/* 现代化全局样式 */
:root {
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --success-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --warning-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
  --dark-bg: #0a0a0a;
  --card-bg: rgba(255, 255, 255, 0.05);
  --card-border: rgba(255, 255, 255, 0.1);
  --text-primary: #ffffff;
  --text-secondary: #b0b0b0;
  --text-muted: #888888;
  --primary-color: #667eea;
  --primary-dark: #5a6fd8;
  --secondary-color: #764ba2;
  --success-color: #28a745;
  --warning-color: #ffc107;
  --danger-color: #dc3545;
  --info-color: #17a2b8;
  --light-color: #f8f9fa;
  --dark-color: #343a40;
  --border-color: #dee2e6;
  --shadow-light: 0 2px 8px rgba(0,0,0,0.1);
  --shadow-medium: 0 4px 16px rgba(0,0,0,0.15);
  --shadow-heavy: 0 8px 32px rgba(0,0,0,0.2);
  --border-radius: 12px;
  --border-radius-lg: 20px;
  --transition: all 0.3s ease;
}

/* 消息提醒样式 */
.nav-notifications {
  position: relative;
  margin-right: 1rem;
  z-index: 1;
}

.notification-toggle {
  position: relative;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border: none;
  color: #ffffff;
  font-size: 1.1rem;
  padding: 0.5rem;
  border-radius: 16px;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  box-shadow: 
    0 8px 25px rgba(102, 126, 234, 0.4),
    0 4px 10px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
  overflow: visible;
  backdrop-filter: blur(10px);
  z-index: 1;
}

.notification-toggle::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.2) 0%, rgba(255,255,255,0.1) 100%);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.notification-toggle:hover::before {
  opacity: 1;
}

.notification-toggle:hover {
  transform: translateY(-3px) scale(1.08);
  box-shadow: 
    0 15px 35px rgba(102, 126, 234, 0.6),
    0 8px 15px rgba(0, 0, 0, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.3);
  background: linear-gradient(135deg, #7c3aed 0%, #8b5cf6 100%);
}

.notification-indicator {
  position: absolute;
  top: -8px;
  right: -8px;
  background: linear-gradient(45deg, #ff6b6b, #ff8e8e);
  border-radius: 12px;
  min-width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid #ffffff;
  box-shadow: 0 4px 12px rgba(255, 107, 107, 0.4);
  z-index: 1000;
  animation: notificationPulse 2s infinite;
}

.notification-count {
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
  line-height: 1;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
  padding: 0 4px;
  min-width: 16px;
  text-align: center;
}

@keyframes notificationPulse {
  0% { 
    transform: scale(1);
    box-shadow: 0 4px 12px rgba(255, 107, 107, 0.4);
  }
  50% { 
    transform: scale(1.1);
    box-shadow: 0 6px 16px rgba(255, 107, 107, 0.6);
  }
  100% { 
    transform: scale(1);
    box-shadow: 0 4px 12px rgba(255, 107, 107, 0.4);
  }
}

/* 添加图标动画效果 */
.notification-toggle i {
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.2));
}

.notification-toggle:hover i {
  transform: rotate(20deg) scale(1.1);
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.3));
}

/* 添加点击动画 */
.notification-toggle:active {
  transform: translateY(-1px) scale(1.02);
  transition: all 0.1s ease;
}

.notification-toggle:active i {
  transform: rotate(10deg) scale(0.95);
}

.notification-dropdown {
  position: absolute;
  top: 100%;
  right: 0;
  width: 350px;
  background: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-heavy);
  z-index: 1000;
  display: none;
  max-height: 400px;
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.notification-dropdown.show {
  display: block;
  animation: slideDown 0.3s ease;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.notification-header {
  padding: 1rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--light-color);
  border-radius: var(--border-radius) var(--border-radius) 0 0;
}

.notification-header h4 {
  margin: 0;
  color: var(--dark-color);
  font-size: 1rem;
  font-weight: 600;
}

.mark-all-read {
  background: var(--primary-color);
  color: white;
  border: none;
  padding: 0.25rem 0.75rem;
  border-radius: 6px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
}

.mark-all-read:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

.notification-list {
  max-height: 300px;
  overflow-y: auto;
  background: white;
}

.notification-loading {
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.notification-item {
  padding: 1rem;
  border-bottom: 1px solid #f0f0f0;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

