* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        :root {
            --primary: #6366f1;
            --primary-dark: #4f46e5;
            --secondary: #10b981;
            --danger: #ef4444;
            --warning: #f59e0b;
            --dark: #0f172a;
            --dark-light: #1e293b;
            --gray: #64748b;
            --gray-light: #cbd5e1;
            --light: #f1f5f9;
            --white: #ffffff;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
            background: var(--light);
            color: var(--dark);
        }

        /* Sidebar */
        .sidebar {
            position: fixed;
            left: 0;
            top: 0;
            width: 260px;
            height: 100vh;
            background: var(--white);
            box-shadow: 2px 0 10px rgba(0, 0, 0, 0.05);
            padding: 2rem 0;
            overflow-y: auto;
            transition: transform 0.3s;
            z-index: 1000;
        }

        .logo {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--primary);
            padding: 0 1.5rem;
            margin-bottom: 2rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .menu {
            list-style: none;
        }

        .menu-item {
            padding: 0.75rem 1.5rem;
            margin: 0.25rem 0;
            cursor: pointer;
            transition: all 0.3s;
            display: flex;
            align-items: center;
            gap: 0.75rem;
            color: var(--gray);
            text-decoration: none;
        }

        .menu-item:hover, .menu-item.active {
            background: var(--light);
            color: var(--primary);
            border-right: 3px solid var(--primary);
        }

        .menu-icon {
            font-size: 1.25rem;
        }

        /* Main Content */
        .main-content {
            margin-left: 260px;
            padding: 2rem;
            min-height: 100vh;
        }

        /* Header */
        .header {
            background: var(--white);
            padding: 1.5rem 2rem;
            border-radius: 12px;
            margin-bottom: 2rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
        }

        .header-left h1 {
            font-size: 1.75rem;
            margin-bottom: 0.25rem;
        }

        .header-left p {
            color: var(--gray);
            font-size: 0.9rem;
        }

        .header-right {
            display: flex;
            gap: 1rem;
            align-items: center;
        }

        .user-info {
            text-align: right;
            margin-right: 1rem;
        }

        .user-name {
            font-weight: 600;
            font-size: 0.95rem;
        }

        .user-email {
            font-size: 0.8rem;
            color: var(--gray);
        }

        .user-avatar {
            width: 45px;
            height: 45px;
            border-radius: 50%;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--white);
            font-weight: 600;
            cursor: pointer;
        }

        .btn {
            padding: 0.75rem 1.5rem;
            border: none;
            border-radius: 8px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s;
            text-decoration: none;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
        }

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

        .btn-primary:hover {
            background: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
        }

        .btn-outline {
            background: transparent;
            border: 2px solid var(--primary);
            color: var(--primary);
        }

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

        /* Stats Grid */
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 1.5rem;
            margin-bottom: 2rem;
        }

        .stat-card {
            background: var(--white);
            padding: 1.5rem;
            border-radius: 12px;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
            transition: transform 0.3s, box-shadow 0.3s;
        }

        .stat-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
        }

        .stat-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
        }

        .stat-title {
            font-size: 0.875rem;
            color: var(--gray);
            font-weight: 500;
        }

        .stat-icon {
            width: 45px;
            height: 45px;
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
        }

        .stat-value {
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
        }

        .stat-subtitle {
            font-size: 0.875rem;
            color: var(--gray);
        }

        /* Dashboard Grid */
        .dashboard-grid {
            display: grid;
            grid-template-columns: 2fr 1fr;
            gap: 1.5rem;
            margin-bottom: 2rem;
        }

        .card {
            background: var(--white);
            padding: 1.5rem;
            border-radius: 12px;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
        }

        .card-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1.5rem;
            padding-bottom: 1rem;
            border-bottom: 1px solid var(--light);
        }

        .card-title {
            font-size: 1.25rem;
            font-weight: 600;
        }

        .card-action {
            color: var(--primary);
            font-size: 0.875rem;
            cursor: pointer;
            text-decoration: none;
        }

        /* Recent Transactions */
        .transaction-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 0;
            border-bottom: 1px solid var(--light);
        }

        .transaction-item:last-child {
            border-bottom: none;
        }

        .transaction-info {
            display: flex;
            align-items: center;
            gap: 1rem;
        }

        .transaction-avatar {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background: var(--light);
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 600;
            color: var(--primary);
            font-size: 0.9rem;
        }

        .transaction-details h4 {
            font-size: 0.95rem;
            margin-bottom: 0.25rem;
        }

        .transaction-details p {
            font-size: 0.8rem;
            color: var(--gray);
        }

        .transaction-amount {
            font-weight: 600;
            font-size: 1.1rem;
        }

        .transaction-amount.credit {
            color: var(--secondary);
        }

        .transaction-amount.payment {
            color: var(--danger);
        }

        /* Quick Actions */
        .quick-actions {
            display: grid;
            grid-template-columns: 1fr;
            gap: 1rem;
        }

        .action-btn {
            background: var(--light);
            padding: 1rem;
            border-radius: 10px;
            border: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 1rem;
            transition: all 0.3s;
            text-align: left;
        }

        .action-btn:hover {
            background: var(--primary);
            color: var(--white);
            transform: translateX(5px);
        }

        .action-icon {
            width: 45px;
            height: 45px;
            border-radius: 10px;
            background: var(--white);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
        }

        .action-btn:hover .action-icon {
            background: rgba(255, 255, 255, 0.2);
        }

