Applied grayscale, brightness, contrast filters and opacity to stopped images (#246)

When the image is black and white, there is no visual difference between
when the image is running and when it is not.

---------

Co-authored-by: Ricardo Pinto <[email protected]>

Author: tempius

src/assets/scss/common/_card.scss

@@ -40,7 +40,8 @@
 		position: relative;
 
 		&.stop img {
-			filter: grayscale(100%);
+			filter: grayscale(100%) brightness(50%) contrast(120%);
+			opacity: 0.5;
 		}
 
 		img {
@@ -56,7 +57,8 @@
 		justify-content: center;
 
 		&.stop img {
-			filter: grayscale(100%);
+			filter: grayscale(100%) brightness(50%) contrast(120%);
+			opacity: 0.5;
 		}
 
 		img {