.fi{background-size:contain;background-position:50%;background-repeat:no-repeat;display:inline-block;vertical-align:middle}
.fi-pl{background-image:url('/static/img/flags/pl.svg')}
.fi-gb{background-image:url('/static/img/flags/gb.svg')}
.fi-de{background-image:url('/static/img/flags/de.svg')}
.fi-fr{background-image:url('/static/img/flags/fr.svg')}