Change image of ion-tab when it is selected


#1

I want to change image of selected tab using css but i cannot how to change in ion-tab so need help.

My tab is like below image

I am using below css for display image in ion-tab

.ion-md-challenges
{
background-repeat: no-repeat;
background-position:50%;
height: 30px;
width: 30px;
background-image: url(’./…/assets/images/icon/challenge.png’);
background-size:cover;
}

Thanks