* {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        body {
            background-color: #f3f4f6;
            color: #1f2937;
            padding: 20px;
        }
        .container {
            max-width: 1000px;
            margin: 0 auto;
            background-color: white;
            border-radius: 10px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            padding: 20px;
        }
        header {
            text-align: center;
            margin-bottom: 30px;
            padding-bottom: 20px;
            border-bottom: 1px solid #e5e7eb;
        }
        h1 {
            color: #3b82f6;
            margin-bottom: 10px;
        }
        .balance-card {
            background: linear-gradient(135deg, #3b82f6, #1d4ed8);
            color: white;
            border-radius: 10px;
            padding: 20px;
            margin-bottom: 20px;
            text-align: center;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        }
        .balance-card h2 {
            font-size: 1.2rem;
            margin-bottom: 10px;
        }
        .balance-amount {
            font-size: 2rem;
            font-weight: bold;
        }
        .summary {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 15px;
            margin-bottom: 20px;
        }
        .income-card, .expense-card {
            padding: 8px;
            border-radius: 10px;
            text-align: center;
        }
        .income-card {
            background-color: #dcfce7;
            color: #166534;
        }
        .expense-card {
            background-color: #fee2e2;
            color: #991b1b;
        }
        .form-container {
            background-color: #f9fafb;
            padding: 20px;
            border-radius: 10px;
            margin-bottom: 20px;
        }
        .form-group {
            margin-bottom: 15px;
        }
        label {
            display: block;
            margin-bottom: 5px;
            font-weight: 500;
        }
        input, select {
            width: 100%;
            padding: 10px;
            border: 1px solid #d1d5db;
            border-radius: 5px;
            font-size: 1rem;
        }
        button {
            background-color: #3b82f6;
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 5px;
            cursor: pointer;
            font-size: 1rem;
            font-weight: 500;
            transition: background-color 0.2s;
        }
        button:hover {
            background-color: #2563eb;
        }
        .transactions {
            margin-bottom: 20px;
        }
        .transaction-item {
            display: flex;
            justify-content: space-between;
            padding: 15px;
            border-bottom: 1px solid #e5e7eb;
            align-items: center;
        }
        .transaction-item:last-child {
            border-bottom: none;
        }
        .transaction-income {
            border-left: 4px solid #34d399;
        }
        .transaction-expense {
            border-left: 4px solid #f87171;
        }
        .transaction-desc {
            flex-grow: 1;
        }
        .transaction-amount {
            font-weight: 500;
            margin-right: 15px;
        }
        .transaction-income .transaction-amount {
            color: #166534;
        }
        .transaction-expense .transaction-amount {
            color: #991b1b;
        }
        .delete-btn {
            background-color: #ef4444;
            color: white;
            border: none;
            padding: 5px 10px;
            border-radius: 5px;
            cursor: pointer;
        }
        .delete-btn:hover {
            background-color: #dc2626;
        }
        .chart-container {
            background-color: white;
            padding: 20px;
            border-radius: 10px;
            max-width: 600px;
        }
        .empty-state {
            text-align: center;
            padding: 30px;
            color: #6b7280;
        }
        
        @media (min-width: 768px) {
            .main-content {
                display: grid;
                grid-template-columns: 1fr 1fr;
                gap: 20px;
            }
            .chart-container {
                grid-column: span 2;
            }
        }