自學網頁前端

let header = document.querySelector("header");
let headerAnchor = document.querySelectorAll("header nav ul li a")
window.addEventListener("scroll",() => {
if (window.pageYOffset != 0){
header.style.backgroundColor ="rgba(72,60,139,0.3";
header.style.color = "white";
headerAnchor.forEach(a => {
a.style.color = "white";
})
} else{
header.style.backgroundColor = "";
header.style.color = "";
headerAnchor.forEach(a => {
a.style.color = "#381b11";
})
}
})