.notification-item:hover {
  background: #f8f9fa;
}

.notification-item.unread {
  background: #e3f2fd;
  border-left: 3px solid var(--info-color);
}

.notification-item.unread::before {
  content: '';
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 8px;
  height: 8px;
  background: var(--info-color);
  border-radius: 50%;
}

.notification-title {
  font-weight: 600;
  color: var(--dark-color);
  margin-bottom: 0.25rem;
  font-size: 0.9rem;
}

.notification-content {
  color: var(--text-muted);
  font-size: 0.8rem;
  line-height: 1.4;
  margin-bottom: 0.5rem;
}

.notification-time {
  color: var(--text-muted);
  font-size: 0.7rem;
}

.notification-action {
  margin-top: 0.5rem;
}

.notification-action a {
  display: inline-block;
  background: var(--primary-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 4px;
  text-decoration: none;
  font-size: 0.8rem;
  transition: var(--transition);
}

.notification-action a:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

.notification-empty {
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  font-style: italic;
}

.notification-footer {
  padding: 1rem;
  text-align: center;
  border-top: 1px solid var(--border-color);
  background: var(--light-color);
  border-radius: 0 0 var(--border-radius) var(--border-radius);
}

.view-all-link {
  color: var(--primary-color);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition);
}

.view-all-link:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

/* 消息类型样式 */
.notification-item.type-info {
  border-left-color: var(--info-color);
}

.notification-item.type-warning {
  border-left-color: var(--warning-color);
}

.notification-item.type-success {
  border-left-color: var(--success-color);
}

.notification-item.type-error {
  border-left-color: var(--danger-color);
}

.notification-item.type-task {
  border-left-color: var(--primary-color);
}

.notification-item.type-announcement {
  border-left-color: var(--secondary-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
  .notification-dropdown {
    width: 300px;
    right: -50px;
  }
  
  .notification-header {
    padding: 0.75rem;
  }
  
  .notification-item {
    padding: 0.75rem;
  }
  
  .notification-list {
    max-height: 250px;
  }
}

* {
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--dark-bg);
  margin: 0;
  padding: 0;
  min-height: 100vh;
  position: relative;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.3) 0%, transparent 50%),
    radial-gradient(circle at 40% 40%, rgba(120, 219, 255, 0.2) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* 全新设计的现代化导航栏 */
.modern-navbar {
  background: rgba(255, 255, 255, 0.95) !important;
  backdrop-filter: blur(20px) !important;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2) !important;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1) !important;
  position: fixed !important;
  top: 0 !important;
  left: 0 !important;
  right: 0 !important;
  z-index: 9999 !important;
  padding: 0 !important;
  width: 100% !important;
  height: 80px !important;
  display: flex !important;
  align-items: center !important;
  transition: all 0.3s ease !important;
}

.nav-container {
  max-width: 1400px !important;
  margin: 0 auto !important;
  padding: 0 2rem !important;
  display: flex !important;
  align-items: center !important;
  justify-content: space-between !important;
  height: 100% !important;
  width: 100% !important;
}

/* Logo区域 - 现代化设计 */
.nav-brand {
  display: flex !important;
  align-items: center !important;
}

.brand-link {
  display: flex !important;
  align-items: center !important;
  gap: 1rem !important;
  text-decoration: none !important;
  color: #1a202c !important;
  transition: all 0.3s ease !important;
  padding: 0.5rem 1rem !important;
  border-radius: 16px !important;
  background: rgba(102, 126, 234, 0.1) !important;
  border: 1px solid rgba(102, 126, 234, 0.2) !important;
}

.brand-link:hover {
  color: #667eea !important;
  text-decoration: none !important;
  transform: translateY(-2px) !important;
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.2) !important;
  background: rgba(102, 126, 234, 0.15) !important;
}

.brand-icon {
  width: 48px !important;
  height: 48px !important;
  border-radius: 16px !important;
  background: var(--primary-gradient) !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  font-size: 1.4rem !important;
  color: white !important;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4) !important;
  transition: all 0.3s ease !important;
}

.brand-link:hover .brand-icon {
  transform: scale(1.1) !important;
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.6) !important;
}

.brand-text {
  font-size: 1.4rem !important;
  font-weight: 700 !important;
  background: var(--primary-gradient) !important;
  -webkit-background-clip: text !important;
  -webkit-text-fill-color: transparent !important;
  background-clip: text !important;
  letter-spacing: -0.02em !important;
}

