:root {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-card-hover: #ffffff;
  --glass-border: #e2e8f0;
  --glass-border-focus: #3b82f6;
  
  --primary: #2563eb;
  --primary-light: #3b82f6;
  --primary-dark: #1d4ed8;
  --primary-glow: rgba(37, 99, 235, 0.18);
  
  --accent: #06b6d4;
  --accent-cyan: #0284c7;
  --success: #10b981;
  --success-glow: rgba(16, 185, 129, 0.2);
  --warning: #f59e0b;
  --danger: #ef4444;
  --danger-glow: rgba(239, 68, 68, 0.2);

  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 16px -2px rgba(15, 23, 42, 0.08), 0 2px 6px -1px rgba(15, 23, 42, 0.04);
  --shadow-glow: 0 0 20px rgba(79, 70, 229, 0.15);
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

body {
  font-family: var(--font-family);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  background-image: 
    radial-gradient(at 0% 0%, rgba(99, 102, 241, 0.06) 0px, transparent 50%),
    radial-gradient(at 100% 0%, rgba(139, 92, 246, 0.06) 0px, transparent 50%),
    radial-gradient(at 50% 100%, rgba(2, 132, 199, 0.04) 0px, transparent 50%);
  background-attachment: fixed;
}

/* 滚动条美化 */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--primary);
}

/* 应用主布局 */
#app-layout {
  display: flex;
  min-height: 100vh;
}

/* 侧边导航栏 */
.sidebar {
  width: 260px;
  background: #ffffff;
  border-right: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 2px 0 10px rgba(0, 0, 0, 0.02);
  z-index: 50;
}

.brand-header {
  padding: 24px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--glass-border);
}

.brand-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  box-shadow: var(--shadow-glow);
  color: #fff;
}

.brand-text h1 {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.brand-text span {
  font-size: 11px;
  color: var(--text-muted);
  display: block;
}

.nav-group {
  padding: 16px 12px;
  flex: 1;
  overflow-y: auto;
}

.nav-title {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  padding: 8px 12px;
  font-weight: 600;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  margin-bottom: 4px;
}

.nav-item:hover {
  color: var(--primary);
  background: #f1f5f9;
}

.nav-item.active {
  color: var(--primary);
  background: #eef2ff;
  border-left: 3px solid var(--primary);
  font-weight: 600;
}

.nav-item .icon {
  font-size: 18px;
}

.nav-badge {
  margin-left: auto;
  font-size: 11px;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  background: var(--primary-dark);
  color: #fff;
}

.sidebar-footer {
  padding: 16px;
  border-top: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  gap: 12px;
  background: #f8fafc;
}

.user-avatar {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, #4f46e5, #06b6d4);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 14px;
  color: #fff;
  border: 2px solid var(--glass-border);
}

.user-info {
  flex: 1;
  overflow: hidden;
}

.user-info .name {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.user-info .role {
  font-size: 11px;
  color: var(--primary);
  font-weight: 500;
}

.logout-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 16px;
  padding: 6px;
  border-radius: var(--radius-sm);
  transition: all 0.2s;
}

.logout-btn:hover {
  color: var(--danger);
  background: rgba(239, 68, 68, 0.1);
}

/* 主内容容器 */
.main-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--bg-primary);
}

/* 顶部顶栏 */
.topbar {
  height: 64px;
  border-bottom: 1px solid var(--glass-border);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  position: sticky;
  top: 0;
  z-index: 40;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

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

.role-pill {
  font-size: 12px;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: rgba(99, 102, 241, 0.15);
  color: var(--primary-light);
  border: 1px solid rgba(99, 102, 241, 0.3);
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.quick-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.admin-btn-text {
  display: inline;
}
.admin-btn-short-text {
  display: none;
}
.admin-view-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 22px;
  gap: 16px;
}
.dashboard-split-grid {
  display: grid;
  grid-template-columns: 2fr 1.2fr;
  gap: 24px;
}

/* 按钮规范 (专业、协调的企业级现代 SaaS 风格) */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  line-height: 1.4;
}

.btn-primary {
  background: #2563eb;
  color: #ffffff;
  border: 1px solid #1d4ed8;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05), 0 2px 4px rgba(37, 99, 235, 0.12);
}
.btn-primary:hover {
  background: #1d4ed8;
  border-color: #1e40af;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.22);
}
.btn-primary:active {
  background: #1e40af;
  transform: translateY(0);
}

.btn-secondary {
  background: #ffffff;
  color: #334155;
  border: 1px solid #cbd5e1;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}
.btn-secondary:hover {
  background: #f8fafc;
  color: #0f172a;
  border-color: #94a3b8;
  transform: translateY(-1px);
}
.btn-secondary:active {
  background: #f1f5f9;
  transform: translateY(0);
}

.btn-dark {
  background: #0f172a;
  color: #ffffff;
  border: 1px solid #1e293b;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}
.btn-dark:hover {
  background: #1e293b;
  border-color: #334155;
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.15);
}
.btn-dark:active {
  background: #020617;
  transform: translateY(0);
}

.btn-success {
  background: #10b981;
  color: #ffffff;
  border: 1px solid #059669;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}
.btn-success:hover {
  background: #059669;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.2);
}

