Some underlying elements visible in jQuery hover menu

I have created a hover quick menu that slides down when moving over the homepage link in List Views in my SharePoint Hosted App. Works fine, however some elements from the background are still visible through the menu, please refer below example (highlighted some with red circles):

My javascript includes the following:

$("div.KeuzeMenuHTML").css("opacity", "1.0");
$("div.KeuzeMenuHTML").css("background-color", "#dad4de");
$("div.KeuzeMenuHTML").css("position", "absolute");

How can I prevent this from happening? All help will be appreciated!!!