In the contact_styled.php page, the CSS that controls the text fields looks like this:
<style type="text/css">
Label {text-transform:uppercase;background:#f9f1e1;padding:3px;}
.inputValue {width:85%;}
.inputText {width:85%; height:180px;}
.inputButton {}
.textfieldServerError {
display:block;
margin:0px;
color:#CC3333;
border: 1px solid #CC3333;
}
</style>
You would have to change the width on the inputValue to get the width of the text fields to change. This will change the width on all the text fields. If you want to set the width of a specific text field, you would set the width on that text field specifically, either by hard coding it into the field or setting up a CSS class for it.