Expanding a block to the empty space of the parent element (div expand)

Today I came across an unpleasant problem - when using block layout, I needed to stretch a block to fill the empty space of the parent element vertically (div expand). Naturally, there is no difficulty in doing this horizontally - simply set the display to block and it will work =).

Form without tables

To create a form using tables, even a beginner webmaster can do it, but for formatting a tableless form, some skills are required. Let's consider a simple example, such as a login form.