Modify layout for mobile, hide unknown prices

translations/en.json

@@ -30,6 +30,7 @@
       "earlyVisitor": "Early visitor ticket (until XX.XX)",
       "supporter": "Supporter ticket (TipiLAN T-shirt)",
       "cta": "Buy an early ticket from Fienta!",
+      "tba": "We will announce prices and sale dates soon!",
       "buyButton": "Buy tickets here"
     },
     "sponsors": {