Space between the screen and the text

[Kawajapa]

Hi guys I have an ask. I am used to google notes, but i did need something like to markor, luckily i find it. But I used to the little space beetween the text and the screen, (that space showed up on books or ebooks) but i could find the way to add that, so i want to know if i could find it or isnt doesnt exist. Thanks. I would like to know too if there is a way to customize the light theme, because that sad grey dont like myself.