Change text block color opacity without changing the opacity of the text.

Hi there!

I have been trying to change the text block color background transparency. I was able to do so but as soon as I change the transparency the text fades away as well. 

Here is the custom css i used:

 #block-yui_3_17_2_1_1615337069337_4766
{background: #36373C ; opacity: 0.6; 
  padding: 20px 50px; text-opacity: .0 }

How can I change a text block color opacity without changing the opacity of the text?

Thank you!!

What's your URL? 

https://rectangle-calliope-zppr.squarespace.com/members-login

The site is not published yet. let me know if you can access it 🙂

I figured it had with someone's previous answer 

Here was the solution:

#block-d325a806d44c4257f1d4 {
background: #000000;
opacity: 0.5;
padding: 5px;
text-align: center;
}