set card background grey

src/app/shared/components/card/card.component.scss

@@ -3,6 +3,7 @@
   box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
   transition: 0.3s;
   height: 100%;
+  background-color: rgba(170, 170, 170, 0.8);
 
   &:hover {
     box-shadow: 0 8px 16px 0 rgba(0, 0, 0, 0.2);