warning);
}

.q-id {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
  min-width: 50px;
}

.q-title {
  flex: 1;
  font-size: 13px;
  color: var(--text-primary);
}

.q-tags {
  display: flex;
  gap: 6px;
  align-items: center;
}

.q-fav-icon {
  font-size: 14px;
  color: var(--border-color);
}

/* 难度标签 */
.diff-badge {
  font-size: 10px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 10px;
  text-transform: uppercase;
}

.diff-1 { background: #E0F2FE; color: #0284C7; }
.diff-2 { background: #DCFCE7; color: #16A34A; }
.diff-3 { background: #FEF3C7; color: #D97706; }
.diff-4 { background: #FED7AA; color: #EA580C; }
.diff-5 { background: #FEE2E2; color: #DC2626; }

/* 函数标签 */
.func-tag {
  font-size: 11px;
  font-family: var(--font-mono);
  padding: 1px 7px;
  border-radius: 3px;
  background: var(--color-primary-bg);
  color: var(--color-primary);
}

.func-tag-sm {
  font-size: 10px;
  font-family: var(--font-mono);
  padding: 1px 5px;
  border-radius: 3px;
  background: var(--bg-page);
  color: var(--text-secondary);
}

/* 分类标签 */
.cat-tag {
  font-size: 11px;
  padding: 1px 7px;
  border-radius: 3px;
  background: var(--color-blue-light);
  color: var(--color-blue);
}

/* ===== 练习区 ===== */
.practice-container {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.practice-header {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.practice-header-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}

.practice-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
}

.practice-tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  align-items: center;
}

.practice-actions {
  display: flex;
  gap: 6px;
}

.btn-icon {
  width: 34px;
  height: 34px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-card);
  cursor: pointer;
  font-size: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s;
  color: var(--text-secondary);
}

.btn-icon:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-icon.active {
  background: var(--color-warning-bg);
  border-color: var(--color-warning);
  color: var(--color-warning);
}

.practice-scenario {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  padding: 10px 14px;
  background: var(--bg-page);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--color-blue);
}

.practice-prompt {
  font-size: 13px;
  color: var(--text-primary);
  margin-top: 10px;
  font-weight: 500;
}

.practice-prompt .target-cell {
  font-family: var(--font-mono);
  background: var(--color-primary-bg);
  color: var(--color-primary);
  padding: 1px 6px;
  border-radius: 3px;
  font-weight: 600;
}

/* ===== Excel 表格 ===== */
.table-wrapper {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.table-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 14px;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-table-header);
}

.table-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}

.table-scroll {
  overflow-x: auto;
}

.excel-table {
  border-collapse: collapse;
  font-size: 13px;
  white-space: nowrap;
}

.excel-table th,
.excel-table td {
  border: 1px solid var(--border-table);
  padding: 6px 12px;
  text-align: left;
}

.excel-table th {
  background: var(--bg-table-header);
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 12px;
  min-width: 80px;
}

.excel-table .row-num {
  background: var(--bg-table-header);
  color: var(--text-tertiary);
  font-size: 11px;
  text-align: center;
  min-width: 40px;
  width: 40px;
  padding: 6px 4px;
}

.excel-table tbody tr:nth-child(even) {
  background: var(--bg-table-row-alt);
}

.excel-table .cell-target {
  background: var(--color-primary-bg) !important;
  font-weight: 600;
  color: var(--color-primary);
  position: relative;
}

.excel-table .cell-target::after {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  border: 2px solid var(--color-primary);
  pointer-events: none;
}

/* ===== 公式输入区 ===== */
.formula-section {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 16px;
}

/* ===== 公式快捷键栏 ===== */
.formula-shortcuts {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 10px;
  margin-bottom: 12px;
}
.sc-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}
.sc-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-tertiary);
  margin-right: 2px;
}
.sc-key,
.sc-fn {
  border: 1px solid var(--border-color);
  background: var(--bg-input);
  border-radius: 8px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1;
  color: var(--text-primary);
  padding: 7px 10px;
  transition: background .12s, border-color .12s, transform .05s;
  user-select: none;
}
.sc-fn {
  color: var(--color-primary);
  font-weight: 600;
}
.sc-key:hover,
.sc-fn:hover {
  background: var(--color-primary-bg);
  border-color: var(--color-primary-light);
}
.sc-key:active,
.sc-fn:active {
  transform: scale(.95);
}

