text box line spacing

Your questions seems to have been posted a little early, mentioning only "text box line spacing". Can you please provide a little more information about your query?

If you are looking to modify the spacing between each of your form fields, please open your form in the Designer and under Line Layout, try changing the Line Spacing and Vertical Padding values to match your needs:

If you are instead looking to change only the spacing inside Text Box fields on your form, I see that this is how they currently appear:

You can change the padding of these fields by adding a bit of custom CSS to your form - at the moment, the theme you are using is applying a padding of 8 pixels to these fields. If you were looking to reduce the padding, you can try using CSS such as this:

.form-textbox { padding: 4px; }

In the designer, simply switch to the CSS tab and paste the code there. Your form would appear like this:

If you were looking for something else, please provide a little more information about what it is you are looking for, and we'll be happy to help.