Add button--disabled class

src/assets/scss/elementStyles.scss

@@ -78,6 +78,23 @@ b, strong {
 		}
 	}
 
+	@at-root #{&}--disabled {
+		position: relative;
+		pointer-events: none;
+
+		@include user-select(none);
+
+		&::after {
+			content: '';
+			width: 100%;
+			height: 100%;
+			position: absolute;
+			left: 0;
+			top: 0;
+			background-color: rgba(240, 240, 240, 0.4);
+		}
+	}
+
 	@at-root #{&}--orange {
 		border-color: $color__orange--primary;
 		&:hover { border-color: $color__orange--darker; }