Change Opacity of Background for Text Block - Fluid

Site URL: https://www.theessenceofyou.ca

Hello!

In 7.1 I had the code nailed down and now I feel like i'm starting over with my knowledge. I'm looking to change the opacity of the text box when the background is enabled. I'd like the background to be at 70% opacity, with the text not being affected by the opacity. Thanks! 

Cheryl

Add to Design > Custom CSS

div#block-21185f8f7362627a223c {
    background-color: rgba(89, 90, 92,0.7);
}