#phone_btn {
    display: none;
    width: 42px;
    flex: 0 0 42px;
    height: 42px;
    margin: 0 10px;
    background: #fff;
    border-radius: 50%;
    text-align: center;
    border: 2px solid #333333;
    line-height: normal;
    align-items: center;
    justify-content: center;
}
#phone_btn i {
    font-size: 24px;
    color: #353535 !important;
    line-height: inherit;	
}
@media (max-width: 991px) {
	#phone_btn {
		display: flex;
	}
}