Hello,

1-Please add this code into your custom css box:

aside ul li#menu-item-523 {
    border-bottom: none;
}

2-Add this code:

 a:active {
    background-color: #3f77c7;
    color: white;
}

Change the styling to your wish.

Best regards!

Hello,

Please edit the second code to this:

li .current-menu-item a {
    background-color: #3f77c7 !important;
    color: white !important;
}

Edit css attributes to your wish.

Best regards!

Hello,

Please edit the code to this:

aside .current_page_item a { color: #3f77c7  !important;}
aside .current_page_item ul li a { color: #565555 !important; }

Result screenshot.

Best regards!