How can I make my dark blue dropdown background non-transparent - html

Question

I have attached an image showing my dropdown. The issue is that you can still see the text behind the dropdown. I want it to be deep blue so the text behind it can be hidden. How can I change this with CSS so that the background won't let me see the text behind it ?
As you can see on the image, ns can be seen through that dropdown. And last 12 months is kind of overlapped.
here is the CSS code of the tabs
.menu_button {
width: 19%;
height: 30px;
background: #1A3F73;
float: left;
margin-right: 5px;
margin-bottom: 10px;
text-align: center;
border: 1px solid black;
border-radius: 5px;
color: #f4f442;
font-weight: bold;
font-size: 13px;
}
.menu_button ul {
margin-top: 10px;
background: #1A3F73;
list-style-type: none;
width: 100%;
display: none;
margin-left: 0px;
background: rgba(128,128,128,0.7);
}
.menu_button li {
height: 30px;
background: #1A3F73;
margin: 0px;
width: 100%;
opacity: 1;
}
HTML
<a style='color:#f4f442;' href ='course/view.php?id=11'><div class ='menu_button'><span class='middle daily'>Daily Magic Spells</span><br /><div class='dd'><ul><li class='recent'><a style='color:#f4f442' href='recent.php'>Most recent leaders</a></li><li class='threem'><a style='color:#f4f442' href='three-month.php'>last 3 months</a></li><li class='sixm'><a style='color:#f4f442' href='six-month.php'>last 6 months</a></li><li class='twelvem'><a style='color:#f4f442' href='year.php'>last 12 months</a></li></ul></div></div></a>

Answer 1

You need to remove the opacity from your rgba background color
.test{
height: 100px;
width: 100px;
background-color: rgba(26,63,115, .5)
}
If you change the
background-color: rgba(26,63,115, .5)
to
background-color: rgba(26,63,115, 1)
It will remove the Opacity making the color solid
With your code change
.menu_button ul {
margin-top: 10px;
background: #1A3F73;
list-style-type: none;
width: 100%;
display: none;
margin-left: 0px;
background: rgba(128,128,128,0.7);
}
to
.menu_button ul {
margin-top: 10px;
background: #1A3F73;
list-style-type: none;
width: 100%;
display: none;
margin-left: 0px;
background: rgba(128,128,128,1);
}