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CSS

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HTML 

              
                .container
  .explainer
    %h2.explain1 Here is the DOM
    %h2.explain2.visually-hidden We make a copy in JavaScript called the Virtual DOM
    %h2.explain3.visually-hidden We do this because touching the DOM with JavaScript is computationally expensive.
    %h2.explain4.visually-hidden While performing updates in JavaScript is cheap,
    %h2.explain5.visually-hidden Finding the required DOM nodes and updating them with JS is expensive
    %h2.explain6.visually-hidden So we batch calls, and change the DOM all at once.
    %h2.explain7.visually-hidden The virtual DOM in is a lightweight JavaScript object, created by this render function
    %h2.explain8.visually-hidden It takes three arguments: the element, an object with data, props, attrs and more, and an array
    %h2.explain9.visually-hidden The array is where we pass in the children, which have all these arguments too
    %h2.explain10.visually-hidden Here’s the text in the div
    %h2.explain11.visually-hidden And it’s child, the ul
    %h2.explain12.visually-hidden Now in turn it’s children, the lis
    %h2.explain13.visually-hidden If we need to update the list items, we do so in javascript
    %h2.explain14.visually-hidden And only then do we update the actual DOM
    %h2.explain15.visually-hidden The Virtual DOM allows us to make performant update our UIs! ✨
  %h3.domtext The DOM
  .text.dom
    %span This is a webpage. This webpage has some text in a p tag. Below is a list:
    %ul
      %li.firstli.dom-last-li Thing
      %li.dom-last-li Another thing
    %span It's fun to make websites with Vue you know? Some more text.
  %h3.vdomtext The Virtual DOM
  .text.vdom
    %span.last-text This is a webpage. This webpage has some text in a p tag. Below is a list:
    %ul.last-ul
      %li.firstli.last-li.update-li Thing
      %li.last-li.update-li Another thing
    %span.last-text It's fun to make websites with Vue you know? Some more text.
  %svg.gear{:height => "75", :viewbox => "0 0 90 90", :width => "75", :xmlns => "http://www.w3.org/2000/svg"}
    %g
      %g.geararrows
        %path{:d => "M45.5,77.8c-14.8,0-27.8-10-31.6-24.3c-0.1-0.5,0.2-1.1,0.7-1.2c0.5-0.1,1.1,0.2,1.2,0.7c3.6,13.4,15.8,22.8,29.7,22.8 c17,0,30.8-13.8,30.8-30.8c0-0.6,0.4-1,1-1s1,0.4,1,1C78.2,63.1,63.5,77.8,45.5,77.8z"}
        %path{:d => "M13.7,46c-0.6,0-1-0.4-1-1c0-18.1,14.7-32.8,32.8-32.8c13.6,0,26,8.6,30.7,21.4c0.2,0.5-0.1,1.1-0.6,1.3 c-0.5,0.2-1.1-0.1-1.3-0.6c-4.5-12-16-20.1-28.8-20.1c-17,0-30.8,13.8-30.8,30.8C14.7,45.6,14.3,46,13.7,46z"}
        %path{:d => "M12.8,60c-0.1,0-0.2,0-0.3,0c-0.5-0.2-0.8-0.7-0.7-1.2l1.5-5.2c0.2-0.7,0.7-1.2,1.4-1.4c0.7-0.2,1.4,0,1.9,0.6l3.7,3.9 c0.4,0.4,0.4,1,0,1.4c-0.4,0.4-1,0.4-1.4,0l-3.7-3.9l-1.5,5.2C13.6,59.7,13.2,60,12.8,60z"}
        %path{:d => "M75.5,35.9c-0.4,0-0.8-0.1-1.1-0.4l-4.4-3c-0.5-0.3-0.6-0.9-0.3-1.4c0.3-0.5,0.9-0.6,1.4-0.3l4.4,3l0.4-5.4 c0-0.6,0.5-1,1.1-0.9c0.6,0,1,0.5,0.9,1.1L77.5,34c-0.1,0.7-0.5,1.3-1.1,1.6C76.1,35.8,75.8,35.9,75.5,35.9z"}
      %g.midgear
        %path{:d => "M63.1,41.7c-0.5-2.6-1.5-5.1-3-7.2l2.6-2.6l-4.6-4.6l-2.6,2.6c-2.1-1.5-4.6-2.5-7.2-3v-3.7h-6.6v3.7c-2.6,0.5-5.1,1.5-7.2,3 l-2.6-2.6l-4.6,4.6l2.6,2.6c-1.5,2.1-2.5,4.6-3,7.2h-3.7v6.6h3.7c0.5,2.6,1.5,5.1,3,7.2l-2.6,2.6l4.6,4.6l2.6-2.6 c2.1,1.5,4.6,2.5,7.2,3v3.7h6.6v-3.7c2.6-0.5,5.1-1.5,7.2-3l2.6,2.6l4.6-4.6l-2.6-2.6c1.5-2.1,2.5-4.6,3-7.2h3.7v-6.6H63.1z M45,54 c-5,0-9-4-9-9s4-9,9-9s9,4.1,9,9S50,54,45,54z"}
