[Strange] Ionic emulate looks different everytime

so…

since the ion-segment element was overlaping ion-button on the toolbar, I used some css override to make it look different on IOS.

It looks good on browser(iOS responsive mode), but when i run ionic emulate ios, the width of the segment went 100% again overlaping the ion-button…

so in the app.core.scss i add
$segment-button-ios-toolbar-button-max-width: 60px;

sometimes this works sometimes dont… even if i change nth at all, running the ionic build ios hv different results each time… why?