.btn-danger {
  background: #fef2f2;
  color: #ef4444;
  border: 1px solid #fecaca;
}
.btn-danger:hover {
  background: #fee2e2;
  border-color: #fca5a5;
  transform: translateY(-1px);
}

.btn-warning {
  background: #f59e0b;
  color: #ffffff;
  border: 1px solid #d97706;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}
.btn-warning:hover {
  background: #d97706;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(245, 158, 11, 0.2);
}

.btn-sm {
  padding: 6px 14px;
  font-size: 12px;
  border-radius: var(--radius-sm);
}

/* 分段选择器控件 (Segmented Control，常用于身份切换、视图切换) */
.segmented-group {
  display: inline-flex;
  align-items: center;
  background: #f1f5f9;
  padding: 3px;
  border-radius: var(--radius-full);
  border: 1px solid #e2e8f0;
  gap: 2px;
}
.segmented-item {
  border: none;
  background: transparent;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 500;
  color: #64748b;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  text-decoration: none;
  line-height: 1.4;
}
.segmented-item:hover {
  color: #0f172a;
}
.segmented-item.active {
  background: #ffffff;
  color: #0f172a;
  font-weight: 600;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.08);
}

/* 标签筛选组控件 (Filter Tabs Group) */
.filter-tabs-group {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #f8fafc;
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid #e2e8f0;
}
.filter-tab {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 500;
  color: #64748b;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  background: transparent;
  cursor: pointer;
  transition: all 0.15s ease;
}
.filter-tab:hover {
  color: #0f172a;
  background: #f1f5f9;
}
.filter-tab.active {
  background: #ffffff;
  color: #0f172a;
  font-weight: 600;
  border-color: #e2e8f0;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.06);
}

/* 内容主区域 */
.content-area {
  flex: 1;
  padding: 28px;
  overflow-y: auto;
}

/* 统计卡片网格 */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-bottom: 28px;
}

.stat-card {
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 2px 8px -2px rgba(15, 23, 42, 0.06);
  transition: all 0.3s;
}

.stat-card:hover {
  border-color: var(--primary-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 16px -4px rgba(79, 70, 229, 0.12);
}

.stat-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.stat-title {
  font-size: 13px;
  color: var(--text-secondary);
  font-weight: 500;
}

.stat-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  background: #f1f5f9;
  border: 1px solid #e2e8f0;
}

.stat-val {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.stat-change {
  font-size: 12px;
  color: var(--success);
  display: flex;
  align-items: center;
  gap: 4px;
}

/* 面板/卡片通用 */
.panel {
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  margin-bottom: 24px;
  overflow: hidden;
  box-shadow: 0 2px 8px -2px rgba(15, 23, 42, 0.05);
}

.panel-header {
  padding: 18px 24px;
  background: #ffffff;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.panel-title {
  font-size: 15px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
}

.panel-body {
  padding: 24px;
}

/* 表格规范 */
.custom-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 13px;
}

.custom-table th {
  padding: 12px 16px;
  background: #f8fafc;
  color: var(--text-secondary);
  font-weight: 600;
  border-bottom: 1px solid var(--glass-border);
}

.custom-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--glass-border);
  color: var(--text-primary);
  vertical-align: middle;
}

.custom-table tbody tr {
  transition: background 0.15s;
}

.custom-table tbody tr:hover {
  background: #f8fafc;
}

/* 课程网格 */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.course-card {
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all 0.25s;
  display: flex;
  flex-direction: column;
  box-shadow: 0 2px 8px -2px rgba(15, 23, 42, 0.05);
}

.course-card:hover {
  border-color: var(--primary-light);
  transform: translateY(-3px);
  box-shadow: 0 12px 20px -4px rgba(79, 70, 229, 0.12), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
}

.course-banner {
  height: 140px;
  background: linear-gradient(135deg, #e0e7ff, #ede9fe);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 42px;
}

.course-category-tag {
  position: absolute;
  top: 12px;
  left: 12px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(4px);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  font-size: 11px;
  font-weight: 600;
  color: #4338ca;
  border: 1px solid #c7d2fe;
}

.course-content {
  padding: 18px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.course-name {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.course-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
  flex: 1;
}

.course-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 12px;
  border-top: 1px solid var(--glass-border);
  font-size: 12px;
  color: var(--text-muted);
}

/* 标签 Tag */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 600;
}
.badge-success { background: #ecfdf5; color: #059669; border: 1px solid #a7f3d0; }
.badge-warning { background: #fffbeb; color: #d97706; border: 1px solid #fde68a; }
.badge-info { background: #f0f9ff; color: #0284c7; border: 1px solid #bae6fd; }
.badge-danger { background: #fef2f2; color: #dc2626; border: 1px solid #fecaca; }
.badge-secondary { background: #f1f5f9; color: #475569; border: 1px solid #e2e8f0; }

/* 模态框 Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(15, 23, 42, 0.45);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-box {
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  width: 90%;
  max-width: 520px;
  box-shadow: 0 25px 50px -12px rgba(15, 23, 42, 0.18);
  transform: translateY(20px) scale(0.98);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
}

