I would like the text box for the hidden field

i would like the text box for the hidden field, I observed a presentation taught by, to have that little white intent line like the other boxes have

I am not sure if I understand your query correctly. Do you want to have a text box field hidden on your form or are you referring to the line below the text box on the form? Could you provide us with more information on your requirement so that we can provide you with necessary assistance?

We will wait for your response. Thank you! 

i'm not sure how to describe it. on most of the text boxes, it looks like
the box for where the text should be entered and the little label below it
is slightly intended inward. so there is a super thin white line to the
right and bottom of the box and a super thin grey line on the top and left.
however, i have two boxes that are conditional, and one of them is a text
box titled, i observed presentations taught by, that's text box is to the
right of the longer question and i want it to have those thin lines around
it, so that the box where you type the response is easier to see.
does that help?
you first have to mark " Yes, I've observed 3 LYRIC presentations." to see
the box i'm referring to.
...

You have to inject the following custom CSS codes to do that:

textarea#input_15 {

    border: 1px inset !important;

    padding-left: 3px;

}

.form-textarea-limit-indicator {

    border-left: 1px inset;

    border-right: 1px inset;

    padding-top: 5px;

    margin-top: -5px;

    color: #fff;

}

Here's how to inject: https://www.jotform.com/help/117-How-to-Inject-Custom-CSS-Codes.