Soft scroll bar

$(function(){
    $.stellar();
});


/*! Stellar.js v0.4.0 | Copyright 2012, Mark Dalgleish | http://markdalgleish.com/projects/stellar.js | http://markdalgleish.mit-license.org */
(function(e,t,n,r){function d(t,n){this.element=t,this.options=e.extend({},s,n),this._defaults=s,this._name=i,this.init()}var i="stellar",s={scrollProperty:"scroll",positionProperty:"position",horizontalScrolling:!0,verticalScrolling:!0,horizontalOffset:0,verticalOffset:0,parallaxBackgrounds:!0,parallaxElements:!0,hideDistantElements:!0,viewportDetectionInterval:1e4,hideElement:function(e){e.hide()},showElement:function(e){e.show()}},o={scroll:{getTop:function(e){return e.scrollTop()},setTop:function(e,t){e.scrollTop(t)},getLeft:function(e){return e.scrollLeft()},setLeft:function(e,t){e.scrollLeft(t)}},position:{getTop:function(e){return parseInt(e.css("top"),10)*-1},setTop:function(e,t){e.css("top",t)},getLeft:function(e){return parseInt(e.css("left"),10)*-1},setLeft:function(e,t){e.css("left",t)}},margin:{getTop:function(e){return parseInt(e.css("margin-top"),10)*-1},setTop:function(e,t){e.css("margin-top",t)},getLeft:function(e){return parseInt(e.css("margin-left"),10)*-1},setLeft:function(e,t){e.css("margin-left",t)}},transform:{getTop:function(e){return e.css(a+"transform")!=="none"?parseInt(e.css(a+"transform").match(/(-?[0-9]+)/g)[5],10)*-1:0},setTop:function(e,t){h(e,t,"Y")},getLeft:function(e){return e.css(a+"transform")!=="none"?parseInt(e.css(a+"transform").match(/(-?[0-9]+)/g)[4],10)*-1:0},setLeft:function(e,t){h(e,t,"X")}}},u={position:{setTop:function(e,t){e.css("top",t)},setLeft:function(e,t){e.css("left",t)}},transform:{setTop:function(e,t,n){h(e,t-n,"Y")},setLeft:function(e,t,n){h(e,t-n,"X")}}},a=function(){var t="";return e.browser.webkit?t="-webkit-":e.browser.mozilla?t="-moz-":e.browser.opera?t="-o-":e.browser.msie&&(t="-ms-"),t}(),f=n.createElement("div").style.backgroundPositionX!==r,l=function(){return f?function(e,t,n){e.css({"background-position-x":t,"background-position-y":n})}:function(e,t,n){e.css("background-position",t+" "+n)}}(),c=function(){return f?function(e){return[e[0].style.backgroundPositionX,e[0].style.backgroundPositionY]}:function(e){return e.css("background-position").split(" ")}}(),h=function(e,t,n){var r=e.css(a+"transform");r==="none"?e.css(a+"transform","translate"+n+"("+t+"px)"):e.css(a+"transform",p(r,/(-?[0-9]+[.]?[0-9]*)/g,n==="X"?5:6,t))},p=function(e,t,n,i){var s,o,u;return e.search(t)===-1?e:(s=e.split(t),u=n*2-1,s[u]===r?e:(s[u]=i,s.join("")))};d.prototype={init:function(){this.options.name=i+"_"+Math.floor(Math.random()*1e4),this._defineElements(),this._defineGetters(),this._defineSetters(),this.refresh(),this._startViewportDetectionLoop(),this._startAnimationLoop()},_defineElements:function(){this.element===n.body&&(this.element=t),this.$scrollElement=e(this.element),this.$element=this.element===t?e("body"):this.$scrollElement,this.$viewportElement=this.options.viewportElement!==r?e(this.options.viewportElement):this.$scrollElement[0]===t||this.options.scrollProperty.indexOf("scroll")===0?this.$scrollElement:this.$scrollElement.parent()},_defineGetters:function(){var e=this;this._getScrollLeft=function(){return o[e.options.scrollProperty].getLeft(e.$scrollElement)},this._getScrollTop=function(){return o[e.options.scrollProperty].getTop(e.$scrollElement)}},_defineSetters:function(){var e=this;this._setScrollLeft=function(t){o[e.options.scrollProperty].setLeft(e.$scrollElement,t)},this._setScrollTop=function(t){o[e.options.scrollProperty].setTop(e.$scrollElement,t)},this._setLeft=function(t,n,r){u[e.options.positionProperty].setLeft(t,n,r)},this._setTop=function(t,n,r){u[e.options.positionProperty].setTop(t,n,r)}},refresh:function(){var n=this,r=n._getScrollLeft(),i=n._getScrollTop();this._setScrollLeft(0),this._setScrollTop(0),this._setOffsets(),this._findParticles(),this._findBackgrounds(),navigator.userAgent.indexOf("WebKit")>0&&e(t).load(function(){var e=n._getScrollLeft(),t=n._getScrollTop();n._setScrollLeft(e+1),n._setScrollTop(t+1),n._setScrollLeft(e),n._setScrollTop(t)}),n._setScrollLeft(r),n._setScrollTop(i)},_findParticles:function(){var t=this,n=this._getScrollLeft(),i=this._getScrollTop();if(this.particles!