* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', system-ui, sans-serif;
        }

        body {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            padding: 20px;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
        }

        .header {
            text-align: center;
            margin-bottom: 40px;
            color: white;
        }

        .header h1 {
            font-size: 2.8rem;
            margin-bottom: 10px;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
        }

        .header p {
            font-size: 1.2rem;
            opacity: 0.9;
        }

        .dashboard {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 30px;
            margin-bottom: 30px;
        }

        @media (max-width: 900px) {
            .dashboard {
                grid-template-columns: 1fr;
            }
        }

        .card {
            background: white;
            border-radius: 15px;
            padding: 30px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.2);
            transition: transform 0.3s ease;
        }

        .card:hover {
            transform: translateY(-5px);
        }

        .card h2 {
            color: #333;
            margin-bottom: 20px;
            font-size: 1.5rem;
            border-bottom: 2px solid #667eea;
            padding-bottom: 10px;
        }

        .input-group {
            margin-bottom: 20px;
        }

        .input-group label {
            display: block;
            margin-bottom: 8px;
            color: #555;
            font-weight: 500;
        }

        .input-group input,
        .input-group select {
            width: 100%;
            padding: 12px 15px;
            border: 2px solid #e0e0e0;
            border-radius: 8px;
            font-size: 1rem;
            transition: border-color 0.3s;
        }

        .input-group input:focus,
        .input-group select:focus {
            outline: none;
            border-color: #667eea;
        }

        .btn {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            padding: 12px 25px;
            border-radius: 8px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }

        .btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
        }

        .btn-secondary {
            background: #6c757d;
        }

        .btn-success {
            background: #28a745;
        }

        .btn-danger {
            background: #dc3545;
        }

        .btn-sm {
            padding: 6px 12px;
            font-size: 0.9rem;
        }

        .members-list {
            list-style: none;
            max-height: 200px;
            overflow-y: auto;
            margin-bottom: 20px;
            border: 1px solid #eee;
            border-radius: 8px;
            padding: 10px;
        }

        .members-list li {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 10px 15px;
            background: #f8f9fa;
            margin-bottom: 8px;
            border-radius: 6px;
        }

        .members-list li:last-child {
            margin-bottom: 0;
        }

        .expense-item {
            background: #f8f9fa;
            padding: 15px;
            border-radius: 8px;
            margin-bottom: 15px;
            border-left: 4px solid #667eea;
        }

        .expense-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 10px;
        }

        .expense-title {
            font-weight: 600;
            color: #333;
            font-size: 1.1rem;
        }

        .expense-amount {
            font-weight: 700;
            color: #28a745;
            font-size: 1.2rem;
        }

        .expense-details {
            color: #666;
            font-size: 0.9rem;
            display: flex;
            justify-content: space-between;
        }

        .split-badge {
            background: #e9ecef;
            color: #495057;
            padding: 3px 8px;
            border-radius: 12px;
            font-size: 0.8rem;
            margin-top: 5px;
        }

        .balance-summary {
            background: #A7AAE1;
            color: white;
            padding: 20px;
            border-radius: 10px;
            margin-top: 20px;
        }

        .balance-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 10px 0;
            border-bottom: 1px solid rgba(255,255,255,0.1);
        }

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

        .positive {
            color: #006400;
            font-weight: 600;
        }

        .negative {
            color: #dc3545;
            font-weight: 600;
        }

        .settlement {
            background: #fff3cd;
            border-left: 4px solid #ffc107;
            padding: 15px;
            margin-top: 15px;
            border-radius: 6px;
        }

        .modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0,0,0,0.5);
            justify-content: center;
            align-items: center;
            z-index: 1000;
        }

        .modal-content {
            background: white;
            padding: 30px;
            border-radius: 15px;
            max-width: 500px;
            width: 90%;
            max-height: 90vh;
            overflow-y: auto;
        }

        .modal-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 20px;
        }

        .modal-title {
            font-size: 1.5rem;
            color: #333;
        }

        .close-btn {
            background: none;
            border: none;
            font-size: 1.5rem;
            cursor: pointer;
            color: #666;
        }

        .checkbox-group {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 10px;
            margin: 15px 0;
        }

        .checkbox-item {
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .checkbox-item input[type="checkbox"] {
            width: auto;
        }

        .alert {
            padding: 12px 15px;
            border-radius: 8px;
            margin: 15px 0;
            display: none;
        }

        .alert-success {
            background: #d4edda;
            color: #155724;
            border: 1px solid #c3e6cb;
        }

        .alert-danger {
            background: #f8d7da;
            color: #721c24;
            border: 1px solid #f5c6cb;
        }

        .empty-state {
            text-align: center;
            padding: 40px 20px;
            color: #666;
        }

        .empty-state i {
            font-size: 3rem;
            margin-bottom: 15px;
            opacity: 0.3;
        }

        .tabs {
            display: flex;
            gap: 5px;
            margin-bottom: 20px;
            border-bottom: 2px solid #e0e0e0;
        }

        .tab {
            padding: 10px 20px;
            background: none;
            border: none;
            cursor: pointer;
            font-weight: 500;
            color: #666;
            position: relative;
        }

        .tab.active {
            color: #667eea;
        }

        .tab.active::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            right: 0;
            height: 2px;
            background: #667eea;
        }

        .tab-content {
            display: none;
        }

        .tab-content.active {
            display: block;
        }

        .stats {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 15px;
            margin-bottom: 20px;
        }

        .stat-card {
            background: #f8f9fa;
            padding: 15px;
            border-radius: 10px;
            text-align: center;
        }

        .stat-value {
            font-size: 1.8rem;
            font-weight: 700;
            color: #667eea;
            margin-bottom: 5px;
        }

        .stat-label {
            font-size: 0.9rem;
            color: #666;
        }