Can't Change Header Image (Hybrid News Theme) or even fonts

Hey everyone,

In short, I just implemented the theme: “Hybrid News” (child of “Hybrid”).

I’ve tried to edit the style.css to change the header, but to no avail.

Here’s the part of code I’m trying to alter:

/**
* Header
************************************************/
#header-container {
overflow: hidden;
height: 90px;
background: url(images/bg-header.png) repeat-x 0 0;
border-bottom: 1px solid #021f32;
}

I’ve tried changing the bolded line to background: url(images/blue-banner.jpg) no repeat; but haven’t had any luck. Actually, I tried changing any part of the style.css (ie: fonts) and nothing is happening.

My website: https://www.fbsserver.org

Maybe this is because the skin is a child skin? I’m not sure. Can anyone help me with this?

Thank you in advance.