/* 导航菜单 - 现代化设计 */
.nav-menu {
  display: flex !important;
  align-items: center !important;
  gap: 1rem !important;
  position: relative !important;
  z-index: 10000 !important;
}

.nav-item {
  position: relative !important;
}

.nav-link {
  display: flex !important;
  align-items: center !important;
  gap: 0.5rem !important;
  padding: 0.75rem 1.5rem !important;
  color: #4a5568 !important;
  text-decoration: none !important;
  border-radius: 12px !important;
  transition: all 0.3s ease !important;
  font-weight: 600 !important;
  position: relative !important;
  overflow: hidden !important;
  background: rgba(255, 255, 255, 0.8) !important;
  border: 1px solid rgba(255, 255, 255, 0.3) !important;
  backdrop-filter: blur(10px) !important;
}

.nav-link:hover {
  color: #667eea !important;
  background: rgba(102, 126, 234, 0.1) !important;
  transform: translateY(-2px) !important;
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.2) !important;
  border-color: rgba(102, 126, 234, 0.3) !important;
}

.nav-link i {
  font-size: 1.1rem !important;
  transition: all 0.3s ease !important;
}

.nav-link:hover i {
  transform: scale(1.1) !important;
  color: #667eea !important;
}

/* 用户菜单 - 现代化设计 */
.nav-user {
  display: flex !important;
  align-items: center !important;
  position: relative !important;
  z-index: 10001 !important;
}

.user-dropdown {
  position: relative !important;
}

.user-toggle {
  display: flex !important;
  align-items: center !important;
  gap: 0.8rem !important;
  background: rgba(255, 255, 255, 0.9) !important;
  border: 1px solid rgba(255, 255, 255, 0.3) !important;
  border-radius: 16px !important;
  padding: 0.75rem 1.2rem !important;
  color: #1a202c !important;
  cursor: pointer !important;
  transition: all 0.3s ease !important;
  font-size: 0.95rem !important;
  font-weight: 600 !important;
  backdrop-filter: blur(10px) !important;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1) !important;
}

.user-toggle:hover {
  background: rgba(102, 126, 234, 0.1) !important;
  border-color: rgba(102, 126, 234, 0.3) !important;
  transform: translateY(-2px) !important;
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.2) !important;
  color: #667eea !important;
}

.user-avatar {
  width: 36px !important;
  height: 36px !important;
  border-radius: 50% !important;
  background: var(--primary-gradient) !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  font-size: 1rem !important;
  color: white !important;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3) !important;
  transition: all 0.3s ease !important;
}

.user-toggle:hover .user-avatar {
  transform: scale(1.1) !important;
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5) !important;
}

.user-name {
  font-weight: 600 !important;
  color: inherit !important;
}

.user-toggle i {
  transition: all 0.3s ease !important;
}

.user-toggle:hover i {
  transform: rotate(180deg) !important;
  color: #667eea !important;
}

.user-menu {
  position: absolute !important;
  top: 100% !important;
  right: 0 !important;
  margin-top: 0.8rem !important;
  background: rgba(255, 255, 255, 0.95) !important;
  backdrop-filter: blur(20px) !important;
  border: 1px solid rgba(255, 255, 255, 0.3) !important;
  border-radius: 16px !important;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15) !important;
  min-width: 220px !important;
  max-height: 400px !important;
  opacity: 0 !important;
  visibility: hidden !important;
  transform: translateY(-10px) !important;
  transition: all 0.3s ease !important;
  z-index: 1000 !important;
  overflow: hidden !important;
  display: flex !important;
  flex-direction: column !important;
}

/* 菜单滚动控制按钮 */
.menu-scroll-controls {
  position: relative !important;
  display: flex !important;
  justify-content: center !important;
  gap: 0.5rem !important;
  padding: 0.5rem !important;
  background: rgba(102, 126, 234, 0.1) !important;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05) !important;
  z-index: 10 !important;
}

.scroll-btn {
  background: rgba(102, 126, 234, 0.8) !important;
  border: none !important;
  color: white !important;
  width: 24px !important;
  height: 24px !important;
  border-radius: 50% !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  cursor: pointer !important;
  transition: all 0.3s ease !important;
  font-size: 0.7rem !important;
  opacity: 0.7 !important;
}

