Child Theme css to match Parent Menu

https://www.stevewongorthodontics.com/wp/index.php/toms-car-care/

How do I edit the css in my child theme to match the way my main menu looks in the header? I don’t want underlines, and I want it to go across the entire width, with a drop down showing for 2 of the items. Here is the css I have in my child theme:\

#footerMenu {
border-top: none;
}

#footerMenu li {
text-align: justify;
padding-left: 1em;
padding-bottom: .4em;
padding-right: 2em;
padding-top: .4em;
font-size: 12px;
display: inline;
text-decoration: none;
font-style: normal;
}

#footerMenu ul {
list-style: none;
margin: 0 35px;
padding: 0;
}

#footerMenu a:focus, a:active, {
text-decoration: none;
}

#footerMenu a:hover {
color: #333333;
}

thanks!