script.js

if(viewportwidth > 1183 && !$('.page').hasClass('home') ){
			$('a.icon--search').on('click touchend',function(e) {
				e.preventDefault();
				$(this).toggleClass('nav-active');
				$(this).next('.search__form').toggleClass('search__form--active');
				$('.header__secondary-menu').fadeToggle();
			});
			$('.search__form').css('top','5.45em');
		} else {
			$('a.icon--search').on('click touchend',function(e) {
			    e.preventDefault();
			    $(this).toggleClass('nav-active');
			    $(this).next('.search__form').toggleClass('search__form--active');
			    $('.header__nav_icon').removeClass('nav-active');
			});
		}

style.css

.search__form.search__form--active {
	/* .is-vishidden makes this position:absolute */
	@include triple-transition(max-height, 0.6s, padding-top, 0.3s, padding-bottom, 0.3s, ease-in-out);
	display:block;
	left: 0em;
	top: 3.4em;
	overflow: hidden;
	text-align:left;
	width: 100%;
	height: auto;
	max-height:8em;
	padding: 0em $pad-and-quarter $pad-and-quarter;
	border: 0;
	clip: auto;
	@media all and (min-width: $bp-small-5) {
		top: 4.9em;
	}
	@media all and (min-width: $bp-xl) {
		top: 9.75em;
	}

}
@at-root {
	//This is an adaptation for the homepage
	.home .header__icon-wrap .search .search__form.search__form--active {
		@media all and (min-width: $bp-xl) {
			top: 5.45em;
			height: auto;
			max-height:8em;
		}
	}
	.no-js .home .header__icon-wrap .search a:focus + .search__form, .no-js .home .header__icon-wrap .search .search__form:hover {
		@media all and (min-width: $bp-xl) {
			top: 5.45em;
			height: auto;
			max-height:8em;
		}
	}
}