Reduce padding-right, but only for input[type=number]

src/pretix/static/pretixbase/scss/_theme.scss

@@ -1,3 +1,7 @@
+input[type=number] {
+  padding-right: 0; // Setting the padding-right to zero, as some versions Firefox render the arrow-buttons on number inputs useless.
+}
+
 .sidebar-nav li > a > .fa {
   color: $navbar-inverse-bg;
 }

src/pretix/static/pretixpresale/scss/widget.scss

@@ -83,6 +83,9 @@
       @include box-shadow(inset 0 1px 1px rgba(0, 0, 0, .075), 0 0 8px $color-rgba);
     }
   }
+  input[type=number] {
+    padding-right: 0; // Setting the padding-right to zero, as some versions Firefox render the arrow-buttons on number inputs useless.
+  }
   input[type="checkbox"],
   input[type="radio"] {
     box-sizing: border-box; // 1