.modal-overlay.active .modal-box {
  transform: translateY(0) scale(1);
}

.modal-header {
  padding: 18px 24px;
  background: #ffffff;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-header h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
}

.modal-body {
  padding: 24px;
  max-height: 70vh;
  overflow-y: auto;
  color: var(--text-primary);
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--glass-border);
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  background: #f8fafc;
}

/* 表单控件 */
.form-group {
  margin-bottom: 18px;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 10px 14px;
  background: #ffffff;
  border: 1px solid #cbd5e1;
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 13px;
  transition: all 0.2s;
  outline: none;
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

/* 登录/全屏页面 */
.auth-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 20px;
}

.auth-card {
  width: 100%;
  max-width: 440px;
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 36px;
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
}

.auth-header {
  text-align: center;
  margin-bottom: 28px;
}

.auth-header h2 {
  font-size: 24px;
  font-weight: 700;
  margin-top: 12px;
  color: var(--text-primary);
}

.auth-header p {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 4px;
}

.quick-login-pills {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
}

.quick-pill {
  flex: 1;
  padding: 8px;
  font-size: 12px;
  border-radius: var(--radius-md);
  background: #f8fafc;
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
  cursor: pointer;
  text-align: center;
  transition: all 0.2s;
}

.quick-pill:hover, .quick-pill.active {
  background: #eef2ff;
  border-color: var(--primary);
  color: var(--primary);
  font-weight: 600;
}

/* 直播研训大厅头部横幅 (纯流式企业级排版，严禁使用任何绝对定位) */
.live-hall-hero {
  background: linear-gradient(135deg, #f0fdf4 0%, #eff6ff 50%, #faf5ff 100%);
  border: 1px solid #e0e7ff;
  border-radius: var(--radius-xl);
  padding: 30px;
  color: #0f172a;
  margin-bottom: 28px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 20px -2px rgba(99, 102, 241, 0.08);
}
.live-hero-bg-icon {
  position: absolute;
  right: 20px;
  top: 10px;
  font-size: 140px;
  opacity: 0.05;
  pointer-events: none;
}
.live-hero-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}
.live-status-pill-wrap {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #ffffff;
  border: 1px solid #fecaca;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 12px;
  color: #dc2626;
  font-weight: 600;
}
.live-hall-title {
  font-size: 26px;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 10px;
  line-height: 1.3;
  position: relative;
  z-index: 1;
}
.live-hall-desc {
  font-size: 14px;
  color: #475569;
  line-height: 1.6;
  margin-bottom: 20px;
  max-width: 720px;
  position: relative;
  z-index: 1;
}
.live-hero-bottom-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  position: relative;
  z-index: 1;
}
.live-quick-enter-box {
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 480px;
  background: #ffffff;
  padding: 5px 6px 5px 12px;
  border-radius: var(--radius-lg);
  border: 1px solid #cbd5e1;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
  box-sizing: border-box;
}
.live-room-input {
  flex: 1 1 auto;
  min-width: 0;
  background: transparent;
  border: none;
  padding: 8px 6px;
  color: #0f172a;
  font-size: 14px;
  outline: none;
}
.live-enter-btn {
  padding: 9px 20px;
  font-weight: 600;
  border-radius: var(--radius-md);
  white-space: nowrap;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.live-create-btn {
  padding: 8px 18px;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-full);
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.live-teacher-desktop-wrap {
  display: block;
}
.live-teacher-mobile-wrap {
  display: none;
}
.live-create-btn-mobile {
  width: 100%;
  padding: 10px 16px;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

/* 直播教室布局 */
.live-container {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 20px;
  height: calc(100vh - 130px);
}

.video-player-box {
  background: #000;
  border-radius: var(--radius-lg);
  border: 1px solid var(--glass-border);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  position: relative;
}

.video-screen {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at center, #1e1b4b, #000);
  overflow: hidden;
}

.video-screen video, .video-screen img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-controls {
  padding: 14px 20px;
  background: rgba(17, 24, 39, 0.9);
  border-top: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.chat-panel {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.chat-messages {
  flex: 1;
  padding: 16px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.chat-msg-item {
  font-size: 13px;
  line-height: 1.4;
}

.chat-sender {
  font-weight: 600;
  color: var(--primary-light);
  margin-right: 6px;
}

.chat-input-bar {
  padding: 12px;
  border-top: 1px solid var(--glass-border);
  display: flex;
  gap: 8px;
}

/* Toast 提示框 */
#toast-container {
  position: fixed;
  top: 24px;
  right: 24px;
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.toast {
  padding: 12px 18px;
  border-radius: var(--radius-md);
  font-size: 13px;
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.4);
  animation: slideIn 0.3s ease forwards;
  backdrop-filter: blur(8px);
}

.toast-success { background: rgba(16, 185, 129, 0.9); color: #fff; }
.toast-error { background: rgba(239, 68, 68, 0.9); color: #fff; }
.toast-info { background: rgba(99, 102, 241, 0.9); color: #fff; }

@keyframes slideIn {
  from { opacity: 0; transform: translateX(50px); }
  to { opacity: 1; transform: translateX(0); }
}