        %path{:d => "M49.3,67.9h-8.6v-3.9c-2.2-0.5-4.2-1.3-6.1-2.5l-2.8,2.8l-6.1-6.1l2.8-2.8c-1.2-1.9-2-3.9-2.5-6.1h-3.9v-8.6h3.9 c0.5-2.2,1.3-4.2,2.5-6.1l-2.8-2.8l6.1-6.1l2.8,2.8c1.9-1.2,3.9-2,6.1-2.5v-3.9h8.6v3.9c2.2,0.5,4.2,1.3,6.1,2.5l2.8-2.8l6.1,6.1 l-2.8,2.8c1.2,1.9,2,3.9,2.5,6.1h3.9v8.6h-3.9c-0.5,2.2-1.3,4.2-2.5,6.1l2.8,2.8l-6.1,6.1l-2.8-2.8c-1.9,1.2-3.9,2-6.1,2.5V67.9z M42.7,65.9h4.6v-3.6l0.8-0.1c2.5-0.4,4.8-1.4,6.8-2.8l0.7-0.5l2.5,2.5l3.2-3.2l-2.5-2.5l0.5-0.7c1.4-2.1,2.4-4.4,2.8-6.8l0.1-0.8 h3.6v-4.6h-3.6l-0.1-0.8c-0.4-2.5-1.4-4.8-2.8-6.8l-0.5-0.7l2.5-2.5l-3.2-3.2l-2.5,2.5l-0.7-0.5c-2.1-1.4-4.3-2.4-6.8-2.8l-0.8-0.1 v-3.6h-4.6v3.6l-0.8,0.1c-2.5,0.4-4.7,1.4-6.8,2.8l-0.7,0.5l-2.5-2.5l-3.2,3.2l2.5,2.5l-0.5,0.7c-1.4,2.1-2.4,4.3-2.8,6.8l-0.1,0.8 h-3.6v4.6h3.6l0.1,0.8c0.4,2.5,1.4,4.8,2.8,6.8l0.5,0.7l-2.5,2.5l3.2,3.2l2.5-2.5l0.7,0.5c2.1,1.4,4.3,2.4,6.8,2.8l0.8,0.1V65.9z M45,55c-5.5,0-10-4.5-10-10s4.5-10,10-10s10,4.5,10,10S50.5,55,45,55z M45,37c-4.4,0-8,3.6-8,8s3.6,8,8,8s8-3.6,8-8S49.4,37,45,37z"}
  .code
    %span.keyword export default function
    = succeed "()" do
      %span.func render
    %br/
    %span.sp.keyword return
    (
    %span.func> openBlock
    (),
    = succeed "(" do
      %span.func createBlock
    %br/
    %span.fn-el.visually-hidden
      %span.sp
      = succeed "," do
        %span.sp.string "div"
      %span.comment //element
      %br/
    %span.fn-state.visually-hidden
      %span.sp
      = succeed "{}," do
        %span.sp
      %span.comment.sp //state, props, style, attrs
      %br/
    %span.fn-arr1.visually-hidden
      %span.sp
      = succeed "[...]" do
        %span.sp
      %span.comment //children
      %br/
    %span.fn-arr2.visually-hidden
      %span.sp
      = succeed "[" do
        %span.sp
      %br/
      %span.last-text
        %span.sp
        %span.sp
        %span.sp
        = succeed "(" do
          %span.func createTextVNode
        = succeed ")," do
          %span.string "This is a webpage...."
      %br/
      %span.last-ul
        %span.sp
        %span.sp
        %span.sp
        = succeed "(" do
          %span.func createVNode
        = succeed "," do
          %span.string "ul"
      %br/
      %span.last-li
        %span.sp
        %span.sp
        %span.sp
        %span.sp
        = succeed "(" do
          %span.func createVNode
        = succeed "," do
          %span.string "li"
        = succeed ")," do
          %span.string
            "
            %span.update-li> Thing One
            "
      %br/
      %span.last-li
        %span.sp
        %span.sp
        %span.sp
        %span.sp
        = succeed "(" do
          %span.func createVNode
        = succeed "," do
          %span.string "li"
        = succeed ")" do
          %span.string
            "
            %span.update-li> Another thing
            "
      %br/
      %span.sp
      %span.sp
      = succeed "])," do
        %span.sp
      %br/
      %span.last-text
        %span.sp
        %span.sp
        %span.sp
        = succeed "(" do
          %span.func createTextVNode
        = succeed ")" do
          %span.string "It's fun to make websites..."
      %br/
      %span.sp
      = succeed "]" do
        %span.sp
      %br/
    = succeed "))" do
      %span.sp
    %br/
    }
    %br/
!

