How to change the font and size of text inside a drop[ down box?

Hi in my form ,

i would like to change the font similar to the font of other fields in the form

Arial with size 13

how it could be done?

now it looks not good

There's actually an option to change your entire form font at your top toolbar under Form Style.

But if that is not working then you can override everything on the entire form font with some injected css coding. An example of a css code which would do this is -

CSS:  .form-all {font-family: Impact; Helvetica; Verdana;}

Live Form:  http://form.jotform.us/form/41904645246153

Result:  

However, please note that if you are using any widgets then this might not work unless the widget has an option to inject css into it as well because of the fact that the widgets are self-contained within their own iFrames which tends to ignore the original form css if any is applied.