logo resize on scroll for Unite theme just like on Colorlib website

how to get logo resize like your support site https://colorlibsupport.com/c/unite-support/

We are using a custom built theme for our website and it features completely different header structure from one you can see on Unite theme. Therefore it would require way too much work to modify Unite theme. It is possible for it is way out of scope of free support.

If you are not a developer yourself you can always hire someone on Freelancer.com Upwork (former oDesk) or other websites.

thanks for suggestions