How to define the width or height of an element in css?

Question

css

Hello! How to get the width of an element in css.
For example, I need to calculate the margin from the top: .element{margin-top: calc(50vh-n)}
where n is the height of the element. How is it labeled

Answer 1

vh-vw are just units.

.element{
margin-top: calc(50vh-n) // n - тут не прокатит, это переменная, её нельзя пропихнуть в css
}

this is css, you can’t really code in it, there are no variables here if you don’t use preprocessors.
you need to use js, and directly js to work with sizes.
using jquery library like
var h = $('#container').css('height');