navigation bar behavior based on scroll bar
此腳本不應該直接安裝，它是一個供其他腳本使用的函式庫。欲使用本函式庫，請在腳本 metadata 寫上： // @require https://update.greasyfork.org/scripts/491240/1352705/scroll2078.js
document.addEventListener('DOMContentLoaded', function () {
const header = document.querySelector('.header');
let lastScrollTop = 0;
function handleScroll() {
let scrollTop = window.pageYOffset || document.documentElement.scrollTop;
if (scrollTop > lastScrollTop) {
header.style.transform = 'translateY(-52px)';
} else {
if (scrollTop <= 18) {
header.style.transform = `translateY(${scrollTop - 18}px)`;
} else {
header.style.transform = 'translateY(0px)';
}
}
lastScrollTop = scrollTop <= 0 ? 0 : scrollTop;
}
window.addEventListener('scroll', handleScroll);
header.style.transform = 'translateY(-16px)';
});