I want to increase the length of the text boxes in the Dynamic text box

I want to increase the length of the text boxes in the Dynamic text box widget. I assume it could be done via custom CSS code. Please explain the process and code for doing this.

You can handle the fields in the widget with the class ".dynamicField", example: 

.dynamicField {

    width: 100px !important;

    height: 10px !important;

}

This will affect all the fields added, this guide will help you injecting the code to the widget: https://www.jotform.com/help/428-How-to-Inject-CSS-Codes-to-Widgets 

Kindly note that you may change the values "100px" or add any specific CSS rule you need to the code.