Add accessibility.

src/scss/components/_character_progression.scss

@@ -11,7 +11,7 @@
             font-family: $font-heading;
             display: block;
             height: 50px;
-            padding: 0px;
+            padding: 0;
             color: $c-light-grey;
             border: none;
             line-height: 50px;

src/scss/global/_accessibility.scss

@@ -0,0 +1,3 @@
+.hidden {
+    display: none;
+}