CSS PAN Textbox Focus

I am trying to implement hosted tokenization using the guide from:
https://developer.moneris.com/Documentation/NA/E-Commerce%20Solutions/Hosted%20Solutions/Hosted%20Tokenization

Question, how can I customize the 'focus' css event on css_textbox_pan? 

Expected result in the iframe <head>:

.monerisInput:focus {
    display:block;
    border-color:rgb(0,167,88);
    border-radius:0;
    outline-style:none;
}