.formula-bar {
  display: flex;
  align-items: center;
  gap: 0;
  border: 1px solid var(--border-table);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--bg-input);
}

.formula-bar-prefix {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 0 12px;
  height: 40px;
  background: var(--bg-table-header);
  border-right: 1px solid var(--border-table);
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--color-primary);
  font-weight: 600;
  flex-shrink: 0;
}

.formula-cell-ref {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-secondary);
}

.formula-input {
  flex: 1;
  border: none;
  outline: none;
  height: 40px;
  padding: 0 12px;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--text-primary);
  background: transparent;
}

.formula-input::placeholder {
  color: var(--text-tertiary);
}

.formula-input:focus {
  background: rgba(31,107,67,0.03);
}

.formula-actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
  align-items: center;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--text-inverse);
  border: none;
  border-radius: var(--radius-md);
  padding: 8px 20px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-primary:hover {
  background: var(--color-primary-dark);
}

.btn-primary:active {
  transform: scale(0.98);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 8px 16px;
  font-size: 13px;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-secondary:hover {
  border-color: var(--text-tertiary);
  color: var(--text-primary);
}

.btn-hint {
  background: var(--color-warning-bg);
  color: var(--color-warning);
  border: 1px solid transparent;
}

.btn-hint:hover {
  background: var(--color-warning);
  color: var(--text-inverse);
}

.btn-next {
  background: var(--color-blue);
  color: var(--text-inverse);
}

.btn-next:hover {
  background: #1D4ED8;
}

.formula-shortcut {
  margin-left: auto;
  font-size: 11px;
  color: var(--text-tertiary);
}

.kbd {
  display: inline-block;
  padding: 1px 5px;
  font-family: var(--font-mono);
  font-size: 11px;
  background: var(--bg-page);
  border: 1px solid var(--border-color);
  border-radius: 3px;
  color: var(--text-secondary);
}

/* ===== 答题反馈 ===== */
.feedback-area {
  border-radius: var(--radius-lg);
  padding: 14px 16px;
  font-size: 13px;
  display: none;
  animation: slideIn 0.3s ease;
}

.feedback-area.show { display: block; }

.feedback-correct {
  background: var(--color-success-bg);
  border: 1px solid var(--color-success);
  color: var(--color-success);
}

.feedback-wrong {
  background: var(--color-error-bg);
  border: 1px solid var(--color-error);
  color: var(--color-error);
}

.feedback-hint {
  background: var(--color-warning-bg);
  border: 1px solid var(--color-warning);
  color: var(--color-warning);
}

.feedback-title {
  font-weight: 700;
  font-size: 14px;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.feedback-detail {
  color: var(--text-primary);
  font-size: 13px;
  margin-top: 6px;
}

.feedback-detail code {
  font-family: var(--font-mono);
  font-size: 12px;
  background: rgba(0,0,0,0.06);
  padding: 1px 6px;
  border-radius: 3px;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes correctPulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.02); }
  100% { transform: scale(1); }
}

.feedback-correct.show {
  animation: slideIn 0.3s ease, correctPulse 0.4s ease 0.3s;
}

/* ===== 提示区域 ===== */
.hints-area {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 16px;
  display: none;
}

.hints-area.show { display: block; }

.hint-item {
  padding: 8px 12px;
  background: var(--color-warning-bg);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text-primary);
  margin-bottom: 6px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  animation: slideIn 0.3s ease;
}

.hint-number {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--color-warning);
  color: var(--text-inverse);
  font-size: 11px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hint-answer {
  margin-top: 4px;
  padding: 12px 14px;
  background: var(--color-primary-bg);
  border: 1px solid var(--color-primary-light);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-sm);
  font-size: 13px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  animation: slideIn 0.3s ease;
}

.hint-answer-label {
  flex-shrink: 0;
  font-weight: 700;
  color: var(--color-primary);
}

.hint-answer-value code {
  background: rgba(255,255,255,.7);
  border: 1px solid var(--color-primary-light);
  border-radius: 5px;
  padding: 2px 7px;
  font-family: var(--font-mono);
  color: var(--color-primary-dark);
  font-size: 12.5px;
}

/* ===== 解析区域 ===== */
.explanation-area {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: none;
}

