this is a code to detect if the section which I'm scrolling right now is in the viewport or not. This code actually works only if I get onto any section and refresh the page, it doesn't work continuously when I scroll through the page.

var secArr = document.querySelectorAll('section');


secArr.forEach(onscroll = function (element) {
    var bounding = element.getBoundingClientRect();

    if (bounding.top <= 350.00 && bounding.top >= -270.00) {
        if (!element.classList.contains("your-active-class")) {
            element.setAttribute("class", "your-active-class");
        }
    } 
    else {
        element.removeAttribute("class");
    }
});