CSS 

              
                body {
  -ms-text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  font-family: 'Source Sans Pro', sans-serif;
  color: #4f5959;
}

* { box-sizing: border-box; }

.container {
  position: relative;
  margin: 0 80px;
}

.text {
  position: absolute;
  width: 300px;
  font-size: 18px;
  padding: 30px;
  box-shadow: -5px 18px 40px -12px rgba(0, 0, 0, 0.4);
  transform: perspective(800px) rotateY(30deg) rotateX(15deg) rotate(-2deg) scaleX(0.95);
  backface-visibility: hidden;
}

.explainer, .vdom, .vdomtext, .gear, .code {
  visibility: hidden;
}

.explainer div {
  transform-origin: 50% 50%;
}

.visually-hidden { 
  position: absolute !important;
  height: 1px; 
  width: 1px;
  overflow: hidden;
  clip: rect(1px, 1px, 1px, 1px);
  white-space: nowrap;
}

h2 {
  color: #273849;
  text-align: center;
  margin-top: 40px;
  font-size: 28px;
}

h3, .code, pre, code {
  font-family: 'Roboto Mono', monospace;
  font-size: 15px;
}

h3 {
  color: rgb(66, 185, 131);
}

.domtext {
  margin-left: 80px;
}

.vdomtext {
  position: absolute;
  top: 60px;
  margin-left: 400px;
}

.explainer {
  margin-bottom: 40px;
}

.active {
  border: 1px dashed #db443c;
  background: #c84f491f;
  color: #c40e05;
}

.gear {
  position: absolute;
  padding: 5px;
  top: 150px;
  left: 260px;
}

.midgear {
  fill: #42b983;
}

.geararrows {
  fill: #a7d6c0;
}

//code
.code, pre, code {
  font-family: 'Roboto Mono', monospace;
  font-size: 15px;
}

.string {
  color: #42b983;
}

.keyword {
  color: #d63200;
}

.func {
  color: #2973b7;
}

.sp {
  margin-left: 20px;
}

.comment {
  color: #848484;
}

.code {
  position: absolute;
  top: 80px;
  margin-left: 750px;
  line-height: 1.3;
}
!

JS 

              
                gsap.set('.explainer, .vdom, .vdomtext, .gear, .code', {
  visibility: 'visible'
})

//-------------//
//  helpers    //
//-------------//

const hideShow = (el1, el2) => {
  let elref1 = document.querySelector(el1)
  elref1.classList.add('visually-hidden')
  
  let elref2 = document.querySelector(el2)
  elref2.classList.remove('visually-hidden')
}

const showElement = (el) => {
  let elref = document.querySelector(el)
  elref.classList.remove('visually-hidden')
}

const updateText = (el, text) => {
  let elref = document.querySelectorAll(el)
  
  elref.forEach(function(el) {
    el.innerHTML = text
  });
}

const animateHeading = (tl, el1, el2, delay1, delay2) => {
   tl.to(`${el1} div`, { 
      opacity: 0, 
      scaleX: 0, 
      duration: 0.1,
      stagger: 0.01,
      ease: 'sine.in' 
    }, delay1) 
    tl.call(hideShow, [el1, el2])
    tl.to(`${el2} div`, { 
      opacity: 1, 
      scaleX: 1, 
      duration: 0.4,
      delay: delay2,
      stagger: 0.02,
      ease: 'sine' 
    }) 
    return tl
}

