Workflow form elements height (textbox/autocomplete box)

I am experimenting with workflows in the HTML5 v1.1 viewer. Is there a way to control the height of a textbox or autocomplete box? I can use the textarea element instead of textbox to specify a height, but can't change the autocomplete. The default height makes it hard to select the right input box with a fat finger in a mobile phone interface. Maybe there's a way to change the padding/margins around the elements to make the target area larger?