Changes to style.css not working

Hi All,

I am having issues with my site. The parent theme is Hoffman and I have created a child theme for all the changes that I wanted.

The exact part I am having issues with is this below:

.post-header:after {
content: “”;
display: block;
width: 96px;
height: 4px;
background: #202020;
margin: 40px auto;
}

Now I want to make this block the same color as my background so that I still have the padding there, but it is not visible. No matter what I try, the changes are not visible on my site.

I have tried adding the code above to my child theme, the parent theme and even the “Custom CSS” section in WordPress but none of these have any effect. I even just tried adding this code below to the child theme and Custom CSS but no luck.

.post-header:after {
background: 202020;
}

When using inspect element in Google Chrome, the corresponding code shows up in the (index):13 section but I have no idea how to find or edit this file. If I change the color in inspect element the changes show which is strange since it does not work when done through my Child theme/Custom CSS.

Does anyone have any idea what could be the solution to this problem?

The page I need help with: [log in to see the link]