Modern Business: Add a utility css class for spacer block

modern-business/sass/blocks/_blocks.scss

@@ -805,6 +805,17 @@
 		}
 	}
 
+	//! Spacer
+	.wp-block-spacer {
+		&.desktop-only {
+			display: none;
+
+			@include media(tablet) {
+				display: block;
+			}
+		}
+	}
+
 	//! Twitter Embed
 	.wp-block-embed-twitter {
 		word-break: break-word;

modern-business/style-rtl.css

@@ -4255,6 +4255,16 @@ body.page .main-navigation {
   display: none;
 }
 
+.entry .entry-content .wp-block-spacer.desktop-only {
+  display: none;
+}
+
+@media only screen and (min-width: 768px) {
+  .entry .entry-content .wp-block-spacer.desktop-only {
+    display: block;
+  }
+}
+
 .entry .entry-content .wp-block-embed-twitter {
   word-break: break-word;
 }

modern-business/style.css

@@ -4267,6 +4267,16 @@ body.page .main-navigation {
   display: none;
 }
 
+.entry .entry-content .wp-block-spacer.desktop-only {
+  display: none;
+}
+
+@media only screen and (min-width: 768px) {
+  .entry .entry-content .wp-block-spacer.desktop-only {
+    display: block;
+  }
+}
+
 .entry .entry-content .wp-block-embed-twitter {
   word-break: break-word;
 }