Hello,

Sorry for the late reply.
-To change the menu background, please add this code into your custom css box:

.extra_navigation {
    background: rgba(0, 0, 0, 0.72);
}

Edit the color to your wish.
-For the font color and size, add this code:

.extra_navigation ul li a {
    color: #ECF1F1;
    font-size: 15px;
}
.textwidget {
    color: #E6E4E4;
    font-size: 15px;
}

Best regards!

Hello,

Please replace it with this code and try again:

.open_extra_nav .extra_navigation.right {
    background-color: rgba(29, 28, 28, 0.35) !important;
}

Let me know.

Best regards!