Parallax scroll - картинка выходит за границы блока при масштабировании

$('.main').parallax({ 
  imageSrc: 'img/main/main-bg.jpg', 
  speed: '0.2' 
}) 
$('.callback').parallax({ 
  imageSrc: 'img/main/callback-bg.jpg', 
  speed: '0.2' 
}) 
$('.bonuses').parallax({ 
  imageSrc: 'img/main/bonuses-bg.jpg', 
  speed: '0.2' 
}) 
$('.creed').parallax({ 
  imageSrc: 'img/main/creed-bg.jpg', 
  speed: '0.2' 
})

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
<div id="callback" class="callback"> 
  <div class="callback-overlay"></div> 
  <div class="container"> 
    <p class="callback-header">Давайте обсудим ваш проект</p> 
    <p>Наши специалисты свяжутся с Вами в течении пяти минут</p> 
    <form id="callback-form" action="mail.php"> 
      <div class="callback-wrapper"> 
        <input name="name" type="text" placeholder="Имя"> 
        <input name="phone" type="tel" placeholder="Телефон"> 
        <input name="form" type="hidden" value="callback"> 
      </div> 
      <input type="submit" value="Перезвоните мне"> 
    </form> 
  </div> 
</div>

/*! 
 * parallax.js v1.4.2 (http://pixelcog.github.io/parallax.js/) 
 * @copyright 2016 PixelCog, Inc. 
 * @license MIT (https://github.com/pixelcog/parallax.js/blob/master/LICENSE) 
 */ 
!function(t,i,e,s){function o(i,e){var h=this;"object"==typeof e&&(delete e.refresh,delete e.render,t.extend(this,e)),this.$element=t(i),!this.imageSrc&&this.$element.is("img")&&(this.imageSrc=this.$element.attr("src"));var r=(this.position+"").toLowerCase().match(/\S+/g)||[];if(r.length<1&&r.push("center"),1==r.length&&r.push(r[0]),("top"==r[0]||"bottom"==r[0]||"left"==r[1]||"right"==r[1])&&(r=[r[1],r[0]]),this.positionX!=s&&(r[0]=this.positionX.toLowerCase()),this.positionY!=s&&(r[1]=this.positionY.toLowerCase()),h.positionX=r[0],h.positionY=r[1],"left"!=this.positionX&&"right"!=this.positionX&&(this.positionX=isNaN(parseInt(this.positionX))?"center":parseInt(this.positionX)),"top"!=this.positionY&&"bottom"!=this.positionY&&(this.positionY=isNaN(parseInt(this.positionY))?"center":parseInt(this.positionY)),this.position=this.positionX+(isNaN(this.positionX)?"":"px")+" "+this.positionY+(isNaN(this.positionY)?"":"px"),navigator.userAgent.match(/(iPod|iPhone|iPad)/))return this.imageSrc&&this.iosFix&&!this.$element.is("img")&&this.$element.css({backgroundImage:"url("+this.imageSrc+")",backgroundSize:"cover",backgroundPosition:this.position}),this;if(navigator.userAgent.match(/(Android)/))return this.imageSrc&&this.androidFix&&!this.$element.is("img")&&this.$element.css({backgroundImage:"url("+this.imageSrc+")",backgroundSize:"cover",backgroundPosition:this.position}),this;this.$mirror=t("<div />").prependTo("body");var a=this.$element.find(">.parallax-slider"),n=!1;0==a.length?this.$slider=t("<img />").prependTo(this.$mirror):(this.$slider=a.prependTo(this.$mirror),n=!0),this.$mirror.addClass("parallax-mirror").css({visibility:"hidden",zIndex:this.zIndex,position:"fixed",top:0,left:0,overflow:"hidden"}),this.$slider.addClass("parallax-slider").one("load",function(){h.naturalHeight&&h.naturalWidth||(h.naturalHeight=this.naturalHeight||this.height||1,h.naturalWidth=this.naturalWidth||this.width||1),h.aspectRatio=h.naturalWidth/h.naturalHeight,o.isSetup||o.setup(),o.sliders.push(h),o.isFresh=!1,o.requestRender()}),n||(this.$slider[0].src=this.imageSrc),(this.naturalHeight&&this.naturalWidth||this.$slider[0].complete||a.length>0)&&this.