BuddyPress.org

Nvm turned out I had a /* on one of the lines in my style.css preventing any changes.
I changed up the code as well.

form#whats-new-form {
    border-style: solid;
    border-color: #82E0AA;
    border-width: 5px;
    padding: 10px 15px;
}

Carsten double check your code and previous code.