Text box w/ label taking two lines instead of one

preview in "designer" shows them on one line in mobilephone preview. on my iphone 6 the take up two lines - nee compact display

If I understood you correctly you are referring to the behavior that on mobile, form looks like on picture below. That is normal behavior because your responsive mode is enabled.  

If you want that your form looks like on picture below, you can Inject Custom CSS.

To do that inside of your Form Builder select Setup & Embed tab, then click on Preferences, then select Form Styles tab and inside of Inject Custom CSS field at the bottom of existing code paste this code:

@media screen and (max-width: 480px), screen and (max-device-width: 768px) and (orientation: portrait), screen and (max-device-width: 415px) and (orientation: landscape){

    .form-label {

        width : 50px!important;

    }

    .form-input, .form-textbox {

        max-width : 50px !important;

    }

    #input_30 {

        max-width : 100px !important;

    }

    #header_1 {

    max-width : 100% !important;

}

}

Here is my form: http://form.jotformpro.com/form/52412678171960? 

Please be free to clone it.

If I did not understood you correctly please explain in more details what you are trying to achieve.

Hope this will help. Let us know if you need further assistance.