reintroduce outline

public/styles/style.css

@@ -294,13 +294,10 @@ footer {
   margin: 0;
   padding: 0.4em 0.6em;
 }
-#accessibility-options button:hover {
+#accessibility-options button:hover, #accessibility-options button:focus {
   background-color: #5b00d2;
   cursor: pointer;
 }
-#accessibility-options button:focus {
-  outline: none;
-}
 
 #font-selection {
   color: #333333;

public/styles/style.scss

@@ -129,13 +129,10 @@ footer {
     margin: 0;
     padding: 0.4em 0.6em;
   }
-  button:hover {
+  button:hover, button:focus {
     background-color: $menu_hover_light;
     cursor: pointer;
   }
-  button:focus {
-    outline: none;
-  }
 }
 #font-selection {
   color: $color_light;