/* ============================================================= */
/* 前台学员门户端 (Client Student Portal) 专属高端样式 */
/* ============================================================= */
.portal-layout {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.portal-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  padding: 0 28px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: all 0.2s ease;
}

.portal-nav-brand {
  display: flex;
  align-items: center;
}

.portal-brand-logo {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  box-shadow: 0 0 15px var(--primary-glow);
  color: #fff;
  flex-shrink: 0;
}

.portal-brand-text {
  display: flex;
  flex-direction: column;
}

.portal-brand-title {
  font-size: 17px;
  font-weight: 700;
  color: #0f172a;
  letter-spacing: -0.5px;
  line-height: 1.2;
}

.portal-brand-sub {
  font-size: 11px;
  color: var(--text-muted);
  line-height: 1.2;
}

.portal-nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.portal-nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.portal-nav-item {
  color: #475569;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: var(--radius-full);
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 6px;
  border: 1px solid transparent;
}

.portal-nav-item:hover, .portal-nav-item.active {
  color: var(--primary);
  background: #eff6ff;
  border-color: #bfdbfe;
  font-weight: 600;
}

/* 移动端专属底部 TabBar（桌面端默认彻底隐藏） */
.portal-mobile-tabbar {
  display: none;
}

/* 演示切号助手悬浮挂件 */
.demo-assistant-widget-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 99999;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  transition: all 0.2s ease;
}

.demo-assistant-trigger-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  background: #0f172a;
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 20px;
  padding: 7px 14px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.25);
  transition: all 0.2s ease;
}

.demo-assistant-trigger-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(15, 23, 42, 0.35);
}

.portal-hero {
  position: relative;
  padding: 60px 24px 50px;
  text-align: center;
  background: linear-gradient(180deg, #eff6ff 0%, #f8fafc 100%);
  border-bottom: 1px solid var(--glass-border);
}

.portal-hero h1 {
  font-size: 38px;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 14px;
  letter-spacing: -0.5px;
}

.portal-hero-actions {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
}

.portal-hero p {
  font-size: 16px;
  color: #475569;
  max-width: 680px;
  margin: 0 auto 28px;
  line-height: 1.6;
}

.portal-stats-row {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-top: 24px;
  flex-wrap: wrap;
}

.portal-stat-chip {
  background: #ffffff;
  border: 1px solid var(--glass-border);
  padding: 8px 18px;
  border-radius: var(--radius-full);
  font-size: 13px;
  color: #1e293b;
  display: flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.portal-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 36px 24px 60px;
  width: 100%;
  flex: 1;
}

.portal-category-pills {
  display: flex;
  gap: 10px;
  margin-bottom: 30px;
  overflow-x: auto;
  padding-bottom: 6px;
}

.category-pill {
  padding: 8px 20px;
  border-radius: var(--radius-full);
  background: #ffffff;
  border: 1px solid #cbd5e1;
  color: #475569;
  font-size: 13px;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s;
}

.category-pill:hover {
  background: #f8fafc;
  color: #0f172a;
  border-color: #94a3b8;
}

.category-pill.active {
  background: #0f172a;
  color: #ffffff;
  border-color: #0f172a;
  box-shadow: 0 2px 8px rgba(15, 23, 42, 0.12);
}

.portal-footer {
  background: #f8fafc;
  border-top: 1px solid var(--glass-border);
  padding: 36px 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
  margin-top: auto;
}

/* -------------------------------------------------------------
   精品录播与影院播放器视窗 (Cinema Mode)
   ------------------------------------------------------------- */
.cinema-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.65);
  backdrop-filter: blur(12px);
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  animation: fadeIn 0.25s ease-out;
}

.cinema-modal {
  width: 95vw;
  max-width: 1400px;
  height: 90vh;
  max-height: 900px;
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  box-shadow: 0 25px 50px -12px rgba(15, 23, 42, 0.25);
  overflow: hidden;
}

.cinema-header {
  padding: 16px 24px;
  background: #ffffff;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.cinema-header h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.cinema-body {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 380px;
  overflow: hidden;
}

.cinema-main {
  background: #000;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.cinema-video-wrap {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #000;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.cinema-video-wrap video {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.cinema-control-bar {
  padding: 14px 20px;
  background: #f8fafc;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.speed-selector {
  display: flex;
  gap: 6px;
  align-items: center;
}

.speed-btn {
  padding: 4px 10px;
  font-size: 12px;
  border-radius: var(--radius-md);
  border: 1px solid #cbd5e1;
  background: #ffffff;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.speed-btn:hover, .speed-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.cinema-details {
  padding: 20px 24px;
  background: #ffffff;
  flex: 1;
  color: var(--text-primary);
}

.cinema-sidebar {
  background: #f8fafc;
  border-left: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.cinema-sidebar-header {
  padding: 16px 20px;
  background: #ffffff;
  border-bottom: 1px solid var(--glass-border);
  font-weight: 700;
  font-size: 15px;
  color: var(--text-primary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.chapter-playlist {
  flex: 1;
  overflow-y: auto;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.chapter-group {
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.chapter-group-title {
  padding: 10px 14px;
  font-size: 13px;
  font-weight: 700;
  color: var(--text-primary);
  background: #f8fafc;
  border-bottom: 1px solid var(--glass-border);
}

