magic-scroll.js

//scroll anchor links fixed
var switchView = function (hash = location.hash, adjust = 5) {
	
    /* change adjust value if necessary*/

/* Remember to import https://unpkg.com/smoothscroll-polyfill/dist/smoothscroll.min.js for cross-browser support*/

//get top position relative to viewport
    try {
        var elem = document.querySelector(hash);
        var elemRect = elem.getBoundingClientRect(),
            bodyRect = document.body.getBoundingClientRect(),
            offset = elemRect.top - bodyRect.top;
        window.scroll({
            top: offset - adjust,
            behavior: 'smooth'
        })
    } catch (DOMException) {
        location.hash = "";
    } 
}

document.addEventListener('DOMContentLoaded', () => { switchView() });
window.onhashchange = () => { switchView() }

document.querySelectorAll('a[href^="#"]').forEach(anchor => {

anchor.onclick = (e) => {

    //be sure the target is right
    //prevent <button> inside <a> case 
    var target = e.target;
    while ( target.nodeName.toLowerCase() != "a" ) {
        target = target.parentNode
    }
    
    e.preventDefault()
    switchView(target.attributes.href.value)

//auto close navbar
$('.navbar-collapse').collapse('hide')
    
}
})