Change size of stacked ion-input label

Ionic Framework
1

I have a stacked ion-input like this:

                <ion-item>
                    <ion-input label="Tu usuario o email" labelPlacement="stacked">
                   </ion-input>
                </ion-item>

I want to increase the font-size of the label but can’t find a way to target it with CSS. I tried with .label-text class but it didn’t work.