Dispatch-Demo Custom Grid Background

Hi,

I want to set a semi-transparent-background behind the header of my main grid. It works if I write my code in this CSS-line:

.wpsp-card .wpsp-content-wrap

But it affects also the other images on front page which use "contains wpsp-card". So I added new CSS and it seems to work:

.wpsp-grid .wpsp-content-wrap{   
    background-color: rgba(0, 0, 0, 0.35)!important;
    background: -webkit-gradient(linear, left bottom, left top, color-stop(30%, rgba(80, 50, 50, 0.5)), to(rgba(0, 0, 0, 0.3)))!important;	
	background: linear-gradient(0deg, rgba(0, 0, 0, 0.2) 30%, rgba(0, 0, 0, 0.5) 100%)!important;
}

It works but is this correct?