$slider.trigger("load")}function h(s){return this.each(function(){var h=t(this),r="object"==typeof s&&s;this==i||this==e||h.is("body")?o.configure(r):h.data("px.parallax")?"object"==typeof s&&t.extend(h.data("px.parallax"),r):(r=t.extend({},h.data(),r),h.data("px.parallax",new o(this,r))),"string"==typeof s&&("destroy"==s?o.destroy(this):o[s]())})}!function(){for(var t=0,e=["ms","moz","webkit","o"],s=0;s<e.length&&!i.requestAnimationFrame;++s)i.requestAnimationFrame=i[e[s]+"RequestAnimationFrame"],i.cancelAnimationFrame=i[e[s]+"CancelAnimationFrame"]||i[e[s]+"CancelRequestAnimationFrame"];i.requestAnimationFrame||(i.requestAnimationFrame=function(e){var s=(new Date).getTime(),o=Math.max(0,16-(s-t)),h=i.setTimeout(function(){e(s+o)},o);return t=s+o,h}),i.cancelAnimationFrame||(i.cancelAnimationFrame=function(t){clearTimeout(t)})}(),t.extend(o.prototype,{speed:.2,bleed:0,zIndex:-100,iosFix:!0,androidFix:!0,position:"center",overScrollFix:!1,refresh:function(){this.boxWidth=this.$element.outerWidth(),this.boxHeight=this.$element.outerHeight()+2*this.bleed,this.boxOffsetTop=this.$element.offset().top-this.bleed,this.boxOffsetLeft=this.$element.offset().left,this.boxOffsetBottom=this.boxOffsetTop+this.boxHeight;var t=o.winHeight,i=o.docHeight,e=Math.min(this.boxOffsetTop,i-t),s=Math.max(this.boxOffsetTop+this.boxHeight-t,0),h=this.boxHeight+(e-s)*(1-this.speed)|0,r=(this.boxOffsetTop-e)*(1-this.speed)|0;if(h*this.aspectRatio>=this.boxWidth){this.imageWidth=h*this.aspectRatio|0,this.imageHeight=h,this.offsetBaseTop=r;var a=this.imageWidth-this.boxWidth;this.offsetLeft="left"==this.positionX?0:"right"==this.positionX?-a:isNaN(this.positionX)?-a/2|0:Math.max(this.positionX,-a)}else{this.imageWidth=this.boxWidth,this.imageHeight=this.boxWidth/this.aspectRatio|0,this.offsetLeft=0;var a=this.imageHeight-h;this.offsetBaseTop="top"==this.positionY?r:"bottom"==this.positionY?r-a:isNaN(this.positionY)?r-a/2|0:r+Math.max(this.positionY,-a)}},render:function(){var t=o.scrollTop,i=o.scrollLeft,e=this.overScrollFix?o.overScroll:0,s=t+o.winHeight;this.boxOffsetBottom>t&&this.boxOffsetTop<=s?(this.visibility="visible",this.mirrorTop=this.boxOffsetTop-t,this.mirrorLeft=this.boxOffsetLeft-i,this.offsetTop=this.offsetBaseTop-this.mirrorTop*(1-this.speed)):this.visibility="hidden",this.$mirror.css({transform:"translate3d(0px, 0px, 0px)",visibility:this.visibility,top:this.mirrorTop-e,left:this.mirrorLeft,height:this.boxHeight,width:this.boxWidth}),this.$slider.css({transform:"translate3d(0px, 0px, 0px)",position:"absolute",top:this.offsetTop,left:this.offsetLeft,height:this.imageHeight,width:this.imageWidth,maxWidth:"none"})}}),t.extend(o,{scrollTop:0,scrollLeft:0,winHeight:0,winWidth:0,docHeight:1<<30,docWidth:1<<30,sliders:[],isReady:!1,isFresh:!1,isBusy:!1,setup:function(){if(!this.isReady){var s=t(e),h=t(i),r=function(){o.winHeight=h.height(),o.winWidth=h.width(),o.docHeight=s.height(),o.docWidth=s.width()},a=function(){var t=h.scrollTop(),i=o.docHeight-o.winHeight,e=o.docWidth-o.winWidth;o.scrollTop=Math.max(0,Math.min(i,t)),o.scrollLeft=Math.max(0,Math.min(e,h.scrollLeft())),o.overScroll=Math.max(t-i,Math.min(t,0))};h.on("resize.px.parallax load.px.parallax",function(){r(),o.isFresh=!1,o.requestRender()}).on("scroll.px.parallax load.px.parallax",function(){a(),o.requestRender()}),r(),a(),this.isReady=!0}},configure:function(i){"object"==typeof i&&(delete i.refresh,delete i.render,t.extend(this.prototype,i))},refresh:function(){t.each(this.sliders,function(){this.refresh()}),this.isFresh=!0},render:function(){this.isFresh||this.refresh(),t.each(this.sliders,function(){this.render()})},requestRender:function(){var t=this;this.isBusy||(this.isBusy=!0,i.requestAnimationFrame(function(){t.render(),t.isBusy=!1}))},destroy:function(e){var s,h=t(e).data("px.parallax");for(h.$mirror.remove(),s=0;s<this.sliders.length;s+=1)this.sliders[s]==h&&this.sliders.splice(s,1);t(e).data("px.parallax",!1),0===this.sliders.length&&(t(i).off("scroll.px.parallax resize.px.parallax load.px.parallax"),this.isReady=!1,o.isSetup=!1)}});var r=t.fn.parallax;t.fn.parallax=h,t.fn.parallax.Constructor=o,t.fn.parallax.noConflict=function(){return t.fn.parallax=r,this},t(e).on("ready.px.parallax.data-api",function(){t('[data-parallax="scroll"]').parallax()})}(jQuery,window,document);