function Scrollbar(){
new SmoothScroll(document,65,15) // target | speed | smooth
}
function SmoothScroll(target, speed, smooth) {
if (target == document)
target = (document.documentElement || document.body.parentNode || document.body) // cross browser support for document scrolling
var moving = false
var pos = target.scrollTop
target.addEventListener('mousewheel', scrolled, false)
target.addEventListener('DOMMouseScroll', scrolled, false)
function scrolled(e) {
e.preventDefault(); // disable default scrolling
var delta = e.delta || e.wheelDelta;
if (delta === undefined) {
//we are on firefox
delta = -e.detail;
}
delta = Math.max(-1, Math.min(1, delta)) // cap the delta to [-1,1] for cross browser consistency
pos += -delta * speed
pos = Math.max(0, Math.min(pos, target.scrollHeight - target.clientHeight + 15)) // + value from SMOOTH
if (!moving) update()
}
function update() {
moving = true
var delta = (pos - target.scrollTop) / smooth
target.scrollTop += delta
if (Math.abs(delta) > 0)
requestFrame(update)
else
moving = false
}
var requestFrame = function() { // requestAnimationFrame cross browser
return (
window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function(func) {
window.setTimeout(func, 1000 / 50);
}
);
}()
}
p {
font-size: 20px;
margin-bottom: 0px;
}
<body onload="Scrollbar()">
<p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
<p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
<p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
</body>