.section-item {
  padding: 10px 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: #334155;
  cursor: pointer;
  border-bottom: 1px solid #f1f5f9;
  transition: all 0.2s;
}

.section-item:last-child {
  border-bottom: none;
}

.section-item:hover {
  background: #eef2ff;
  color: var(--primary);
}

.section-item.active {
  background: #e0e7ff;
  color: #4338ca;
  border-left: 3px solid var(--primary);
  font-weight: 600;
}

/* -------------------------------------------------------------
   课程购买与收银台 (Cashier Modal)
   ------------------------------------------------------------- */
.checkout-modal {
  width: 90vw;
  max-width: 620px;
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: 0 25px 50px -12px rgba(15, 23, 42, 0.2);
  overflow: hidden;
  animation: modalPop 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.pay-method-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin: 16px 0;
}

.pay-tab {
  padding: 12px;
  text-align: center;
  background: #f8fafc;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.pay-tab:hover, .pay-tab.active {
  background: #eef2ff;
  border-color: var(--primary);
  color: var(--primary);
}

.qr-box {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 16px;
  display: inline-block;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--glass-border);
  position: relative;
}

.course-price-box {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.price-now {
  font-size: 22px;
  font-weight: 800;
  color: #dc2626;
}

.price-origin {
  font-size: 13px;
  color: var(--text-muted);
  text-decoration: line-through;
}

.card-action-bar {
  display: flex;
  gap: 8px;
  margin-top: 14px;
}

/* -------------------------------------------------------------
   课程卡片与前台网格基础定义
   ------------------------------------------------------------- */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}

.course-card {
  background: #ffffff;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  box-shadow: 0 2px 8px -2px rgba(15, 23, 42, 0.05);
}

.course-card:hover {
  border-color: var(--primary-light);
  transform: translateY(-4px);
  box-shadow: 0 12px 24px -4px rgba(79, 70, 229, 0.12), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
}

.course-banner {
  height: 160px;
  background: linear-gradient(135deg, #e0e7ff, #ede9fe);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.course-category-tag {
  position: absolute;
  top: 12px;
  left: 12px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid #c7d2fe;
  color: #4338ca;
}

.course-content {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.course-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
  line-height: 1.4;
  transition: color 0.2s;
}

.course-name:hover {
  color: var(--primary);
}

.course-desc {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 14px;
  line-height: 1.6;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.course-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--text-muted);
  padding-top: 12px;
  border-top: 1px solid #f1f5f9;
}

.portal-features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.portal-dual-split {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 24px;
  margin-bottom: 40px;
}

/* -------------------------------------------------------------
   全面响应式与移动端自适应 (Responsive Breakpoints)
   ------------------------------------------------------------- */

/* 1. 笔记本与平板大屏 (< 1200px) */
@media screen and (max-width: 1200px) {
  .portal-features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .portal-container {
    padding: 24px 20px 48px;
  }
}

/* 2. 平板竖屏与小屏设备 (< 992px) */
@media screen and (max-width: 992px) {
  /* 后台管理端响应式转换：侧边栏转为顶部水平菜单 */
  #app-layout {
    flex-direction: column;
  }
  .sidebar {
    width: 100%;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--glass-border);
  }
  .nav-group {
    display: flex;
    flex-direction: row;
    overflow-x: auto;
    white-space: nowrap;
    padding: 8px 12px;
    gap: 8px;
    -webkit-overflow-scrolling: touch;
  }
  .nav-title {
    display: none;
  }
  .sidebar-footer {
    display: none;
  }
  .topbar {
    height: auto;
    padding: 10px 16px;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
  }
  .topbar-left {
    min-width: 0;
    flex: 1 1 auto;
  }
  .topbar-left .page-title {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 280px;
  }
  .topbar-right {
    flex-shrink: 0;
  }
  .quick-actions {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    align-items: center;
    gap: 8px;
  }
  .dashboard-split-grid {
    grid-template-columns: 1fr !important;
    gap: 16px !important;
  }

  /* 影院播放视窗改为上下布局 */
  .cinema-modal {
    width: 96vw;
    height: 94vh;
  }
  .cinema-body {
    grid-template-columns: 1fr;
    overflow-y: auto;
  }
  .cinema-sidebar {
    max-height: 380px;
    border-left: none;
    border-top: 1px solid var(--glass-border);
  }

  /* 前台双联展区 */
  .portal-dual-split {
    grid-template-columns: 1fr;
  }
}

/* 3. 手机与窄屏移动端全功能深度自适应 (< 768px 全界面覆盖) */
@media screen and (max-width: 768px) {
  /* ================= 前台学员门户自适应 ================= */
  .portal-layout {
    padding-bottom: calc(64px + env(safe-area-inset-bottom, 10px));
  }

  /* 前台单行轻量 Header */
  .portal-nav {
    height: 54px;
    padding: 0 12px;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    background: rgba(255, 255, 255, 0.96);
    box-shadow: 0 1px 4px rgba(15, 23, 42, 0.05);
  }

