Change button padding in Contact Form element

Team, I am trying to change the padding of a button. I can change the background and border radius but the padding is not working.

Same here:

I am simply using on the child theme.

#top .round-submit .button {

background: transparent;
border: 4px solid whitesmoke;
border-radius: 20px;
font-size:16px;
padding: 10px;

}