There is a ->width() option for cards. How can the height be defined?
Although Nova does not provide a ->height() method, when you generate a Nova card it creates resources/js/components/Card.vue automatically (see Nova card documentation)
The Card.vue file allows you to modify the Vue template for the card element. Since Nova uses the Tailwind CSS framework, you should be able to use the Height classes of Tailwind CSS inside Card.vue.