Use thicker border for button

frontend/src/assets/scss/elementStyles.scss

@@ -58,7 +58,7 @@ b, strong {
 }
 
 .button {
-	border: 1px solid $color__gray--darkest;
+	border: 1.5px solid $color__gray--darkest;
 	display: inline-block;
 	border-radius: 0.25rem;
 	text-align: center;