Revert "Revert "Fix/325 responsive breadcrumb (#437)" (#438)"

This reverts commit ae99783.

mu-plugins/blocks/site-breadcrumbs/postcss/style.pcss

@@ -1,32 +1,32 @@
 .wp-block-wporg-site-breadcrumbs {
-	display: flex;
-	align-items: center;
-
 	& a {
-		color: var(--wp--preset--color--charcoal-1);
+		color: var(--wp--preset--color--charcoal-4);
 		text-decoration-line: none;
 
 		&:hover {
 			text-decoration-line: underline;
 		}
 	}
 
-	& > span:not(:first-child) {
+	& > span {
+		display: inline-block;
 
-		/* This ensures that the square separator is reliably centered. */
-		display: flex;
-		align-items: center;
-		margin-top: 0;
+		&:not(:last-child) {
 
-		&::before {
-			content: "/";
-			display: inline-block;
-			font-weight: 400;
-			margin: 0 0.5rem;
+			/* This ensures that the square separator is reliably centered. */
+			margin-top: 0;
+
+			&::after {
+				content: "/";
+				display: inline-block;
+				font-weight: 400;
+				margin: 0 var(--wp--preset--spacing--10);
+				color: var(--wp--preset--color--light-grey-1);
+			}
 		}
 	}
 
 	& .is-current-page {
-		font-weight: 700;
+		color: var(--wp--preset--color--charcoal-1);
 	}
 }