Fix post mention preview behaviour on mobile
Fix post mention preview behaviour on mobile

flarum/mentions,amdad/mentions,amdad/mentions,flarum/flarum-ext-mentions,sijad/flarum-ext-mentions,flarum/flarum-ext-mentions,sijad/flarum-ext-mentions,flarum/flarum-ext-mentions,flarum/mentions,sijad/flarum-ext-mentions