[a11y] Small fixes and improvements

src/pretix/static/pretixpresale/scss/main.scss

@@ -60,6 +60,8 @@ footer nav ul {
     display: flex;
     justify-content: center;
     list-style: none;
+    padding: 0;
+    flex-wrap: wrap;
 }
 footer nav li:not(:first-child):before {
     content: "·";