==r)for(var s=this.particles.length-1;s>=0;s--)this.particles[s].$element.data("stellar-elementIsActive",r);this.particles=[];if(!this.options.parallaxElements)return;this.$element.find("[data-stellar-ratio]").each(function(n){var i=e(this),s,o,u,a,f,l,c,h,p,d=0,v=0,m=0,g=0;if(!i.data("stellar-elementIsActive"))i.data("stellar-elementIsActive",this);else if(i.data("stellar-elementIsActive")!==this)return;t.options.showElement(i),i.data("stellar-startingLeft")?(i.css("left",i.data("stellar-startingLeft")),i.css("top",i.data("stellar-startingTop"))):(i.data("stellar-startingLeft",i.css("left")),i.data("stellar-startingTop",i.css("top"))),u=i.position().left,a=i.position().top,f=i.css("margin-left")==="auto"?0:parseInt(i.css("margin-left"),10),l=i.css("margin-top")==="auto"?0:parseInt(i.css("margin-top"),10),h=i.offset().left-f,p=i.offset().top-l,i.parents().each(function(){var t=e(this);if(t.data("stellar-offset-parent")===!0)return d=m,v=g,c=t,!1;m+=t.position().left,g+=t.position().top}),s=i.data("stellar-horizontal-offset")!==r?i.data("stellar-horizontal-offset"):c!==r&&c.data("stellar-horizontal-offset")!==r?c.data("stellar-horizontal-offset"):t.horizontalOffset,o=i.data("stellar-vertical-offset")!==r?i.data("stellar-vertical-offset"):c!==r&&c.data("stellar-vertical-offset")!==r?c.data("stellar-vertical-offset"):t.verticalOffset,t.particles.push({$element:i,$offsetParent:c,isFixed:i.css("position")==="fixed",horizontalOffset:s,verticalOffset:o,startingPositionLeft:u,startingPositionTop:a,startingOffsetLeft:h,startingOffsetTop:p,parentOffsetLeft:d,parentOffsetTop:v,stellarRatio:i.data("stellar-ratio")!==r?i.data("stellar-ratio"):1,width:i.outerWidth(!0),height:i.outerHeight(!0),isHidden:!1})})},_findBackgrounds:function(){var t=this,n=this._getScrollLeft(),i=this._getScrollTop(),s;this.backgrounds=[];if(!this.options.parallaxBackgrounds)return;s=this.$element.find("[data-stellar-background-ratio]"),this.$element.is("[data-stellar-background-ratio]")&&s.add(this.$element),s.each(function(){var s=e(this),o=c(s),u,a,f,h,p,d,v,m,g,y=0,b=0,w=0,E=0;if(!s.data("stellar-backgroundIsActive"))s.data("stellar-backgroundIsActive",this);else if(s.data("stellar-backgroundIsActive")!==this)return;s.data("stellar-backgroundStartingLeft")?l(s,s.data("stellar-backgroundStartingLeft"),s.data("stellar-backgroundStartingTop")):(s.data("stellar-backgroundStartingLeft",o[0]),s.data("stellar-backgroundStartingTop",o[1])),p=s.css("margin-left")==="auto"?0:parseInt(s.css("margin-left"),10),d=s.css("margin-top")==="auto"?0:parseInt(s.css("margin-top"),10),v=s.offset().left-p-n,m=s.offset().top-d-i,s.parents().each(function(){var t=e(this);if(t.data("stellar-offset-parent")===!0)return y=w,b=E,g=t,!1;w+=t.position().left,E+=t.position().top}),u=s.data("stellar-horizontal-offset")!==r?s.data("stellar-horizontal-offset"):g!==r&&g.data("stellar-horizontal-offset")!==r?g.data("stellar-horizontal-offset"):t.horizontalOffset,a=s.data("stellar-vertical-offset")!==r?s.data("stellar-vertical-offset"):g!==r&&g.data("stellar-vertical-offset")!==r?g.data("stellar-vertical-offset"):t.verticalOffset,t.backgrounds.push({$element:s,$offsetParent:g,isFixed:s.css("background-attachment")==="fixed",horizontalOffset:u,verticalOffset:a,startingValueLeft:o[0],startingValueTop:o[1],startingBackgroundPositionLeft:isNaN(parseInt(o[0],10))?0:parseInt(o[0],10),startingBackgroundPositionTop:isNaN(parseInt(o[1],10))?0:parseInt(o[1],10),startingPositionLeft:s.position().left,startingPositionTop:s.position().top,startingOffsetLeft:v,startingOffsetTop:m,parentOffsetLeft:y,parentOffsetTop:b,stellarRatio:s.data("stellar-background-ratio")===r?1:s.data("stellar-background-ratio")})})},destroy:function(){var t,n,r,i,s;for(s=this.particles.length-1;s>=0;s--)t=this.particles[s],n=t.$element.data("stellar-startingLeft"),r=t.$element.data("stellar-startingTop"),this._setLeft(t.$element,n,n),this._setTop(t.$element,r,r),this.options.showElement(t.$element),t.