.explanation-area.show { display: block; }

.explanation-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.explanation-content {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.explanation-content code {
  font-family: var(--font-mono);
  font-size: 12px;
  background: var(--color-primary-bg);
  color: var(--color-primary);
  padding: 2px 8px;
  border-radius: 3px;
  font-weight: 500;
}

.concepts-area {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 16px;
}

.concept-tag {
  font-size: 12px;
  padding: 3px 10px;
  background: var(--color-info-bg);
  color: var(--color-info);
  border-radius: 12px;
}

.similar-questions {
  border-top: 1px solid var(--border-light);
  padding-top: 14px;
}

.similar-title {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-tertiary);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.similar-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.15s;
  margin-bottom: 6px;
}

.similar-item:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-bg);
}

.similar-item-id {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-tertiary);
}

.similar-item-title {
  font-size: 13px;
  color: var(--text-primary);
}

/* ===== 空状态 ===== */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-tertiary);
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.3;
}

.empty-state-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.empty-state-desc {
  font-size: 13px;
}

/* ===== 能力诊断页 ===== */
.diagnosis-section {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 16px;
}

.diagnosis-section-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 16px;
}

.mastery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}

.mastery-item {
  background: var(--bg-page);
  border-radius: var(--radius-md);
  padding: 12px;
}

.mastery-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.mastery-name {
  font-size: 13px;
  font-weight: 600;
}

.mastery-rate {
  font-size: 12px;
  color: var(--text-secondary);
}

.mastery-bar {
  width: 100%;
  height: 6px;
  background: var(--border-light);
  border-radius: 3px;
  overflow: hidden;
}

.mastery-bar-fill {
  height: 100%;
  border-radius: 3px;
  transition: width 0.6s ease;
}

.error-type-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.error-type-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 12px;
  background: var(--bg-page);
  border-radius: var(--radius-md);
}

.error-type-name {
  flex: 1;
  font-size: 13px;
}

.error-type-count {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-error);
}

.error-type-bar {
  width: 80px;
  height: 6px;
  background: var(--border-light);
  border-radius: 3px;
  overflow: hidden;
}

.error-type-bar-fill {
  height: 100%;
  background: var(--color-error);
  border-radius: 3px;
}

/* ===== 学习路径详情 ===== */
.path-detail {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.path-step {
  display: flex;
  align-items: center;
  gap: 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  cursor: pointer;
  transition: all 0.15s;
}

.path-step:hover {
  border-color: var(--color-primary);
}

.path-step-num {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  flex-shrink: 0;
  background: var(--bg-page);
  color: var(--text-tertiary);
}

.path-step.done .path-step-num {
  background: var(--color-success);
  color: var(--text-inverse);
}

.path-step-content {
  flex: 1;
}

.path-step-name {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}

.path-step-desc {
  font-size: 12px;
  color: var(--text-secondary);
}

.path-step-arrow {
  color: var(--text-tertiary);
}

/* ===== 自动补全下拉 ===== */
.autocomplete-dropdown {
  position: fixed;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 200px;
  overflow-y: auto;
  z-index: 200;
  display: none;
}

.autocomplete-dropdown.show { display: block; }

.autocomplete-item {
  padding: 6px 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  cursor: pointer;
  transition: background 0.1s;
}

.autocomplete-item:hover,
.autocomplete-item.selected {
  background: var(--color-primary-bg);
  color: var(--color-primary);
}

.autocomplete-item-desc {
  font-family: var(--font-sans);
  font-size: 11px;
  color: var(--text-tertiary);
  margin-left: 8px;
}

/* ===== Toast 通知 ===== */
.toast-container {
  position: fixed;
  top: 70px;
  right: 20px;
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px 16px;
  font-size: 13px;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.3s ease;
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 200px;
}

.toast.success { border-left: 3px solid var(--color-success); }
.toast.error { border-left: 3px solid var(--color-error); }
.toast.info { border-left: 3px solid var(--color-blue); }
.toast.warning { border-left: 3px solid var(--color-warning); }

@keyframes toastIn {
  from { opacity: 0; transform: translateX(20px); }
  to { opacity: 1; transform: translateX(0); }
}

/* ===== Modal 对话框 ===== */
.modal-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.4);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 500;
}

.modal-overlay.show { display: flex; }

.modal-dialog {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  max-width: 420px;
  width: 90%;
  box-shadow: var(--shadow-lg);
}

