contact form 7 : styling different-sized input text fields

Hi,

I have the following in my theme’s style.css:

input.wpcf7-text{
width:425px;
height:20px;
}

It works great.

But I want to have another (smaller-sized) input text field for the zip code (e.g.):

input.wpcf7-text-alt{
width:225px;
height:20px;
}

It doesn’t work though.

Does anyone know how I might style my input text fields differently?

Thanks in advance.