how to customize the textboxes size in a Configurable List Widget?

You have to use a custom CSS codes and target the specific textbox field in the widget. We can help you with the custom CSS codes, but we'd suggest creating the final form first. This way, we ca have you the final custom CSS codes as well. Don't forget to let us know the widget field name.

Thanks 

Hi thanks for your reply ,

could you please send the css code to change the button colour in ADD and Remove to black colour

Hi there, 

Here's a sample CSS in order to change the styling of the "add" button:

.add {
    background: white;
    border: 1px solid green;
    color: green;
    padding:3px 15px;
    margin-top:12px;
}

Which will result in the following style:

If there's a specific style you want to have, please let us know and we'll come up with the relevant css for you.

Thanks.