.np-crypto-button {
            display: inline-block;
            padding: 12px 24px;
            background-color: #1a73e8;
            color: white;
            text-decoration: none;
            border-radius: 4px;
            font-weight: bold;
            transition: background-color 0.3s;
        }
        
        .np-crypto-button:hover {
            background-color: #155ab6;
        }
        
        .np-crypto-payment .error {
            color: #d32f2f;
            background-color: #ffebee;
            padding: 10px;
            border-left: 4px solid #d32f2f;
            margin: 15px 0;
        }