CSS custom properties
Font size
The widget inheritsfont-size from its placement context. Text scales with the surrounding page rather than using a fixed size. There is no --resurs-checkout-* property for size; control it with the native CSS font-size property on the component.
font-size on the group to match your own subtitle (the component can’t read it; it’s a sibling in your DOM).
Animation
The widget animates its expand and collapse using a CSS Grid row height transition. If your checkout already animates other payment methods, you can match the timing so all cards feel consistent.--resurs-checkout-transition-duration: 0s to disable animation entirely.