  .portal-nav-brand a {
    gap: 8px !important;
  }
  .portal-brand-logo {
    width: 32px;
    height: 32px;
    font-size: 17px;
    border-radius: 8px;
  }
  .portal-brand-title {
    font-size: 15px;
  }
  .portal-brand-sub {
    display: none;
  }
  .portal-nav-links {
    display: none !important;
  }
  .portal-nav-actions {
    gap: 6px;
  }
  .portal-btn-label {
    display: none;
  }
  .portal-admin-btn, .portal-orders-btn {
    padding: 6px 10px !important;
    font-size: 12px !important;
  }
  .portal-user-profile {
    padding: 2px 8px 2px 3px !important;
    gap: 5px !important;
  }
  .portal-user-meta {
    max-width: 60px;
  }
  .portal-user-meta span:first-child {
    font-size: 12px !important;
  }
  .portal-user-role {
    display: none;
  }
  .portal-nav-actions .logout-btn {
    width: 28px !important;
    height: 28px !important;
    font-size: 12px !important;
  }

  /* 前台移动端专属固定底栏 TabBar */
  .portal-mobile-tabbar {
    display: flex;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: calc(56px + env(safe-area-inset-bottom, 8px));
    padding-bottom: env(safe-area-inset-bottom, 8px);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid #e2e8f0;
    box-shadow: 0 -4px 16px rgba(15, 23, 42, 0.06);
    z-index: 1000;
    justify-content: space-around;
    align-items: center;
  }

  .mobile-tab-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    flex: 1;
    height: 100%;
    color: #64748b;
    text-decoration: none;
    font-size: 10px;
    font-weight: 500;
    position: relative;
    transition: all 0.15s ease;
    -webkit-tap-highlight-color: transparent;
  }
  .mobile-tab-icon {
    font-size: 20px;
    line-height: 1.1;
    margin-bottom: 2px;
    transition: transform 0.15s cubic-bezier(0.34, 1.56, 0.64, 1);
  }
  .mobile-tab-label {
    letter-spacing: -0.2px;
  }
  .mobile-tab-icon-wrap {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
  .mobile-tab-badge {
    position: absolute;
    top: -2px;
    right: -13px;
    font-size: 8px;
    font-weight: 700;
    padding: 1px 4px;
    border-radius: 6px;
    background: #3b82f6;
    color: #fff;
    line-height: 1;
    transform: scale(0.85);
  }
  .mobile-tab-badge.badge-live {
    background: #ef4444;
    box-shadow: 0 0 6px rgba(239, 68, 68, 0.5);
  }
  .mobile-tab-item.active {
    color: var(--primary);
    font-weight: 700;
  }
  .mobile-tab-item.active .mobile-tab-icon {
    transform: scale(1.15) translateY(-1px);
  }
  .mobile-tab-item.active::after {
    content: '';
    position: absolute;
    top: 0;
    left: 28%;
    right: 28%;
    height: 2px;
    background: var(--primary);
    border-radius: 0 0 2px 2px;
  }

  /* 视差 Hero 横幅自适应 */
  .portal-hero {
    padding: 32px 14px 26px;
  }
  .portal-hero h1 {
    font-size: 24px;
    line-height: 1.35;
    letter-spacing: -0.5px;
  }
  .portal-hero p {
    font-size: 13px;
    margin-bottom: 20px;
    line-height: 1.6;
  }
  .portal-hero-actions {
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 100%;
    max-width: 320px;
    margin: 0 auto 20px;
  }
  .portal-hero-actions .btn {
    width: 100%;
    justify-content: center;
    padding: 11px 16px !important;
    font-size: 14px !important;
  }
  .portal-stats-row {
    gap: 8px;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 6px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .portal-stats-row::-webkit-scrollbar {
    display: none;
  }
  .portal-stat-chip {
    padding: 6px 12px;
    font-size: 12px;
    white-space: nowrap;
  }
  .portal-features-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .course-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }
  .portal-category-pills {
    display: flex;
    overflow-x: auto;
    white-space: nowrap;
    gap: 8px;
    padding-bottom: 8px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .portal-category-pills::-webkit-scrollbar {
    display: none;
  }

  /* ================= 互动直播研学教室 (全屏/大厅移动端) ================= */
  .live-container {
    display: flex !important;
    flex-direction: column !important;
    height: auto !important;
    min-height: calc(100vh - 120px) !important;
    gap: 12px !important;
  }
  .video-player-box {
    width: 100% !important;
    aspect-ratio: 16 / 9 !important;
    height: auto !important;
    min-height: 200px !important;
    max-height: 260px !important;
    flex: none !important;
    border-radius: 12px !important;
  }
  .video-controls {
    padding: 8px 12px !important;
    flex-wrap: wrap !important;
    gap: 8px !important;
    font-size: 11px !important;
  }
  .video-controls .btn {
    padding: 4px 8px !important;
    font-size: 11px !important;
  }
  .chat-panel {
    height: 380px !important;
    min-height: 320px !important;
    border-radius: 12px !important;
  }
  .chat-messages {
    padding: 12px !important;
    gap: 8px !important;
  }
  .chat-input-bar {
    padding: 8px 12px !important;
  }