.scroll-btn:hover {
  background: rgba(102, 126, 234, 1) !important;
  opacity: 1 !important;
  transform: scale(1.1) !important;
}

.scroll-btn:disabled {
  opacity: 0.3 !important;
  cursor: not-allowed !important;
  transform: none !important;
}

.scroll-btn:disabled:hover {
  background: rgba(102, 126, 234, 0.8) !important;
  transform: none !important;
}

/* 菜单内容容器 */
.menu-content {
  flex: 1 !important;
  overflow-y: auto !important;
  overflow-x: hidden !important;
  max-height: 350px !important;
  scrollbar-width: thin !important;
  scrollbar-color: rgba(102, 126, 234, 0.3) transparent !important;
}

.menu-content::-webkit-scrollbar {
  width: 4px !important;
}

.menu-content::-webkit-scrollbar-track {
  background: transparent !important;
}

.menu-content::-webkit-scrollbar-thumb {
  background: rgba(102, 126, 234, 0.3) !important;
  border-radius: 2px !important;
}

.menu-content::-webkit-scrollbar-thumb:hover {
  background: rgba(102, 126, 234, 0.5) !important;
}

.user-dropdown:hover .user-menu {
  opacity: 1 !important;
  visibility: visible !important;
  transform: translateY(0) !important;
}

.user-menu-item {
  display: flex !important;
  align-items: center !important;
  gap: 0.8rem !important;
  padding: 0.75rem 1.2rem !important;
  color: #4a5568 !important;
  text-decoration: none !important;
  transition: all 0.3s ease !important;
  font-size: 0.9rem !important;
  font-weight: 500 !important;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05) !important;
}

.user-menu-item:last-child {
  border-bottom: none !important;
}

.user-menu-item:hover {
  background: rgba(102, 126, 234, 0.1) !important;
  color: #667eea !important;
  text-decoration: none !important;
  transform: translateX(5px) !important;
}

.user-menu-item i {
  width: 18px !important;
  text-align: center !important;
  font-size: 1rem !important;
  transition: all 0.3s ease !important;
}

.user-menu-item:hover i {
  transform: scale(1.1) !important;
  color: #667eea !important;
}

.user-menu-divider {
  height: 1px !important;
  background: rgba(0, 0, 0, 0.1) !important;
  margin: 0.5rem 0 !important;
}

.user-menu-header {
  padding: 0.5rem 1.2rem !important;
  font-size: 0.8rem !important;
  font-weight: 600 !important;
  color: #667eea !important;
  text-transform: uppercase !important;
  letter-spacing: 0.5px !important;
  background: rgba(102, 126, 234, 0.05) !important;
}

/* 移动端菜单按钮 */
.nav-toggle {
  display: none !important;
  flex-direction: column !important;
  gap: 4px !important;
  cursor: pointer !important;
  padding: 0.5rem !important;
  border-radius: 8px !important;
  background: rgba(255, 255, 255, 0.9) !important;
  border: 1px solid rgba(255, 255, 255, 0.3) !important;
}

.nav-toggle span {
  width: 24px !important;
  height: 2px !important;
  background: #4a5568 !important;
  border-radius: 2px !important;
  transition: all 0.3s ease !important;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .nav-container {
    padding: 0 1rem !important;
  }
  
  .nav-menu {
    display: none !important;
  }
  
  .nav-menu.show {
    display: flex !important;
    flex-direction: column !important;
    position: absolute !important;
    top: 100% !important;
    left: 0 !important;
    right: 0 !important;
    background: rgba(255, 255, 255, 0.95) !important;
    backdrop-filter: blur(20px) !important;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3) !important;
    padding: 1rem !important;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1) !important;
  }
  
  .nav-toggle {
    display: flex !important;
  }
  
  .brand-text {
    font-size: 1.2rem !important;
  }
  
  .brand-icon {
    width: 40px !important;
    height: 40px !important;
    font-size: 1.2rem !important;
  }
}

/* 确保移动端样式优先级更高 */
@media (max-width: 768px) {
  .nav-menu {
    display: none !important;
  }
  
  .nav-menu.show {
    display: block !important;
  }
}

/* 主容器 */
.main-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
  position: relative;
  z-index: 1;
}

/* Flash消息 */
.flash-container {
  position: fixed;
  top: 90px;
  right: 2rem;
  z-index: 1001;
  max-width: 400px;
}

