* 

body {
    font-size: 18px; 
    overflow-x: hidden;
}

        

        .calculator-card {
            background-color: white;
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            padding: 30px;
            margin-bottom: 30px;
        }

        .form-group {
            margin-bottom: 25px;
        }

        .form-group label {
            display: block;
            margin-bottom: 10px;
            font-weight: 600;
            color: #2c3e50;
            font-size: 1.1rem;
        }

        .input-row {
            display: flex;
            gap: 15px;
            align-items: center;
        }

        .input-with-label {
            flex: 1;
        }

        .input-with-label span {
            display: block;
            margin-bottom: 5px;
            color: #7f8c8d;
            font-size: 0.9rem;
        }

        input, select {
            width: 100%;
            box-sizing: border-box;
            padding: 12px;
            border: 1px solid #d1d5db;
            border-radius: 6px;
            font-size: 16px;
        }

        input:focus, select:focus {
            outline: none;
            border-color: #3498db;
            box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
        }

        .form-actions {
            display: flex;
            gap: 15px;
            margin-top: 30px;
        }

        .btn {
            padding: 14px 28px;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-weight: 600;
            font-size: 16px;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            flex: 1;
        }

        .btn-primary {
            background-color: #3498db;
            color: white;
        }

        .btn-primary:hover {
            background-color: #2980b9;
        }

        .btn-secondary {
            background-color: #95a5a6;
            color: white;
        }

        .btn-secondary:hover {
            background-color: #7f8c8d;
        }

        .result-card {
            background-color: white;
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            padding: 30px;
            text-align: center;
            margin-top: 30px;
            display: none;
        }

        .result-card.show {
            display: block;
            animation: fadeIn 0.5s ease;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .result-title {
            color: #2c3e50;
            margin-bottom: 15px;
            font-size: 1.3rem;
        }

        .result-value {
            font-size: 2.8rem;
            font-weight: bold;
            color: #2c3e50;
            margin: 20px 0;
        }

        .result-grade {
            font-size: 3rem;
            font-weight: bold;
            margin: 20px 0;
            color: #2ecc71;
        }

        .result-description {
            color: #7f8c8d;
            font-size: 1rem;
            margin-top: 10px;
        }

        .grade-system-selector {
            background: #f8f9fa;
            border-radius: 10px;
            padding: 15px;
            margin-bottom: 20px;
            border: 1px solid #e5e7eb;
        }

        .grade-system-selector label {
            font-weight: 600;
            margin-right: 10px;
            color: #2c3e50;
        }

        .grade-system-selector select {
            padding: 8px 15px;
            border-radius: 6px;
            border: 1px solid #d1d5db;
            font-size: 16px;
            width: 250px;
        }

        .percentage-input-container {
            position: relative;
        }

        .percentage-input-container::after {
            content: "%";
            position: absolute;
            right: 12px;
            top: 50%;
            transform: translateY(-50%);
            color: #7f8c8d;
            font-weight: 600;
        }

        .percentage-input-container input {
            padding-right: 30px;
        }

        /* Responsive styles */
        @media (max-width: 650px) {
            .input-row {
                flex-direction: column;
                gap: 10px;
            }
            
            .input-with-label {
                width: 100%;
            }
            
            .form-actions {
                flex-direction: column;
            }
            
            .btn {
                width: 100%;
            }
            
            .grade-system-selector select {
                width: 100%;
            }
            
            .result-value {
                font-size: 2.2rem;
            }
            
            .result-grade {
                font-size: 2.5rem;
            }
        }