CSS syntax question for CSS override

Hi Gavick team
I want to change the design slightly bikestore - add different backgrounds for all three styles, but do not know how to formulate them in a CSS override file. I'll write what I want to change and be grateful if you tell me how it is written in CSS override.

1. In the file template.css has the following syntax that prevents styles 1, 2 and 3 to load their background pictures. The syntax is:
html {
background: #767676 url('../images/style1/bg_base.jpg') no-repeat center -500px;
}
If i remove thise, all is ok, interested but is there a smarter way?
Also I want to replace the following colors:
.gkFooter a {
color: #ccc;
}
and
.gkFooter ul.menu li:before {
background: #fabf10;
}

2. File style1.css (identical 2 and 3) I want to replace the following:
html {
background-image: url('../images/style1/bg_base.jpg');
}
with this
html {
background: #90B3E6 url('../images/style1/bg_base.jpg') no-repeat center -500px;
}

3. In file menu.css I want to replace the following (only colors):
.gkMenu > ul > li > a {
color: #6c7072;
text-shadow: 0 1px 0 #eaeaea;
}

Best regards,
Milko Milkov

If you want to change background image for every style you can't make it via override.css. You need to delete the html {background: ....} part from the template.css and make changes for every style in styleX.css files.

For footer please simply paste the code to override.css and change color values (will affect to all styles). In the same way you can change the menu colors but if you want to make them different for every style all code you need paste to styleX.css files not to override.