Apply $tabs-md-tab-font-size-active to one tab only

I am trying to reduce the font size, but only if you click on one specifc tab, not all of them. I tried doing this in my tabs.html and tabs.scss but it doesn’t seem to work.
This is my tabs.html

<ion-tabs tabsPlacement="bottom">
 //some tab
  <ion-tab class="font-size" [root]="tab2" tabTitle="Meine Gruppe" tabIcon="ios-people-outline"></ion-tab>
//some more tabs

And this is my tabs.scss:

page-tabs {
    .font-size {
        $tabs-md-tab-font-size-active: 1.2rem;

I am grateful for any help!

Hi, does nobody know how to do this?