.flash-message {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: rgba(10, 10, 10, 0.95);
  backdrop-filter: blur(20px);
  border: 1px solid var(--card-border);
  border-radius: var(--border-radius);
  padding: 1rem 1.5rem;
  margin-bottom: 1rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  animation: slideInRight 0.3s ease;
}

.flash-success {
  border-left: 4px solid var(--success-color);
}

.flash-danger {
  border-left: 4px solid var(--danger-color);
}

.flash-warning {
  border-left: 4px solid var(--warning-color);
}

.flash-info {
  border-left: 4px solid var(--info-color);
}

.flash-icon {
  font-size: 1.2rem;
  color: var(--text-primary);
}

.flash-content {
  flex: 1;
}

.flash-text {
  color: var(--text-primary);
  font-size: 0.9rem;
}

.flash-close {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 4px;
  transition: var(--transition);
}

.flash-close:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.1);
}

/* 页面内容 */
.page-content {
  min-height: calc(100vh - 200px);
}

/* 现代化页脚 */
.modern-footer {
  background: rgba(10, 10, 10, 0.95);
  backdrop-filter: blur(20px);
  border-top: 1px solid var(--card-border);
  margin-top: 4rem;
  padding: 2rem 0;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
}

.footer-brand i {
  color: var(--primary-color);
}

.footer-info {
  text-align: right;
}

.footer-info p {
  margin: 0.25rem 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.footer-copyright {
  text-align: center;
  padding-top: 1.5rem;
  border-top: 1px solid var(--card-border);
}

.footer-copyright p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-icp {
  margin-top: 0.5rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--card-border);
}

.footer-icp p {
  margin: 0.25rem 0;
  color: var(--text-muted);
  font-size: 0.8rem;
  line-height: 1.4;
}

.footer-icp a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-icp a:hover {
  color: var(--primary-color);
  text-decoration: underline;
}

/* 动画 */
@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(100%);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* 响应式设计 */
@media (max-width: 768px) {
  .nav-container {
    padding: 0 1rem;
    position: relative;
  }
  
  .nav-menu {
    display: none !important;
    position: absolute !important;
    top: 100% !important;
    left: 0 !important;
    right: 0 !important;
    background: #1a1a1a !important;
    border-top: 1px solid #333333 !important;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5) !important;
    z-index: 1000 !important;
    padding: 1rem 0 !important;
    flex-direction: column !important;
    align-items: stretch !important;
  }
  
  .nav-menu.show {
    display: block !important;
  }
  
  .nav-menu .nav-item {
    display: block;
    margin: 0;
    padding: 0;
  }
  
  .nav-menu .nav-link {
    display: flex !important;
    align-items: center !important;
    gap: 0.8rem !important;
    padding: 1rem 2rem !important;
    color: #ffffff !important;
    text-decoration: none !important;
    border-bottom: 1px solid #333333 !important;
    transition: var(--transition) !important;
    font-weight: 600 !important;
    font-size: 1.1rem !important;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5) !important;
  }
  
  .nav-menu .nav-link:hover {
    background: #333333 !important;
    color: #ffffff !important;
    text-decoration: none !important;
  }
  
  .nav-menu .nav-link:active {
    background: #444444 !important;
    color: #ffffff !important;
  }
  
  .nav-menu .nav-link i {
    width: 20px !important;
    text-align: center !important;
    color: #ffffff !important;
    font-size: 1.2rem !important;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5) !important;
  }
  
  .nav-toggle {
    display: flex !important;
    cursor: pointer !important;
    z-index: 1001 !important;
  }
  
  /* 用户菜单在移动端的样式 */
  .nav-user {
    margin-left: auto;
  }
  
  .user-dropdown {
    position: relative;
  }
  
  .user-menu {
    position: absolute !important;
    top: 100% !important;
    right: 0 !important;
    left: auto !important;
    background: #1a1a1a !important;
    border: 1px solid #333333 !important;
    border-radius: var(--border-radius) !important;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5) !important;
    min-width: 200px !important;
    max-height: 400px !important;
    z-index: 1001 !important;
    display: none !important;
    flex-direction: column !important;
    overflow: hidden !important;
  }
  
  /* 移动端菜单滚动控制 */
  .menu-scroll-controls {
    background: rgba(255, 255, 255, 0.1) !important;
    border-bottom: 1px solid #333333 !important;
  }
  