.modal-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.modal-message {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

/* ===== 分页 ===== */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-top: 20px;
}

.page-btn {
  width: 32px;
  height: 32px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  cursor: pointer;
  font-size: 13px;
  color: var(--text-secondary);
  transition: all 0.15s;
}

.page-btn:hover { border-color: var(--color-primary); }
.page-btn.active {
  background: var(--color-primary);
  color: var(--text-inverse);
  border-color: var(--color-primary);
}

.page-info {
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .right-panel {
    display: none;
  }
}

@media (max-width: 768px) {
  :root {
    --sidebar-width: 200px;
  }

  .sidebar {
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
  }

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

  .sidebar-toggle {
    display: block;
  }

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

  .main-area {
    margin-left: 0;
  }

  .toolbar {
    flex-wrap: wrap;
    height: 56px;
    padding: 0 12px;
    gap: 8px;
    justify-content: flex-start;
  }

  .toolbar-left,
  .toolbar-right,
  .toolbar .search-box,
  .toolbar .filter-select {
    display: none !important;
  }

  .sidebar-tools {
    display: flex;
  }

  .main-content {
    padding: 12px;
  }

  .practice-header-top {
    flex-direction: column;
  }

  .practice-actions {
    align-self: flex-end;
  }

  .table-scroll {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .formula-actions {
    flex-wrap: wrap;
  }

  .formula-shortcut {
    display: none;
  }

  .overview-grid {
    grid-template-columns: 1fr 1fr;
    gap: 10px;
  }

  .overview-card {
    padding: 14px;
  }

  .overview-card-value {
    font-size: 22px;
  }

  .overview-card-label {
    font-size: 12px;
  }

  .overview-card-icon {
    font-size: 18px;
  }

  .overview-card-trend {
    font-size: 11px;
  }

  .path-cards,
  .category-grid {
    grid-template-columns: 1fr;
  }

  .btn-primary,
  .btn-secondary {
    flex: 1;
    text-align: center;
    justify-content: center;
  }
}

@media (max-width: 484px) {
  .overview-grid {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  .overview-card {
    padding: 12px;
  }

  .overview-card-value {
    font-size: 20px;
  }

  .practice-title {
    font-size: 16px;
  }

  .data-stats {
    flex-direction: column;
  }
}

/* ===== 滚动条美化 ===== */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

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

/* ===== 选中文字 ===== */
::selection {
  background: var(--color-primary-bg);
  color: var(--color-primary);
}

/* ===== 登录页（密码网关） ===== */
body.locked #app { display: none !important; }
body.locked .sidebar-overlay,
body.locked .autocomplete-dropdown,
body.locked .toast-container,
body.locked .modal-overlay { display: none !important; }

.login-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background:
    radial-gradient(120% 80% at 85% -10%, rgba(42,132,87,.10), transparent 55%),
    linear-gradient(180deg, #f5faf7 0%, #eef6f0 100%);
}

body.locked .login-overlay { display: flex; }

.login-card {
  width: 100%;
  max-width: 360px;
  background: #fff;
  border: 1px solid var(--border-color);
  border-radius: 18px;
  padding: 38px 32px 28px;
  box-shadow: 0 18px 50px rgba(15,36,25,.10);
  text-align: center;
}

.login-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 22px;
}

.fx-mark {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: linear-gradient(135deg, #ffd766, #f5a623);
  color: #0f2419;
  font-style: italic;
  font-weight: 800;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
}

.login-title {
  font-size: 24px;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.login-sub {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 8px;
  margin-bottom: 26px;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.login-input {
  width: 100%;
  padding: 13px 15px;
  font-size: 16px;
  border: 1.5px solid var(--border-color);
  border-radius: 11px;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}

.login-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(31,107,67,.12);
}

.login-btn {
  width: 100%;
  padding: 13px;
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  background: var(--color-primary);
  border: none;
  border-radius: 11px;
  cursor: pointer;
  transition: background .15s, transform .05s;
}

.login-btn:hover { background: var(--color-primary-light); }
.login-btn:active { transform: scale(.99); }

.login-error {
  min-height: 18px;
  margin: 12px 0 0;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-error);
}

.login-hint {
  margin-top: 14px;
  font-size: 12px;
  color: var(--text-tertiary);
}