.fa.fa-minus{
display: none;
}
.fa.fa-plus{
display: block;
}
.dropdown .open .fa.fa-minus {
display: block;
}
.dropdown .open .fa.fa-minus {
display: none;
}
.dropdown .open .fa.fa-minus
.dropdown.open .fa.fa-minus {
display: none;
}
dropdown.open + .fa.fa-plus {}