main menu underline on homepage

Ismael,
Thanks for your reply. I saved the Quick CSS above and there is no change. Underline still appearing. I did try clearing my cache first. Perhaps I have existing quick CSS that is preventing your code from taking effect? Here is what I have currently in my quick css:

.header_color .main_menu ul ul { background-color: transparent; color: black; }
.header_color .main_menu .menu ul li a { background-color: rgba(248,248,248,0.7); color: black; }

.header_bg {
opacity: 1;
}

.main_color div.hr span, .main_color div.hr {
border-color: blue;}

.html_header_top .header_color .main_menu ul:first-child >li > ul {
border-top: none;
}

Ismael,
I dont understand your instructions “please try to put it above the Quick CSS field”

Do you mean that the order of the quick css matters, and that I need to put this new css above my existing css?

If so, I tried that and see no change – the underlines are still there. Here is my entire Quick CSS as it is currently:

.html_header_top .header_color .main_menu ul:first-child >li > ul, .html_header_top #top .header_color .avia_mega_div > .sub-menu {
border-top: none !important;
}

body {
  font-size: 18px;
}

.header_color .main_menu ul ul { background-color: transparent; color: black; }
.header_color .main_menu .menu ul li a { background-color: rgba(248,248,248,0.7); color: black; }

.header_bg {
opacity: 1;
}

.main_color div.hr span, .main_color div.hr {
	border-color: blue;}

If that’s not what you mean, I am not sure how to place the CSS you provided “above the Quick CSS field’.
Thanks for your assistance

yes, that’s it exactly.
thanks, that did the trick