/* 全局样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary-color: #FF6B35;
  --primary-dark: #E55A2B;
  --secondary-color: #4CAF50;
  --bg-color: #F5F7FA;
  --card-bg: #FFFFFF;
  --text-primary: #333333;
  --text-secondary: #666666;
  --text-muted: #999999;
  --border-color: #E5E5E5;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
  --sidebar-width: 240px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  display: flex;
  min-height: 100vh;
}

/* 侧边栏 */
.sidebar {
  width: var(--sidebar-width);
  background: linear-gradient(180deg, #2C3E50 0%, #1A252F 100%);
  color: #FFFFFF;
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  z-index: 100;
  transition: transform 0.3s;
}

.sidebar.collapsed {
  transform: translateX(-100%);
}

.logo {
  padding: 24px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.logo i {
  font-size: 28px;
  color: var(--primary-color);
}

.logo span {
  font-size: 18px;
  font-weight: bold;
}

.nav-menu {
  flex: 1;
  padding: 16px 0;
  overflow-y: auto;
}

.nav-item {
  display: flex;
  align-items: center;
  padding: 14px 24px;
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: all 0.3s;
  gap: 12px;
}

.nav-item:hover {
  background-color: rgba(255, 255, 255, 0.1);
  color: #FFFFFF;
}

.nav-item.active {
  background-color: var(--primary-color);
  color: #FFFFFF;
}

.nav-item i {
  width: 20px;
  text-align: center;
}

.sidebar-footer {
  padding: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.logout-btn {
  width: 100%;
  padding: 12px;
  background-color: rgba(255, 255, 255, 0.1);
  border: none;
  border-radius: 8px;
  color: #FFFFFF;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: background-color 0.3s;
}

.logout-btn:hover {
  background-color: rgba(255, 255, 255, 0.2);
}

/* 主内容区 */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* 顶部栏 */
.header {
  background-color: var(--card-bg);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 50;
}

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

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--text-primary);
}

.page-title {
  font-size: 20px;
  font-weight: 600;
}

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

.user-info i {
  font-size: 24px;
  color: var(--primary-color);
}

/* 内容区域 */
.content {
  flex: 1;
  padding: 24px;
  overflow-y: auto;
}

/* 统计卡片 */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-bottom: 24px;
}

.stat-card {
  background-color: var(--card-bg);
  border-radius: 12px;
  padding: 24px;
  box-shadow: var(--shadow);
}

.stat-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.stat-card-title {
  font-size: 14px;
  color: var(--text-muted);
}

.stat-card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

.stat-card-icon.users { background-color: #E3F2FD; color: #2196F3; }
.stat-card-icon.articles { background-color: #FFF3E0; color: #FF9800; }
.stat-card-icon.videos { background-color: #F3E5F5; color: #9C27B0; }
.stat-card-icon.revenue { background-color: #E8F5E9; color: #4CAF50; }

.stat-card-value {
  font-size: 32px;
  font-weight: bold;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.stat-card-change {
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.stat-card-change.positive { color: var(--secondary-color); }
.stat-card-change.negative { color: #F44336; }

/* 表格 */
.card {
  background-color: var(--card-bg);
  border-radius: 12px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
}

.card-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-title {
  font-size: 18px;
  font-weight: 600;
}

.card-body {
  padding: 24px;
}

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

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

th {
  font-weight: 600;
  color: var(--text-secondary);
  background-color: #FAFAFA;
}

tr:hover {
  background-color: #FAFAFA;
}

/* 按钮 */
.btn {
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.3s;
}

.btn-primary {
  background-color: var(--primary-color);
  color: #FFFFFF;
}

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

.btn-secondary {
  background-color: #F5F5F5;
  color: var(--text-primary);
}

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

.btn-success {
  background-color: var(--secondary-color);
  color: #FFFFFF;
}

.btn-danger {
  background-color: #F44336;
  color: #FFFFFF;
}

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

/* 表单 */
.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  color: var(--text-primary);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: 14px;
  transition: border-color 0.3s;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--primary-color);
}

.form-textarea {
  min-height: 120px;
  resize: vertical;
}

/* 标签 */
.tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
}

.tag-success { background-color: #E8F5E9; color: #4CAF50; }
.tag-warning { background-color: #FFF3E0; color: #FF9800; }
.tag-danger { background-color: #FFEBEE; color: #F44336; }
.tag-info { background-color: #E3F2FD; color: #2196F3; }

/* 模态框 */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  align-items: center;
  justify-content: center;
}

.modal.show {
  display: flex;
}

.modal-content {
  background-color: var(--card-bg);
  border-radius: 12px;
  width: 90%;
  max-width: 800px;
  max-height: 90vh;
  overflow-y: auto;
  animation: modalIn 0.3s;
}

@keyframes modalIn {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: 18px;
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--text-muted);
}

.modal-body {
  padding: 24px;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

/* 加载状态 */
.loading {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(255, 255, 255, 0.9);
  z-index: 2000;
  align-items: center;
  justify-content: center;
}

.loading.show {
  display: flex;
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--border-color);
  border-top-color: var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* 图片上传 */
.upload-area {
  border: 2px dashed var(--border-color);
  border-radius: 12px;
  padding: 40px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s;
}

.upload-area:hover {
  border-color: var(--primary-color);
  background-color: #FFF5F0;
}

.upload-area i {
  font-size: 48px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.upload-area p {
  color: var(--text-secondary);
}

/* 图片预览 */
.image-preview {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.image-item {
  position: relative;
  aspect-ratio: 1;
  border-radius: 8px;
  overflow: hidden;
  background-color: #F5F5F5;
}

.image-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.image-item .delete-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background-color: rgba(0, 0, 0, 0.5);
  color: #FFFFFF;
  border: none;
  cursor: pointer;
  display: none;
}

.image-item:hover .delete-btn {
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 富文本编辑器容器 */
.editor-container {
  min-height: 300px;
}

/* 广告位卡片 */
.ad-card {
  background-color: var(--card-bg);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 16px;
  box-shadow: var(--shadow);
}

.ad-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.ad-card-title {
  font-size: 16px;
  font-weight: 600;
}

.ad-position {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.position-item {
  padding: 8px 16px;
  border-radius: 8px;
  background-color: #F5F5F5;
  cursor: pointer;
  transition: all 0.3s;
}

.position-item.active {
  background-color: var(--primary-color);
  color: #FFFFFF;
}

/* 开关 */
.switch {
  position: relative;
  width: 48px;
  height: 24px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.switch-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #ccc;
  transition: 0.3s;
  border-radius: 24px;
}

.switch-slider:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: 0.3s;
  border-radius: 50%;
}

.switch input:checked + .switch-slider {
  background-color: var(--primary-color);
}

.switch input:checked + .switch-slider:before {
  transform: translateX(24px);
}

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

.empty-state i {
  font-size: 64px;
  margin-bottom: 16px;
  opacity: 0.5;
}

.empty-state p {
  font-size: 16px;
}

/* 分页 */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-top: 24px;
}

.pagination button {
  padding: 8px 16px;
  border: 1px solid var(--border-color);
  background-color: var(--card-bg);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s;
}

.pagination button:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
}

.pagination button.active {
  background-color: var(--primary-color);
  border-color: var(--primary-color);
  color: #FFFFFF;
}

.pagination button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* 搜索栏 */
.search-bar {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
}

.search-bar .form-input {
  max-width: 300px;
}

/* 响应式 */
@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
  }
  
  .sidebar.show {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
  }
  
  .menu-toggle {
    display: block;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
}