Improve input contrast

Author: GrantGryczan

frontend/assets/styles/themes.scss

@@ -3,7 +3,7 @@
   --background-color: #0f1a17;
   --text-color: #f0f0f0;
   --warning-text-color: #ff9900;
-  --input-background-color: #00000033;
+  --input-background-color: #00000047;
   // An input's text should never be translucent, because that would make the
   // input appear disabled.
   --input-text-color: #e8e8e8;