Assign min width to the button

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/1886

src/css/support.css

@@ -14,6 +14,9 @@ h3 {
 :root.mobile .supportEntry {
     flex-direction: column;
     }
+.supportEntry > * {
+    min-width: 6em;
+    }
 .supportEntry > div:first-of-type {
     flex-grow: 1;
     }