Brayan, the main new study screen dev, has said that it won’t be back. But many have complained about this before you in New study screen [Official thread].
I have provided a CSS solution there. Just add this to the styling section of your note types:
.card {
position: absolute;
width: 90%;
height: 90%;
display: -webkit-box;
-webkit-box-align: stretch;
-webkit-box-pack: center;
-webkit-box-orient: vertical;
}
It should work as long as the card content isn’t longer than the screen.