How to set responsive block height?

Question

css

There is such a design. The height of the first block is set in pixels. Blocks 2 and 3 have position: fixed and anchor to the bottom + and have bottom: 80px padding. How can I set the height of block 2 so that it automatically expands and shrinks depending on how much free space is left between block 1 and block 3 at different screen resolutions?

Answer 1

Use display: flex; in the block to be edited