  .scroll-btn {
    background: rgba(255, 255, 255, 0.2) !important;
    color: #ffffff !important;
  }
  
  .scroll-btn:hover {
    background: rgba(255, 255, 255, 0.3) !important;
  }
  
  .menu-content {
    max-height: 350px !important;
  }
  
  .menu-content::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3) !important;
  }
  
  .menu-content::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.5) !important;
  }
  
  .user-menu.show {
    display: block !important;
  }
  
  .user-menu-item {
    display: flex !important;
    align-items: center !important;
    gap: 0.8rem !important;
    padding: 0.8rem 1rem !important;
    color: #ffffff !important;
    text-decoration: none !important;
    border-bottom: 1px solid #333333 !important;
    transition: var(--transition) !important;
    font-weight: 600 !important;
    font-size: 1rem !important;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5) !important;
  }
  
  .user-menu-item:hover {
    background: #333333 !important;
    color: #ffffff !important;
    text-decoration: none !important;
  }
  
  .user-menu-item:active {
    background: #444444 !important;
    color: #ffffff !important;
  }
  
  .user-menu-item i {
    color: #ffffff !important;
    font-size: 1.1rem !important;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5) !important;
  }
  
  .user-menu-item:last-child {
    border-bottom: none;
  }
  
  .user-menu-divider {
    height: 1px;
    background: #333333;
    margin: 0.5rem 0;
  }
  
  .user-menu-header {
    padding: 0.5rem 1rem !important;
    color: #cccccc !important;
    font-size: 0.8rem !important;
    font-weight: 600 !important;
    text-transform: uppercase !important;
  }
  
  /* 滚动锁定 */
  body.nav-open {
    overflow: hidden;
  }
  
  /* 确保移动端菜单文字非常显眼 - 强制覆盖所有可能的颜色设置 */
  .nav-menu,
  .nav-menu *,
  .nav-menu .nav-link,
  .nav-menu .nav-link span,
  .nav-menu .nav-link i,
  .nav-menu .nav-item,
  .nav-menu .nav-item * {
    color: #ffffff !important;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.7) !important;
    -webkit-text-stroke: 0.5px rgba(0, 0, 0, 0.3) !important;
    -webkit-text-fill-color: #ffffff !important;
  }
  
  /* 增强对比度 */
  .nav-menu .nav-link:hover,
  .nav-menu .nav-link:active,
  .user-menu-item:hover,
  .user-menu-item:active {
    color: #ffffff !important;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.8) !important;
    background: rgba(255, 255, 255, 0.15) !important;
  }
  
  /* 强制重置所有可能的颜色继承 */
  @media (max-width: 768px) {
    .nav-menu,
    .nav-menu * {
      all: unset !important;
      display: block !important;
      color: #ffffff !important;
      background: transparent !important;
      border: none !important;
      margin: 0 !important;
      padding: 0 !important;
      font-family: inherit !important;
      font-size: inherit !important;
      line-height: inherit !important;
      text-decoration: none !important;
    }
    
    .nav-menu .nav-link,
    .user-menu-item {
      display: flex !important;
      align-items: center !important;
      gap: 0.8rem !important;
      padding: 1rem 2rem !important;
      color: #ffffff !important;
      text-decoration: none !important;
      border-bottom: 1px solid #333333 !important;
      font-weight: 600 !important;
      font-size: 1.1rem !important;
      text-shadow: 0 1px 3px rgba(0, 0, 0, 0.7) !important;
      -webkit-text-fill-color: #ffffff !important;
    }
    
    .nav-menu .nav-link i,
    .user-menu-item i {
      color: #ffffff !important;
      font-size: 1.2rem !important;
      text-shadow: 0 1px 3px rgba(0, 0, 0, 0.7) !important;
      -webkit-text-fill-color: #ffffff !important;
    }
  }
  
  .main-container {
    padding: 1rem;
  }
  
  .footer-content {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
  
  .footer-info {
    text-align: center;
  }
  
  .flash-container {
    right: 1rem;
    left: 1rem;
    max-width: none;
  }
}

/* Bootstrap 核心样式 */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.5;
    color: #212529;
    background-color: #f8f9fa;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}

