banner How to replace 7.0 banner image with css gradation

Site URL: https://reformconsulting.com

I'm trying to switch out my bloated jpg banner background for a css gradation—if possible. This is the color I want, but I can't find the correct selector: When I use .desc-wrapper it only extends the width of the type. 

background-image: linear-gradient(#000 0%, #00324f 55%, #003963 100%)

Thanks.

Use this CSS

body.homepage .banner-thumbnail-wrapper.has-description {
    background-image: linear-gradient(#000 0%, #00324f 55%, #003963 100%);
    background-color: transparent !important;
}
body.homepage .banner-thumbnail-wrapper.has-description img {
    visibility: hidden;
}

Thanks, I tried that on a test page. When I deleted the jpg background image to see if the color was there, it wasn't. No color, so no visible text. 

I'm starting to think it might be better to leave it as is or try to switch to svg. My goal was to shorten load time. 

If you remove the image, the page code structure will change so will need a new code