/* 管理后台样式 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: #f5f5f5; }
.sidebar { background: #2c3e50; min-height: 100vh; color: white; padding: 20px; width: 250px; position: fixed; left: 0; top: 0; }
.main-content { margin-left: 250px; padding: 20px; }
.card { background: white; border-radius: 8px; padding: 20px; margin-bottom: 20px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 30px; }
.stat-card { background: white; border-radius: 8px; padding: 20px; text-align: center; box-shadow: 0 2px 4px rgba(0,0,0,0.1); }
.stat-number { font-size: 32px; font-weight: bold; color: #3498db; margin: 10px 0; }
.stat-label { color: #7f8c8d; font-size: 14px; }
.nav-link { color: white; text-decoration: none; display: block; padding: 10px 15px; margin: 5px 0; border-radius: 4px; }
.nav-link:hover { background: rgba(255,255,255,0.1); }
table { width: 100%; border-collapse: collapse; background: white; border-radius: 8px; overflow: hidden; box-shadow: 0 2px 4px rgba(0,0,0,0.1); }
th, td { padding: 12px 15px; text-align: left; border-bottom: 1px solid #ecf0f1; }
th { background: #34495e; color: white; }
tr:hover { background: #f8f9fa; }
.alert { padding: 12px 20px; border-radius: 4px; margin-bottom: 20px; }
.alert-info { background: #d1ecf1; color: #0c5460; }
.alert-warning { background: #fff3cd; color: #856404; }
.form-control { width: 100%; padding: 10px 15px; border: 1px solid #ddd; border-radius: 4px; font-size: 14px; margin-bottom: 15px; }
.btn { padding: 10px 20px; border: none; border-radius: 4px; cursor: pointer; font-size: 14px; }
.btn-primary { background: #3498db; color: white; }
.logout-btn { background: transparent; border: 1px solid rgba(255,255,255,0.3); color: white; width: 100%; margin-top: 20px; padding: 10px; border-radius: 4px; cursor: pointer; }