  /* ================= 直播研训大厅横幅移动端优化 ================= */
  .live-hall-hero {
    padding: 18px 14px !important;
    margin-bottom: 16px !important;
    border-radius: 16px !important;
  }
  .live-hero-bg-icon {
    display: none !important;
  }
  .live-hero-header {
    margin-bottom: 10px !important;
  }
  .live-hall-title {
    font-size: 18px !important;
    line-height: 1.35 !important;
    margin-bottom: 8px !important;
  }
  .live-hall-desc {
    font-size: 12px !important;
    margin-bottom: 14px !important;
    line-height: 1.5 !important;
  }
  .live-quick-enter-box {
    width: 100% !important;
    max-width: 100% !important;
    padding: 4px 6px 4px 10px !important;
    box-sizing: border-box !important;
    display: flex !important;
    align-items: center !important;
    gap: 6px !important;
  }
  .live-room-input {
    flex: 1 1 auto !important;
    width: auto !important;
    min-width: 0 !important;
    padding: 8px 6px !important;
    font-size: 13px !important;
  }
  .live-enter-btn {
    flex-shrink: 0 !important;
    white-space: nowrap !important;
    min-width: 88px !important;
    padding: 8px 14px !important;
    font-size: 13px !important;
    line-height: 1 !important;
    border-radius: var(--radius-md) !important;
  }
  .live-teacher-desktop-wrap {
    display: none !important;
  }
  .live-teacher-mobile-wrap {
    display: block !important;
    width: 100% !important;
    margin-top: 12px !important;
  }
  .live-create-btn-mobile {
    width: 100% !important;
    justify-content: center !important;
    padding: 10px 16px !important;
    font-size: 13px !important;
  }

  /* ================= 后台管理中台 (Admin Shell 移动端) ================= */
  #app-layout {
    flex-direction: column !important;
  }
  .sidebar {
    width: 100% !important;
    height: auto !important;
    box-shadow: none !important;
    border-right: none !important;
    border-bottom: 1px solid var(--glass-border) !important;
    background: #ffffff !important;
  }
  .brand-header {
    padding: 10px 14px !important;
    display: flex !important;
    justify-content: space-between !important;
    align-items: center !important;
  }
  .brand-left-wrap {
    display: flex !important;
    align-items: center !important;
    gap: 8px !important;
  }
  .brand-icon {
    width: 32px !important;
    height: 32px !important;
    font-size: 16px !important;
    border-radius: 8px !important;
  }
  .brand-text h1 {
    font-size: 15px !important;
  }
  .brand-text span {
    display: none !important;
  }
  .admin-mobile-top-user {
    display: flex !important;
    align-items: center !important;
    gap: 8px !important;
  }
  .admin-mobile-role-badge {
    font-size: 11px !important;
    padding: 2px 8px !important;
    border-radius: 999px !important;
    background: #eff6ff !important;
    color: #1d4ed8 !important;
    font-weight: 600 !important;
    border: 1px solid #bfdbfe !important;
  }
  .nav-group {
    display: flex !important;
    flex-direction: row !important;
    overflow-x: auto !important;
    white-space: nowrap !important;
    padding: 6px 10px !important;
    gap: 6px !important;
    background: #f8fafc !important;
    border-top: 1px solid #f1f5f9 !important;
    -webkit-overflow-scrolling: touch !important;
    scrollbar-width: none !important;
  }
  .nav-group::-webkit-scrollbar {
    display: none !important;
  }
  .nav-title {
    display: none !important;
  }
  .nav-item {
    padding: 6px 12px !important;
    font-size: 12px !important;
    border-radius: var(--radius-full) !important;
    background: #ffffff !important;
    border: 1px solid #e2e8f0 !important;
    flex-shrink: 0 !important;
    display: inline-flex !important;
    align-items: center !important;
    gap: 4px !important;
  }
  .nav-item.active {
    background: #eff6ff !important;
    border-color: #bfdbfe !important;
    color: var(--primary) !important;
    font-weight: 700 !important;
  }
  .nav-badge {
    font-size: 8px !important;
    padding: 1px 4px !important;
    margin-left: 2px !important;
  }
  .sidebar-footer {
    display: none !important;
  }
  .topbar {
    height: 50px !important;
    padding: 0 12px !important;
    display: flex !important;
    flex-direction: row !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 8px !important;
    background: #ffffff !important;
    border-bottom: 1px solid #f1f5f9 !important;
    box-sizing: border-box !important;
  }
  .topbar-left {
    min-width: 0 !important;
    flex: 1 1 auto !important;
    display: flex !important;
    align-items: center !important;
    gap: 6px !important;
    overflow: hidden !important;
  }
  .topbar-left .page-title {
    font-size: 14px !important;
    font-weight: 700 !important;
    color: #0f172a !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    max-width: 220px !important;
    line-height: 1 !important;
    margin: 0 !important;
  }
  .topbar-left .role-pill {
    display: none !important;
  }
  .topbar-right {
    flex-shrink: 0 !important;
    display: flex !important;
    align-items: center !important;
  }
  .quick-actions {
    display: flex !important;
    flex-direction: row !important;
    flex-wrap: nowrap !important;
    align-items: center !important;
    gap: 6px !important;
  }
  .admin-top-btn {
    padding: 5px 10px !important;
    font-size: 12px !important;
    white-space: nowrap !important;
    height: 30px !important;
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    line-height: 1 !important;
    border-radius: 6px !important;
  }
  .admin-top-btn-create {
    display: none !important; /* 关键：移动端顶栏隐藏全局冗余发课按钮，由各个子业务页按钮独立承接，杜绝挤压换行 */
  }
  .admin-btn-text {
    display: none !important;
  }
  .admin-btn-short-text {
    display: inline !important;
  }