//------------------------//
//  scene one, plus text  //
//------------------------//

const explainText = new SplitText('.explainer', { type: 'words, chars' });

gsap.set('.explainer h2 div', {
  opacity: 0,
  scaleX: 0
})

gsap.set('.vdom, .vdomtext, .gear, .code, .fn-el, .fn-state, .fn-arr1, .fn-arr2', {
  opacity: 0
})

const scene1 = () => {
  const tl1 = gsap.timeline({
    delay: 0.7
  })
  
  tl1.to('.explain1 div', { 
      opacity: 1, 
      scaleX: 1, 
      duration: 0.4,
      delay: 0.5,
      stagger: 0.03,
      ease: 'sine' 
    }) 
  tl1.call(animateHeading, [tl1, '.explain1', '.explain2', '-=1.5', 0])
  tl1.add('vdomcreate', '+=1')
  tl1.to('.vdom', { 
      opacity: 1, 
      duration: 0.3,
      ease: 'sine' 
    }, 'vdomcreate') 
  tl1.to('.vdom', { 
      duration: 1.25,
      x: 350,
      perspective: 1200,
      rotateY: 20,
      ease: 'sine' 
    }, 'vdomcreate') 
  tl1.to('.vdomtext', { 
      opacity: 1, 
      duration: 0.35,
      ease: 'sine' 
    }) 
  tl1.call(animateHeading, [tl1, '.explain2', '.explain3', '+=2', 2])
  tl1.call(animateHeading, [tl1, '.explain3', '.explain4', '+=2', 0])
  tl1.call(animateHeading, [tl1, '.explain4', '.explain5', '+=2', 0])
  tl1.call(animateHeading, [tl1, '.explain5', '.explain6', '+=2', 0])
  tl1.call(animateHeading, [tl1, '.explain6', '.explain7', '+=2', 2])
  tl1.call(animateHeading, [tl1, '.explain7', '.explain8', '+=2', 0])
  tl1.call(animateHeading, [tl1, '.explain8', '.explain9', '+=4', 0])
  
  tl1.call(animateHeading, [tl1, '.explain9', '.explain10', '+=2', 0])
  tl1.call(animateHeading, [tl1, '.explain10', '.explain11', '+=2', 0])
  tl1.call(animateHeading, [tl1, '.explain11', '.explain12', '+=2', 0])
  
  tl1.call(animateHeading, [tl1, '.explain12', '.explain13', '+=2', 0])
  tl1.call(animateHeading, [tl1, '.explain13', '.explain14', '+=2', 0])
  tl1.call(animateHeading, [tl1, '.explain14', '.explain15', '+=2', 0])
  
  return tl1
}

//------------------//
//  scene two       //
//------------------//

const scene2 = () => {
  const tl2 = gsap.timeline({
    delay: 16,
    ease: 'sine'
  })
  
  tl2.to('.vdom .firstli', { 
    background: '#eee',
    duration: 0.4
  })
  tl2.call(updateText, ['.vdom .firstli', 'Thing One'])
  tl2.to('.vdom .firstli', { 
    background: 'none',
    ease: 'sine.easeIn',
    delay: 0.2,
    duration: 0.3
  })
  tl2.add('geardom', '+=3.5')
  //gear stuff
  tl2.to('.gear', { 
    opacity: 1,
    duration: 0.4
  }, 'geardom')
  tl2.to('.midgear', { 
    rotation: -720,
    duration: 1.5,
    transformOrigin: '50% 50%'
  }, 'geardom')
  tl2.to('.geararrows', { 
    rotation: 720,
    duration: 1.5,
     transformOrigin: '50% 50%'
  }, 'geardom')
  //dom update
  tl2.to('.dom .firstli', { 
    background: '#eee',
    duration: 0.4
  }, 'geardom')
  tl2.call(updateText, ['.dom .firstli', 'Thing One'], 'geardom')
  tl2.to('.dom .firstli', { 
    background: 'none',
    ease: 'sine.easeIn',
    delay: 0.2,
    duration: 0.3
  }, 'geardom+=0.5')
  tl2.to('.gear', { 
    opacity: 0,
    duration: 0.4,
    ease: 'sine.easeIn',
  }, 'geardom+=1.75')
  
