JS: Scroll between section smooth scrolling anchor js

demo.js

/*-------------------------------------------------*/
/* =  Scroll between sections
/*-------------------------------------------------*/
var $root = $('html, body');

$('a.anchor[href*=#]').on("click",function(event) {
    event.preventDefault();

    var offset = -150;

    $root.animate({
        scrollTop: $( $.attr(this, 'href') ).offset().top + offset
    }, 500);
});