  /* 统一业务页面顶部响应式排版 */
  .admin-view-header {
    display: flex !important;
    flex-direction: column !important;
    align-items: stretch !important;
    gap: 12px !important;
    margin-bottom: 16px !important;
  }
  .admin-view-header .btn {
    width: 100% !important;
    justify-content: center !important;
    padding: 10px 16px !important;
    font-size: 13px !important;
  }

  /* 管理控制台主体内边距 */
  .content-area {
    padding: 12px 14px 28px !important;
  }

  /* ================= 仪表盘 强力保证 2×2 精巧宫格 ================= */
  .stats-grid {
    display: grid !important;
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 10px !important;
    margin-bottom: 14px !important;
  }
  .stat-card {
    padding: 12px 10px !important;
    border-radius: 12px !important;
    min-height: 80px !important;
    display: flex !important;
    flex-direction: column !important;
    justify-content: space-between !important;
    background: #ffffff !important;
    border: 1px solid #e2e8f0 !important;
  }
  .stat-val {
    font-size: 22px !important;
    font-weight: 800 !important;
    margin: 4px 0 2px !important;
    line-height: 1.1 !important;
  }
  .stat-title {
    font-size: 11px !important;
    color: #64748b !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }
  .stat-change {
    font-size: 10px !important;
    white-space: nowrap !important;
  }

  /* 工作台下方的快捷双栏卡片转为单列垂直流 */
  .content-area > div[style*="grid-template-columns: 2fr 1.2fr"],
  .content-area > div[style*="grid-template-columns: 1fr 1fr"] {
    display: flex !important;
    flex-direction: column !important;
    gap: 14px !important;
  }

  /* ================= 数据表格触屏弹性保护 (Table Responsive) ================= */
  .table-container, .panel-body, div[style*="overflow-x: auto"] {
    overflow-x: auto !important;
    -webkit-overflow-scrolling: touch !important;
  }
  table {
    min-width: 600px !important;
  }

  /* ================= 全真考场答题视窗 (#full-exam-hall) ================= */
  .exam-header-bar {
    height: auto !important;
    padding: 8px 12px !important;
    flex-direction: column !important;
    align-items: stretch !important;
    gap: 8px !important;
  }
  .exam-progress-wrap {
    width: 100% !important;
  }
  .exam-monitor-actions {
    justify-content: space-between !important;
    width: 100% !important;
  }
  .exam-split-layout {
    display: flex !important;
    flex-direction: column !important;
    height: auto !important;
    overflow-y: auto !important;
  }
  .exam-question-main {
    padding: 12px !important;
  }
  .exam-card-body {
    padding: 18px 14px !important;
    border-radius: 12px !important;
  }
  .exam-sidebar {
    border-left: none !important;
    border-top: 1px solid #e2e8f0 !important;
    padding: 14px !important;
    max-height: none !important;
    box-shadow: none !important;
  }

  /* ================= 演示切号浮窗移动端精巧缩小与半透明贴边 ================= */
  #demo-assistant-widget {
    bottom: calc(64px + env(safe-area-inset-bottom, 8px)) !important;
    right: 8px !important;
    transform: scale(0.88) !important;
    transform-origin: bottom right !important;
    opacity: 0.85 !important;
  }
  #demo-assistant-widget:hover, #demo-assistant-widget:active {
    opacity: 1 !important;
  }
  #demo-assistant-widget button {
    padding: 5px 10px !important;
    font-size: 11px !important;
    border-radius: 16px !important;
    background: rgba(15, 23, 42, 0.9) !important;
    backdrop-filter: blur(8px) !important;
  }
  #demo-assistant-menu {
    right: 0 !important;
    width: 240px !important;
    bottom: 40px !important;
  }

  .modal-box, .checkout-modal {
    width: 95vw !important;
    max-width: 95vw !important;
    max-height: 90vh !important;
    padding: 0 !important;
    margin: 8px auto !important;
  }
  .pay-method-tabs {
    grid-template-columns: 1fr !important;
    gap: 8px !important;
  }

  .portal-footer {
    padding: 24px 16px;
    text-align: center;
  }
  .portal-footer > div {
    justify-content: center !important;
    text-align: center;
  }
}

/* 4. 超小屏手机 (< 440px) 保持 2x2 宫格，只微调超小屏字号 */
@media screen and (max-width: 440px) {
  .portal-hero h1 {
    font-size: 21px;
  }
  .live-hall-title {
    font-size: 16px !important;
  }
  .card-action-bar {
    flex-direction: column;
  }
  .card-action-bar button, .card-action-bar a {
    width: 100%;
  }
}