document.querySelector('.header__arrow').addEventListener('click', arrowScroll);
function arrowScroll(){
	let header = document.querySelector('.header').offsetHeight;
	let currentScroll = window.pageYOffset;
	let sumScroll = header - currentScroll;
	window.scrollBy(0,sumScroll);
}

document.querySelector(".header__arrow").addEventListener('click', arrowScroll);
function arrowScroll(){
    document.querySelector(".header").scrollIntoView({ behavior: 'smooth' });
}