CSS to increase width of phone entry box

I would like to slightly increase the width of the phone number box - so it can accommodate a full 7 digits plus the dash separator. So far, my attempts have increased both the area code and the phone number box width. I only want to increase the phone number input box.

Thank you 

I've tried:

}

#input_6_phone {

width: 100px !important;

}

and 

}

#input_6_phone {

 width: 100px;

}

Thank you

Hi DocEastin,

We are happy to hear that you solved your problem. Please feel free to contact us if you need any further assistance.

Thank you.

Never mind. Finally figured it out using the advanced CSS function - pretty slick:

#input_6_phone {

    width : 73px;

}