* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, "Microsoft YaHei", sans-serif; background: #f5f7fa; color: #333; }
a { text-decoration: none; color: inherit; }

/* 登录页 */
.login-wrap { min-height: 100vh; display: flex; align-items: center; justify-content: center; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); }
.login-box { background: #fff; padding: 40px; border-radius: 12px; box-shadow: 0 20px 60px rgba(0,0,0,.15); width: 380px; }
.login-box h2 { text-align: center; margin-bottom: 30px; color: #333; }
.login-box .form-group { margin-bottom: 20px; }
.login-box label { display: block; margin-bottom: 8px; font-size: 14px; color: #666; }
.login-box input { width: 100%; padding: 12px 15px; border: 1px solid #ddd; border-radius: 8px; font-size: 14px; outline: none; transition: border .3s; }
.login-box input:focus { border-color: #667eea; }
.login-box .btn { width: 100%; padding: 12px; background: linear-gradient(135deg, #667eea, #764ba2); color: #fff; border: none; border-radius: 8px; font-size: 16px; cursor: pointer; }
.login-box .error { color: #e74c3c; text-align: center; margin-bottom: 15px; font-size: 14px; }

/* 后台布局 */
.layout { display: flex; min-height: 100vh; }
.sidebar { width: 220px; background: #2c3e50; color: #ecf0f1; padding: 20px 0; position: fixed; height: 100vh; overflow-y: auto; }
.sidebar .logo { padding: 0 20px 20px; font-size: 18px; font-weight: bold; border-bottom: 1px solid #34495e; margin-bottom: 10px; }
.sidebar a { display: block; padding: 12px 20px; color: #bdc3c7; font-size: 14px; transition: all .2s; }
.sidebar a:hover, .sidebar a.active { background: #34495e; color: #fff; border-left: 3px solid #667eea; }
.main { flex: 1; margin-left: 220px; padding: 20px; }
.topbar { background: #fff; padding: 15px 25px; border-radius: 8px; margin-bottom: 20px; display: flex; justify-content: space-between; align-items: center; box-shadow: 0 2px 8px rgba(0,0,0,.05); }
.topbar .page-title { font-size: 18px; font-weight: 600; }
.topbar .user-info { font-size: 14px; color: #666; }
.topbar .user-info a { color: #667eea; margin-left: 15px; }

/* 卡片 */
.card { background: #fff; border-radius: 8px; padding: 20px; margin-bottom: 20px; box-shadow: 0 2px 8px rgba(0,0,0,.05); }
.card h3 { margin-bottom: 15px; font-size: 16px; }

/* 统计卡片 */
.stats-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 15px; margin-bottom: 20px; }
.stat-card { background: #fff; border-radius: 8px; padding: 20px; text-align: center; box-shadow: 0 2px 8px rgba(0,0,0,.05); }
.stat-card .num { font-size: 28px; font-weight: bold; color: #667eea; }
.stat-card .label { font-size: 13px; color: #999; margin-top: 5px; }

/* 表格 */
table { width: 100%; border-collapse: collapse; }
th, td { padding: 12px 15px; text-align: left; border-bottom: 1px solid #eee; font-size: 14px; }
th { background: #f8f9fa; font-weight: 600; color: #555; }
tr:hover { background: #f8f9fa; }
.table-img { width: 50px; height: 50px; object-fit: cover; border-radius: 4px; }

/* 按钮 */
.btn { display: inline-block; padding: 8px 18px; border-radius: 6px; font-size: 14px; cursor: pointer; border: none; transition: all .2s; }
.btn-primary { background: #667eea; color: #fff; }
.btn-primary:hover { background: #5568d3; }
.btn-danger { background: #e74c3c; color: #fff; }
.btn-danger:hover { background: #c0392b; }
.btn-default { background: #ecf0f1; color: #555; }
.btn-default:hover { background: #dfe6e9; }
.btn-sm { padding: 5px 12px; font-size: 12px; }

/* 表单 */
.form-group { margin-bottom: 18px; }
.form-group label { display: block; margin-bottom: 6px; font-size: 14px; color: #555; font-weight: 500; }
.form-group input[type="text"], .form-group input[type="number"], .form-group input[type="password"], .form-group select, .form-group textarea {
  width: 100%; padding: 10px 12px; border: 1px solid #ddd; border-radius: 6px; font-size: 14px; outline: none;
}
.form-group textarea { min-height: 100px; resize: vertical; }
.form-group input:focus, .form-group select:focus, .form-group textarea:focus { border-color: #667eea; }
.form-row { display: flex; gap: 15px; }
.form-row .form-group { flex: 1; }
.form-group .checkbox-group { display: flex; align-items: center; gap: 8px; }
.form-group .checkbox-group input { width: auto; }

/* 搜索栏 */
.search-bar { display: flex; gap: 10px; margin-bottom: 15px; align-items: center; }
.search-bar input, .search-bar select { padding: 8px 12px; border: 1px solid #ddd; border-radius: 6px; font-size: 14px; }

/* 分页 */
.pagination { display: flex; gap: 8px; justify-content: center; margin-top: 20px; }
.pagination a, .pagination span { padding: 6px 12px; border: 1px solid #ddd; border-radius: 4px; font-size: 13px; color: #555; }
.pagination .current { background: #667eea; color: #fff; border-color: #667eea; }

/* 提示 */
.alert { padding: 12px 18px; border-radius: 6px; margin-bottom: 15px; font-size: 14px; }
.alert-success { background: #d4edda; color: #155724; }
.alert-error { background: #f8d7da; color: #721c24; }

/* 上传预览 */
.upload-preview { max-width: 200px; max-height: 200px; margin-top: 10px; border-radius: 6px; border: 1px solid #eee; }