Fill the rest of the page by height

Hi pals,
I am have a<ion-textarea style="height: 200px;"></ion-textarea> and

  1. as for ‘block’ which fills the screen to its width, I want my ion-textarea’s height to fill the rest of the page screen to the bottom.
  2. Also, I want its height not to be changed further. Could you please help?

Thanks in advance!