.col-md-3 { width: 25%; padding: 0 15px; }
.col-md-4 { width: 33.333333%; padding: 0 15px; }
.col-md-6 { width: 50%; padding: 0 15px; }
.col-md-8 { width: 66.666667%; padding: 0 15px; }
.col-md-9 { width: 75%; padding: 0 15px; }
.col-md-12 { width: 100%; padding: 0 15px; }

@media (max-width: 768px) {
    .col-md-3, .col-md-4, .col-md-6, .col-md-8, .col-md-9 {
        width: 100%;
    }
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 8px 16px;
    margin: 4px 2px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    text-decoration: none;
    text-align: center;
    transition: all 0.3s;
    font-size: 14px;
    line-height: 1.5;
}

.btn-primary {
    background-color: #007bff;
    color: white;
}

.btn-primary:hover {
    background-color: #0056b3;
}

.btn-success {
    background-color: #28a745;
    color: white;
}

.btn-success:hover {
    background-color: #1e7e34;
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #545b62;
}

.btn-lg {
    padding: 12px 24px;
    font-size: 18px;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 12px;
}

.d-grid {
    display: grid;
}

.gap-2 {
    gap: 0.5rem;
}

/* 卡片样式 */
.card {
    border: 1px solid #dee2e6;
    border-radius: 8px;
    background-color: white;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.card-header {
    padding: 16px;
    border-bottom: 1px solid #dee2e6;
    background-color: #f8f9fa;
    border-radius: 8px 8px 0 0;
}

.card-body {
    padding: 20px;
}

.card-footer {
    padding: 16px;
    border-top: 1px solid #dee2e6;
    background-color: #f8f9fa;
    border-radius: 0 0 8px 8px;
}

.bg-success {
    background-color: #28a745 !important;
}

.bg-primary {
    background-color: #007bff !important;
}

.text-white {
    color: white !important;
}

.text-center {
    text-align: center !important;
}

.shadow {
    box-shadow: 0 4px 8px rgba(0,0,0,0.1) !important;
}

/* 表单样式 */
.form-label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
}

.form-select, .form-control {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid #ced4da;
    border-radius: 4px;
    font-size: 14px;
    line-height: 1.5;
}

.form-select:focus, .form-control:focus {
    outline: none;
    border-color: #80bdff;
    box-shadow: 0 0 0 2px rgba(0,123,255,0.25);
}

.form-check {
    display: flex;
    align-items: center;
    margin-bottom: 8px;
}

.form-check-input {
    margin-right: 8px;
}

.form-check-label {
    margin-bottom: 0;
}

/* 间距工具类 */
.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: 0.25rem !important; }
.mb-2 { margin-bottom: 0.5rem !important; }
.mb-3 { margin-bottom: 1rem !important; }
.mb-4 { margin-bottom: 1.5rem !important; }
.mb-5 { margin-bottom: 3rem !important; }

.mt-2 { margin-top: 0.5rem !important; }
.mt-4 { margin-top: 1.5rem !important; }

.me-1 { margin-right: 0.25rem !important; }
.me-2 { margin-right: 0.5rem !important; }

.p-3 { padding: 1rem !important; }

/* 下拉菜单 */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-toggle::after {
    content: " ▼";
    font-size: 10px;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    background-color: white;
    border: 1px solid #dee2e6;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
    min-width: 160px;
    z-index: 1000;
    display: none;
    list-style: none;
    padding: 8px 0;
    margin: 0;
}

.dropdown-item {
    display: block;
    padding: 8px 16px;
    color: #212529;
    text-decoration: none;
    transition: background-color 0.3s;
}

.dropdown-item:hover {
    background-color: #f8f9fa;
}

.dropdown-divider {
    height: 1px;
    background-color: #dee2e6;
    margin: 8px 0;
    border: 0;
}

/* 警告框 */
.alert {
    padding: 12px 16px;
    margin: 16px 0;
    border-radius: 4px;
    border: 1px solid transparent;
}

.alert-success {
    background-color: #d4edda;
    border-color: #c3e6cb;
    color: #155724;
}

.alert-danger {
    background-color: #f8d7da;
    border-color: #f5c6cb;
    color: #721c24;
}

.alert-warning {
    background-color: #fff3cd;
    border-color: #ffeeba;
    color: #856404;
}

.alert-info {
    background-color: #d1ecf1;
    border-color: #bee5eb;
    color: #0c5460;
}

.alert-dismissible {
    position: relative;
    padding-right: 48px;
}

.btn-close {
    position: absolute;
    top: 12px;
    right: 16px;
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    padding: 0;
    width: 24px;
    height: 24px;
}