$element.data("stellar-startingLeft",null).data("stellar-elementIsActive",null).data("stellar-backgroundIsActive",null);for(s=this.backgrounds.length-1;s>=0;s--)i=this.backgrounds[s],l(i.$element,i.startingValueLeft,i.startingValueTop);this._animationLoop=e.noop,clearInterval(this._viewportDetectionInterval)},_setOffsets:function(){var n=this;e(t).unbind("resize.horizontal-"+this.name).unbind("resize.vertical-"+this.name),typeof this.options.horizontalOffset=="function"?(this.horizontalOffset=this.options.horizontalOffset(),e(t).bind("resize.horizontal-"+this.name,function(){n.horizontalOffset=n.options.horizontalOffset()})):this.horizontalOffset=this.options.horizontalOffset,typeof this.options.verticalOffset=="function"?(this.verticalOffset=this.options.verticalOffset(),e(t).bind("resize.vertical-"+this.name,function(){n.verticalOffset=n.options.verticalOffset()})):this.verticalOffset=this.options.verticalOffset},_repositionElements:function(){var e=this._getScrollLeft(),t=this._getScrollTop(),n,r,i,s,o,u,a,f=!0,c=!0,h,p,d,v,m;if(this.currentScrollLeft===e&&this.currentScrollTop===t&&this.currentWidth===this.viewportWidth&&this.currentHeight===this.viewportHeight)return;this.currentScrollLeft=e,this.currentScrollTop=t,this.currentWidth=this.viewportWidth,this.currentHeight=this.viewportHeight;for(m=this.particles.length-1;m>=0;m--)i=this.particles[m],s=i.isFixed?1:0,this.options.horizontalScrolling&&(h=(e+i.horizontalOffset+this.viewportOffsetLeft+i.startingPositionLeft-i.startingOffsetLeft+i.parentOffsetLeft)*-(i.stellarRatio+s-1)+i.startingPositionLeft,d=h-i.startingPositionLeft+i.startingOffsetLeft),this.options.verticalScrolling&&(p=(t+i.verticalOffset+this.viewportOffsetTop+i.startingPositionTop-i.startingOffsetTop+i.parentOffsetTop)*-(i.stellarRatio+s-1)+i.startingPositionTop,v=p-i.startingPositionTop+i.startingOffsetTop),this.options.hideDistantElements&&(c=!this.options.horizontalScrolling||d+i.width>(i.isFixed?0:e)&&d<(i.isFixed?0:e)+this.viewportWidth+this.viewportOffsetLeft,f=!this.options.verticalScrolling||v+i.height>(i.isFixed?0:t)&&v<(i.isFixed?0:t)+this.viewportHeight+this.viewportOffsetTop),c&&f?(i.isHidden&&(this.options.showElement(i.$element),i.isHidden=!1),this.options.horizontalScrolling&&this._setLeft(i.$element,h,i.startingPositionLeft),this.options.verticalScrolling&&this._setTop(i.$element,p,i.startingPositionTop)):i.isHidden||(this.options.hideElement(i.$element),i.isHidden=!0);for(m=this.backgrounds.length-1;m>=0;m--)o=this.backgrounds[m],s=o.isFixed?0:1,u=this.options.horizontalScrolling?(e+o.horizontalOffset-this.viewportOffsetLeft-o.startingOffsetLeft+o.parentOffsetLeft-o.startingBackgroundPositionLeft)*(s-o.stellarRatio)+"px":o.startingValueLeft,a=this.options.verticalScrolling?(t+o.verticalOffset-this.viewportOffsetTop-o.startingOffsetTop+o.parentOffsetTop-o.startingBackgroundPositionTop)*(s-o.stellarRatio)+"px":o.startingValueTop,l(o.$element,u,a)},_startViewportDetectionLoop:function(){var e=this,t=function(){var t=e.$viewportElement.offset(),n=t!==null&&t!==r;e.viewportWidth=e.$viewportElement.width(),e.viewportHeight=e.$viewportElement.height(),e.viewportOffsetTop=n?t.top:0,e.viewportOffsetLeft=n?t.left:0};t(),this._viewportDetectionInterval=setInterval(t,this.options.viewportDetectionInterval)},_startAnimationLoop:function(){var e=this,n=function(){return t.requestAnimationFrame||t.webkitRequestAnimationFrame||t.mozRequestAnimationFrame||t.oRequestAnimationFrame||t.msRequestAnimationFrame||function(e,n){t.setTimeout(e,1e3/60)}}();this._animationLoop=function(){n(e._animationLoop),e._repositionElements()},this._animationLoop()}},e.fn[i]=function(t){var n=arguments;if(t===r||typeof t=="object")return this.each(function(){e.data(this,"plugin_"+i)||e.data(this,"plugin_"+i,new d(this,t))});if(typeof t=="string"&&t[0]!=="_"&&t!=="init")return this.each(function(){var r=e.data(this,"plugin_"+i);r instanceof d&&typeof r[t]=="function"&&r[t].apply(r,Array.prototype.slice.call(n,1)),t==="destroy"&&e.data(this,"plugin_"+i,null)})},e[i]=function(n){var r=e(t);return r.stellar.apply(r,Array.prototype.slice.call(arguments,0))},e[i].scrollProperty=o,e[i].positionProperty=u,t.Stellar=d})(jQuery,window,document);

