ISTWCMS-5876: removed the css that assigned a background color for the...

ISTWCMS-5876: removed the css that assigned a background color for the fallback image in banner as well as the banner media container. keeping the darkened effect by removing the opacity and background color and using filter css

src/patterns/04-components/card/card--banner/_card--banner.scss

@@ -226,7 +226,6 @@
 }
 
 .card__banner--image {
-  background: var(--uw-black);
   margin-bottom: 0;
   padding: 0;
   position: relative;
@@ -281,29 +280,29 @@
     margin: 0;
   }
   a {
-    background: var(--uw-black);
+
     .card__banner--media {
       margin-bottom: 0;
-      opacity: 1;
       order: inherit;
       transition-delay: 0s;
       transition-duration: 0.2s;
-      transition-property: color, background-color, border-color, opacity;
+      transition-property: color, border-color, filter;
       transition-timing-function: linear;
     }
 
     &:hover {
+
       .card__banner--media {
-        opacity: 0.6;
+        filter: brightness(50%);
         transition-delay: 0s;
         transition-duration: 0.2s;
-        transition-property: color, background-color, border-color, opacity;
+        transition-property: color, border-color, filter;
         transition-timing-function: linear;
       }
     }
   }
   .uw-picture__fallback{
-    background: var(--uw-black);
+    //background: var(--uw-black);
     display: block;
   }
 }