        /* Customers Table */
        .customers-table {
            width: 100%;
            margin-top: 1rem;
        }

        .customers-table th {
            text-align: left;
            padding: 0.75rem;
            background: var(--light);
            font-weight: 600;
            font-size: 0.875rem;
            color: var(--gray);
        }

        .customers-table td {
            padding: 0.75rem;
            border-bottom: 1px solid var(--light);
        }

        .customers-table tr:hover {
            background: var(--light);
        }

        .badge {
            padding: 0.25rem 0.75rem;
            border-radius: 20px;
            font-size: 0.75rem;
            font-weight: 600;
        }

        .badge-success {
            background: #d1fae5;
            color: var(--secondary);
        }

        .badge-danger {
            background: #fee2e2;
            color: var(--danger);
        }

        .badge-warning {
            background: #fef3c7;
            color: var(--warning);
        }

        .badge-free {
            background: var(--gray-light);
            color: var(--gray);
        }

        /* Loading */
        .loading {
            text-align: center;
            padding: 3rem;
            color: var(--gray);
        }

        .spinner {
            border: 3px solid var(--light);
            border-top: 3px solid var(--primary);
            border-radius: 50%;
            width: 40px;
            height: 40px;
            animation: spin 1s linear infinite;
            margin: 0 auto 1rem;
        }

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

        .empty-state {
            text-align: center;
            padding: 3rem;
            color: var(--gray);
        }

        .empty-state-icon {
            font-size: 4rem;
            margin-bottom: 1rem;
        }

        /* Responsive */
        @media (max-width: 1024px) {
            .dashboard-grid {
                grid-template-columns: 1fr;
            }
            
            .stats-grid {
                grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            }
        }

        @media (max-width: 768px) {
            .sidebar {
                transform: translateX(-100%);
                box-shadow: 4px 0 20px rgba(0, 0, 0, 0.15);
            }

            .sidebar.open {
                transform: translateX(0);
            }

            .main-content {
                margin-left: 0;
                padding: 1rem;
                padding-top: 4rem;
            }

            .stats-grid {
                grid-template-columns: 1fr;
                gap: 1rem;
            }
            
            .stat-card {
                padding: 1rem;
            }
            
            .stat-value {
                font-size: 1.5rem;
            }
            
            .stat-icon {
                width: 40px;
                height: 40px;
                font-size: 1.25rem;
            }

            .header {
                flex-direction: row;
                gap: 0.5rem;
                padding: 1rem;
                align-items: center;
            }
            
            .header-left {
                flex: 1;
                min-width: 0;
            }
            
            .header-left h1 {
                font-size: 1.1rem;
                white-space: nowrap;
                overflow: hidden;
                text-overflow: ellipsis;
            }
            
            .header-left p {
                display: none;
            }
            
            .header-right {
                display: flex;
                gap: 0.5rem;
                align-items: center;
            }
            
            .user-info {
                display: none;
            }
            
            .user-avatar {
                width: 40px;
                height: 40px;
                font-size: 0.9rem;
            }
            
            .logout-btn {
                padding: 0.5rem 0.75rem;
                font-size: 0.8rem;
            }
            
            .card {
                padding: 1rem;
            }
            
            .card-title {
                font-size: 1rem;
            }
            
            .dashboard-grid {
                gap: 1rem;
            }
            
            .customers-table {
                font-size: 0.8rem;
                display: block;
                overflow-x: auto;
                -webkit-overflow-scrolling: touch;
            }
            
            .customers-table th,
            .customers-table td {
                padding: 0.5rem;
                white-space: nowrap;
            }

            .menu-toggle {
                display: block;
                position: fixed;
                top: 1rem;
                left: 1rem;
                z-index: 1001;
                background: var(--primary);
                color: white;
                border: none;
                padding: 0.75rem 1rem;
                border-radius: 8px;
                cursor: pointer;
                font-size: 1.25rem;
                box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
            }
        }
        
        @media (max-width: 480px) {
            .main-content {
                padding: 0.75rem;
                padding-top: 4rem;
            }
            
            .header {
                padding: 0.75rem;
            }
            
            .header-left h1 {
                font-size: 1rem;
            }
            
            .stats-grid {
                grid-template-columns: 1fr;
                gap: 0.75rem;
            }
            
            .stat-card {
                padding: 0.875rem;
            }
            
            .stat-value {
                font-size: 1.25rem;
            }
            
            .stat-title {
                font-size: 0.8rem;
            }
            
            .stat-subtitle {
                font-size: 0.75rem;
            }
            
            .transaction-item {
                padding: 0.75rem 0;
            }
            
            .transaction-avatar {
                width: 35px;
                height: 35px;
                font-size: 0.8rem;
            }
            
            .transaction-details h4 {
                font-size: 0.875rem;
            }
            
            .transaction-details p {
                font-size: 0.75rem;
            }
            
            .transaction-amount {
                font-size: 0.95rem;
            }
            
            .action-btn {
                padding: 0.875rem;
            }
            
            .customers-table {
                font-size: 0.75rem;
            }
        }

        .menu-toggle {
            display: none;
        }
        
        .logout-btn {
            background: var(--danger);
            color: var(--white);
            border: none;
            padding: 0.5rem 1rem;
            border-radius: 8px;
            cursor: pointer;
            font-weight: 600;
            font-size: 0.875rem;
            transition: all 0.3s;
        }
        
        .logout-btn:hover {
            background: #dc2626;
            transform: translateY(-2px);
        }