html {
  height: 100%;
  margin: auto;
}

#nav {
  background: #FFF;
  width: 100%;
}
#nav ul {
  list-style: none;
  margin-left: 400;
  padding: 0;
  line-height: 1;
  display: block;
  zoom: 1;
}
#nav ul:after {
  content: " ";
  display: block;
  font-size: 0;
  height: 0;
  clear: both;
  visibility: hidden;
}
#nav ul li {
  display: inline-block;
  padding: 0;
  margin: 0;
}
#nav.align-left ul li {
  float: left;
}
#nav.align-center ul {
  text-align: center;
}
#nav ul li a {
  color: #000;
  text-decoration: none;
  display: block;
  padding: 15px 25px;
  font-family: 'Open Sans', sans-serif;
  font-weight: 700;
  text-transform: uppercase;
  font-size: 14px;
  position: relative;
  -webkit-transition: color .25s;
  -moz-transition: color .25s;
  -ms-transition: color .25s;
  -o-transition: color .25s;
  transition: color .25s;
}
#nav ul li a:hover {
  color: #333333;
}
#nav ul li a:hover:before {
  width: 100%;
}
#nav ul li a:after {
  content: "";
  display: block;
  position: absolute;
  right: -3px;
  top: 19px;
  height: 6px;
  width: 6px;
  background: #ffffff;
  opacity: .5;
}
#nav ul li a:before {
  content: "";
  display: block;
  position: absolute;
  left: 0;
  bottom: 0;
  height: 3px;
  width: 0;
  background: #333333;
  -webkit-transition: width .25s;
  -moz-transition: width .25s;
  -ms-transition: width .25s;
  -o-transition: width .25s;
  transition: width .25s;
}
#nav ul li.last > a:after,
#nav ul li:last-child > a:after {
  display: none;
}
#nav ul li.active a {
  color: #333333;
}
#nav ul li.active a:before {
  width: 100%;
}
#nav.align-right li.last > a:after,
#nav.align-right li:last-child > a:after {
  display: block;
}
#nav.align-right li:first-child a:after {
  display: none;
}

#home{
  background-color:#06A;
  width: 100%;
  height: auto;
}

#home, #um{ width: 100%; }
#home{
background:url('http://i.imgur.com/9EaNaJb.jpg') 50% 0 no-repeat fixed;
color: #fff;
height: 600px;
margin: 0;
padding: 200px 0 260px 0;
background-size: cover;
}
#um{
background-color: #040;
color: #333333;
height: 300px;
margin: 0 auto;
overflow: hidden;
padding: 200px 0;
}

<div id="nav">
  <nav>
    <ul>
        <li><a href="#home">Home</a></li>
        <li><a href="#um">Sobre Mim</a></li>
        <li><a href="#dois">Galeria</a></li>
        <li><a href="#tres">Contato</a></li>
    </ul>
 </nav>
 
 <div id="home">
  <div id="um">
</div>