.btn-close:before {
    content: "×";
}

/* 列表样式 */
.list-unstyled {
    padding-left: 0;
    list-style: none;
}

.list-unstyled li {
    margin-bottom: 8px;
}

/* 文本颜色 */
.text-primary { color: #007bff !important; }
.text-success { color: #28a745 !important; }
.text-danger { color: #dc3545 !important; }
.text-warning { color: #ffc107 !important; }
.text-info { color: #17a2b8 !important; }
.text-muted { color: #6c757d !important; }

/* 图标替代 */
.fas {
    display: inline-block;
    font-style: normal;
    font-variant: normal;
    text-rendering: auto;
    line-height: 1;
    margin-right: 4px;
}

.fa-play:before { content: "▶"; }
.fa-folder:before { content: "📁"; }
.fa-folder-open:before { content: "📂"; }
.fa-chart-line:before { content: "📈"; }
.fa-list-ol:before { content: "📝"; }
.fa-cog:before { content: "⚙"; }
.fa-rocket:before { content: "🚀"; }
.fa-info-circle:before { content: "ℹ"; }
.fa-check:before { content: "✓"; }
.fa-lightbulb:before { content: "💡"; }
.fa-microchip:before { content: "🔧"; }
.fa-tachometer-alt:before { content: "📊"; }
.fa-dumbbell:before { content: "💪"; }
.fa-clipboard-list:before { content: "📋"; }
.fa-user:before { content: "👤"; }
.fa-user-edit:before { content: "✏"; }
.fa-history:before { content: "🕒"; }
.fa-sign-out-alt:before { content: "🚪"; }
.fa-sign-in-alt:before { content: "🔑"; }
.fa-user-plus:before { content: "👥"; }
.fa-exclamation-triangle:before { content: "⚠"; }
.fa-spinner:before { content: "⏳"; }
.fa-arrow-left:before { content: "←"; }
.fa-share:before { content: "🔗"; }
.fa-bell:before { content: "🔔"; }
.fa-bell-slash:before { content: "🔕"; }

/* 特殊样式 */
.lead {
    font-size: 18px;
    font-weight: 300;
    color: #6c757d;
}

.small {
    font-size: 12px;
}

.form-text {
    font-size: 12px;
    color: #6c757d;
}

.justify-content-center {
    justify-content: center;
}

.justify-content-md-between {
    justify-content: space-between;
}

.d-md-flex {
    display: flex;
}

.navbar-toggler {
    display: none;
}

@media (max-width: 768px) {
    .navbar-toggler {
        display: block;
        background: none;
        border: 1px solid rgba(255,255,255,0.3);
        color: white;
        padding: 4px 8px;
        border-radius: 4px;
    }
    
    .navbar-collapse {
        display: none;
    }
    
    .navbar-collapse.show {
        display: block;
    }
    
    .navbar-nav {
        flex-direction: column;
        margin-top: 12px;
    }
    
    .nav-item {
        margin: 4px 0;
    }
}

/* 自定义样式 */
body:not(.home-landing) {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.main-content {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    margin: 20px auto;
    padding: 30px;
    max-width: 1200px;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

.answer-option {
    padding: 12px 16px;
    margin: 8px 0;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    background: white;
}

.answer-option:hover {
    border-color: #007bff;
    background: rgba(0,123,255,0.1);
}

.answer-option.selected {
    border-color: #007bff;
    background: rgba(0,123,255,0.2);
}

.answer-option.correct {
    border-color: #28a745;
    background: rgba(40,167,69,0.2);
}

.answer-option.incorrect {
    border-color: #dc3545;
    background: rgba(220,53,69,0.2);
}

.footer {
    background: rgba(0,0,0,0.1);
    color: white;
    text-align: center;
    padding: 20px 0;
    margin-top: 40px;
}

.bg-success-subtle {
    background-color: rgba(25, 135, 84, 0.1);
}

.bg-danger-subtle {
    background-color: rgba(220, 53, 69, 0.1);
}

.bg-info-subtle {
    background-color: rgba(13, 202, 240, 0.1);
}

.fa-spin {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 提示框显示/隐藏 */
.show {
    display: block !important;
}

.fade {
    opacity: 0;
    transition: opacity 0.3s;
}

.fade.show {
    opacity: 1;
}