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k(a){var b=a.parentNode;return b&&11==b.nodeType&&b.host?b.host:b&&b.assignedSlot?b.assignedSlot.parentNode:b}if("object"==typeof window){if("IntersectionObserver"in window&&"IntersectionObserverEntry"in window&&"intersectionRatio"in window.IntersectionObserverEntry.prototype)return void("isIntersecting"in window.IntersectionObserverEntry.prototype||Object.defineProperty(window.IntersectionObserverEntry.prototype,"isIntersecting",{get:function(){return this.intersectionRatio>0}}));var l=window.document,m=[];b.prototype.THROTTLE_TIMEOUT=100,b.prototype.POLL_INTERVAL=null,b.prototype.USE_MUTATION_OBSERVER=!0,b.prototype.observe=function(a){var b=this._observationTargets.some(function(b){return b.element==a});if(!b){if(!a||1!=a.nodeType)throw new Error("target must be an 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Error("rootMargin must be specified in pixels or percent");return{value:parseFloat(b[1]),unit:b[2]}});return c[1]=c[1]||c[0],c[2]=c[2]||c[0],c[3]=c[3]||c[1],c},b.prototype._monitorIntersections=function(){this._monitoringIntersections||(this._monitoringIntersections=!0,this.POLL_INTERVAL?this._monitoringInterval=setInterval(this._checkForIntersections,this.POLL_INTERVAL):(e(window,"resize",this._checkForIntersections,!0),e(l,"scroll",this._checkForIntersections,!0),this.USE_MUTATION_OBSERVER&&"MutationObserver"in window&&(this._domObserver=new 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a({time:c(),target:f,boundingClientRect:g,rootBounds:d,intersectionRect:k});j?b&&i?this._hasCrossedThreshold(j,l)&&this._queuedEntries.push(l):j&&j.isIntersecting&&this._queuedEntries.push(l):this._queuedEntries.push(l)},this),this._queuedEntries.length&&this._callback(this.takeRecords(),this)},b.prototype._computeTargetAndRootIntersection=function(a,b){if("none"!=window.getComputedStyle(a).display){for(var c=h(a),d=c,e=k(a),f=!1;!f;){var i=null,j=1==e.nodeType?window.getComputedStyle(e):{};if("none"==j.display)return;if(e==this.root||e==l?(f=!0,i=b):e!=l.body&&e!=l.documentElement&&"visible"!=j.overflow&&(i=h(e)),i&&(d=g(i,d),!d))break;e=k(e)}return d}},b.prototype._getRootRect=function(){var a;if(this.root)a=h(this.root);else{var b=l.documentElement,c=l.body;a={top:0,left:0,right:b.clientWidth||c.clientWidth,width:b.clientWidth||c.clientWidth,bottom:b.clientHeight||c.clientHeight,height:b.clientHeight||c.clientHeight}}return this._expandRectByRootMargin(a)},b.prototype._expandRectByRootMargin=function(a){var b=this._rootMarginValues.map(function(b,c){return"px"==b.unit?b.value:b.value*(c%2?a.width:a.height)/100}),c={top:a.top-b[0],right:a.right+b[1],bottom:a.bottom+b[2],left:a.left-b[3]};return c.width=c.right-c.left,c.height=c.bottom-c.top,c},b.prototype._hasCrossedThreshold=function(a,b){var c=a&&a.isIntersecting?a.intersectionRatio||0:-1,d=b.isIntersecting?b.intersectionRatio||0:-1;if(c!==d)for(var e=0;e<this.thresholds.length;e++){var f=this.thresholds[e];if(f==c||f==d||c>f!=d>f)return!0}},b.prototype._rootIsInDom=function(){return!this.root||j(l,this.root)},b.prototype._rootContainsTarget=function(a){return j(this.root||l,a)},b.prototype._registerInstance=function(){m.indexOf(this)<0&&m.push(this)},b.prototype._unregisterInstance=function(){var a=m.indexOf(this);-1!=a&&m.splice(a,1)},window.IntersectionObserver=b,window.IntersectionObserverEntry=a}}();