/* ============ 后台管理样式 ============ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: #f5f7fa;
  color: #333;
}

.admin-layout {
  display: flex;
  min-height: 100vh;
}

/* ============ 侧边栏 ============ */
.sidebar {
  width: 240px;
  background: #1a1a2e;
  color: #fff;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  overflow-y: auto;
  z-index: 100;
}

.logo {
  padding: 20px;
  font-size: 18px;
  font-weight: bold;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.logo i {
  color: #e74c3c;
  margin-right: 8px;
}

.nav-menu {
  padding: 10px 0;
}

.nav-item {
  display: flex;
  align-items: center;
  padding: 14px 20px;
  color: #a0a0b0;
  text-decoration: none;
  transition: all 0.2s;
  border-left: 3px solid transparent;
}

.nav-item:hover {
  background: rgba(255,255,255,0.05);
  color: #fff;
}

.nav-item.active {
  background: rgba(231, 76, 60, 0.1);
  color: #fff;
  border-left-color: #e74c3c;
}

.nav-item i {
  width: 20px;
  margin-right: 12px;
  text-align: center;
}

/* ============ 主内容区 ============ */
.main {
  flex: 1;
  margin-left: 240px;
}

.topbar {
  background: #fff;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar h2 {
  font-size: 18px;
  font-weight: 600;
}

.btn-link {
  color: #e74c3c;
  text-decoration: none;
  font-size: 14px;
}

.content {
  padding: 24px;
}

/* ============ 仪表盘 ============ */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.stat-card {
  background: #fff;
  border-radius: 12px;
  padding: 24px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.stat-card .icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  margin-bottom: 16px;
}

.stat-card .icon.blue { background: #e3f2fd; color: #1976d2; }
.stat-card .icon.green { background: #e8f5e9; color: #388e3c; }
.stat-card .icon.orange { background: #fff3e0; color: #f57c00; }
.stat-card .icon.purple { background: #f3e5f5; color: #7b1fa2; }
.stat-card .icon.red { background: #fce4ec; color: #c62828; }

.stat-card .value {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 4px;
}

.stat-card .label {
  font-size: 14px;
  color: #666;
}

/* ============ 表格 ============ */
.table-container {
  background: #fff;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.table-header {
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid #eee;
}

.table-header h3 {
  font-size: 16px;
  font-weight: 600;
}

.btn {
  padding: 8px 16px;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.btn-primary {
  background: #e74c3c;
  color: #fff;
}

.btn-primary:hover {
  background: #c0392b;
}

.btn-secondary {
  background: #f0f0f0;
  color: #333;
}

.btn-secondary:hover {
  background: #e0e0e0;
}

.btn-danger {
  background: #fff;
  color: #e74c3c;
  border: 1px solid #e74c3c;
}

.btn-danger:hover {
  background: #e74c3c;
  color: #fff;
}

.btn-sm {
  padding: 4px 10px;
  font-size: 12px;
}

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

th, td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid #f0f0f0;
}

th {
  font-weight: 600;
  font-size: 13px;
  color: #666;
  background: #fafafa;
}

td {
  font-size: 14px;
}

tr:last-child td {
  border-bottom: none;
}

tr:hover {
  background: #f9f9f9;
}

.cover-thumb {
  width: 40px;
  height: 40px;
  border-radius: 6px;
  object-fit: cover;
  background: #f0f0f0;
}

.actions-cell {
  display: flex;
  gap: 8px;
}

/* ============ 模态框 ============ */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0.5);
}

.modal-content {
  position: relative;
  background: #fff;
  border-radius: 12px;
  width: 90%;
  max-width: 560px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 20px 60px rgba(0,0,0,0.2);
}

.modal-header {
  padding: 16px 20px;
  border-bottom: 1px solid #eee;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-header h3 {
  font-size: 16px;
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  font-size: 18px;
  cursor: pointer;
  color: #666;
}

.modal-body {
  padding: 20px;
}

/* ============ 表单 ============ */
.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 6px;
  color: #333;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid #ddd;
  border-radius: 6px;
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: #e74c3c;
}

.form-group textarea {
  min-height: 100px;
  resize: vertical;
}

.form-group .file-upload {
  position: relative;
  display: inline-block;
}

.form-group .file-upload input[type="file"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.form-group .file-upload label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: #f0f0f0;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
}

.form-group .file-upload label:hover {
  background: #e0e0e0;
}

.form-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid #eee;
}

/* ============ 空状态 ============ */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: #999;
}

.empty-state i {
  font-size: 48px;
  margin-bottom: 16px;
  color: #ddd;
}

.empty-state p {
  font-size: 14px;
}

/* ============ 响应式 ============ */
@media (max-width: 768px) {
  .sidebar {
    width: 60px;
  }
  
  .sidebar .logo {
    font-size: 0;
    padding: 16px;
    text-align: center;
  }
  
  .sidebar .logo i {
    font-size: 20px;
  }
  
  .sidebar .nav-item span {
    display: none;
  }
  
  .sidebar .nav-item {
    justify-content: center;
    padding: 14px;
  }
  
  .sidebar .nav-item i {
    margin: 0;
  }
  
  .main {
    margin-left: 60px;
  }
  
  .content {
    padding: 16px;
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }
  
  .stat-card {
    padding: 16px;
  }
  
  .stat-card .value {
    font-size: 22px;
  }
  
  /* 表格横向滚动 */
  .table-container {
    overflow-x: auto;
  }
  
  table {
    min-width: 600px;
  }
}

@media (max-width: 480px) {
  .stats-grid {
    grid-template-columns: 1fr;
  }
}

/* ============ 通知 ============ */
.toast {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 12px 20px;
  border-radius: 8px;
  color: #fff;
  font-size: 14px;
  z-index: 2000;
  animation: slideIn 0.3s ease;
}

.toast.success { background: #27ae60; }
.toast.error { background: #e74c3c; }
.toast.info { background: #3498db; }

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}