  return tl2
}


//------------------//
//  scene three     //
//------------------//

const scene3 = () => {
  const tl3 = gsap.timeline({
    delay: 29,
    ease: 'sine'
  })
  
  tl3.to('.code', { 
    opacity: 1,
    duration: 0.4
  })
  tl3.add('children', '+=5')
  tl3.call(showElement, ['.fn-el'], 'children')
  tl3.call(showElement, ['.fn-state'], 'children')
  tl3.call(showElement, ['.fn-arr1'], 'children')
  tl3.to('.fn-el', { 
    opacity: 1,
    duration: 0.6
  }, 'children+=0.2')
  tl3.to('.fn-state', { 
    opacity: 1,
    duration: 0.6
  }, 'children+=0.7')
  tl3.to('.fn-arr1', { 
    opacity: 1,
    duration: 0.6
  }, 'children+=1.2')
  tl3.call(hideShow, ['.fn-arr1', '.fn-arr2'], 'children+=7')
  tl3.to('.fn-arr2', { 
    opacity: 1,
    duration: 0.6
  }, 'children+=7')
  
  return tl3
}

//------------------//
//  scene four      //
//------------------//

const scene4 = () => {
  const tl4 = gsap.timeline({
    delay: 45,
    ease: 'sine'
  })
  
  tl4.add('ending')
  tl4.to('.last-text', { 
    background: '#eee',
    duration: 0.75
  }, 'ending')
  tl4.to('.last-text', { 
    background: 'none',
    ease: 'sine.easeIn',
    duration: 0.25
  }, 'ending+=0.75')
  
  tl4.to('.last-ul', { 
    background: '#eee',
    duration: 0.75
  }, 'ending+=3')
  tl4.to('.last-ul', { 
    background: 'none',
    ease: 'sine.easeIn',
    duration: 0.25
  }, 'ending+=3.75')
  
  tl4.to('.last-li', { 
    background: '#eee',
    duration: 0.75
  }, 'ending+=6')
  tl4.to('.last-li', { 
    background: 'none',
    ease: 'sine.easeIn',
    duration: 0.25
  }, 'ending+=6.75')
  
  //update the list items
  tl4.to('.last-li', { 
    background: '#eee',
    duration: 0.75
  }, 'ending+=10')
  tl4.call(updateText, ['.update-li', 'New List Items!'], 'ending+=10')
  tl4.to('.last-li', { 
    background: 'none',
    ease: 'sine.easeIn',
    duration: 0.25
  }, 'ending+=10.75')
  
  
  //update the list items in the dom
  tl4.to('.dom-last-li', { 
    background: '#eee',
    duration: 0.75
  }, 'ending+=14')
  tl4.call(updateText, ['.dom-last-li', 'New List Items!'], 'ending+=14')
  tl4.to('.dom-last-li', { 
    background: 'none',
    ease: 'sine.easeIn',
    duration: 0.25
  }, 'ending+=14.75')
   //gear stuff
  tl4.to('.gear', { 
    opacity: 1,
    duration: 0.4
  }, 'ending+=14')
  tl4.to('.midgear', { 
    rotation: -1440,
    duration: 1.5,
    transformOrigin: '50% 50%'
  }, 'ending+=14')
  tl4.to('.geararrows', { 
    rotation: 1440,
    duration: 1.5,
     transformOrigin: '50% 50%'
  }, 'ending+=14')
  tl4.to('.gear', { 
    opacity: 0,
    duration: 0.4,
    ease: 'sine.easeIn',
  }, 'ending+=15.75')
  
  return tl4
}

//------------------//
//     master       //
//------------------//

window.onload = () => {
  const sceneOne = scene1()
  const sceneTwo = scene2()
  const sceneThree = scene3()
  const sceneFour = scene4()
  
  const master = gsap.timeline()
  master.add('sceneOne')
  master.add('sceneTwo')
  master.add('sceneThree')
  master.add('sceneFour')
};
!
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