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HTML

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About the <head>

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CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

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JavaScript

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JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

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Babel includes JSX processing.

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HTML 

              
                <section>
  <figure>
    <img src="https://cdn1.iconfinder.com/data/icons/splash-of-fruit/128/fruiticons_buttons_apple-512.png" alt="">
  </figure>
  <article>
    <h3>Apple</h3>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Sapiente tempore magni consequuntur sit optio dignissimos sequi nihil. Ipsum cumque, tenetur enim reprehenderit voluptatum excepturi placeat totam cupiditate minima fuga eius!</p>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Maxime neque, dolores aliquid placeat eligendi nam libero perferendis corrupti illum velit. Animi provident quae sunt ut sit, consequatur vel eaque fugiat.</p>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto?</p>
     <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto?</p>
  </article>
</section>

<section>
  <figure>
    <img src="https://cdn1.iconfinder.com/data/icons/splash-of-fruit/128/fruiticons_buttons_lemon-512.png" alt="">
  </figure>
  <article>
    <h3>Lemon</h3>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Sapiente tempore magni consequuntur sit optio dignissimos sequi nihil. Ipsum cumque, tenetur enim reprehenderit voluptatum excepturi placeat totam cupiditate minima fuga eius!</p>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Maxime neque, dolores aliquid placeat eligendi nam libero perferendis corrupti illum velit. Animi provident quae sunt ut sit, consequatur vel eaque fugiat.</p>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto?</p>
     <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto?</p>
  </article>
</section>

<section>
  <figure>
    <img src="https://cdn1.iconfinder.com/data/icons/splash-of-fruit/128/fruiticons_buttons_watermelon-512.png" alt="">
  </figure>
  <article>
    <h3>Watermelon</h3>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Sapiente tempore magni consequuntur sit optio dignissimos sequi nihil. Ipsum cumque, tenetur enim reprehenderit voluptatum excepturi placeat totam cupiditate minima fuga eius!</p>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Maxime neque, dolores aliquid placeat eligendi nam libero perferendis corrupti illum velit. Animi provident quae sunt ut sit, consequatur vel eaque fugiat.</p>
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto?</p>
     <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto? Lorem ipsum dolor sit amet consectetur adipisicing elit. Laudantium odit voluptatem cupiditate autem voluptate incidunt numquam beatae! Possimus nulla autem quisquam recusandae sunt beatae ab odit cupiditate quam sapiente! Iusto?</p>
  </article>
</section>
!

CSS 

              
                body, html {
  height: 100%;
  margin: 0;
}

body {
  background: #d8f7ff;
  font-family: 'Montserrat';
}

section {
  display: grid;
  grid-template-columns: 30% auto;
}

figure {
  background: #bbe2ed;
  margin: 0;
}

img {
  width: 100%;
  max-width: 250px;
  display: block;
  margin: 0 auto;
  position: sticky;
  top: 20px;
}

article {
  padding: 2em;
  width: 100%;
  max-width: 500px;
  margin: 0 auto;
}

h3 {
  font-size: 3em;
  margin-top: 0;
}

p {
  line-height: 2em;
}

.entered {
	-webkit-animation: flip-scale-2-ver-left 0.5s linear both;
	        animation: flip-scale-2-ver-left 0.5s linear both;
}

/* ----------------------------------------------
 * Generated by Animista on 2018-6-26 15:46:48
 * w: http://animista.net, t: @cssanimista
 * ---------------------------------------------- */

/**
 * ----------------------------------------
 * animation flip-scale-2-ver-left
 * ----------------------------------------
 */
@-webkit-keyframes flip-scale-2-ver-left {
  0% {
    -webkit-transform: translateX(0) rotateY(0) scale(1);
            transform: translateX(0) rotateY(0) scale(1);
    -webkit-transform-origin: 0% 50%;
            transform-origin: 0% 50%;
  }
  50% {
    -webkit-transform: translateX(-50%) rotateY(90deg) scale(2);
            transform: translateX(-50%) rotateY(90deg) scale(2);
    -webkit-transform-origin: 50% 50%;
            transform-origin: 50% 50%;
  }
  100% {
    -webkit-transform: translateX(-100%) rotateY(180deg) scale(1);
            transform: translateX(-100%) rotateY(180deg) scale(1);
    -webkit-transform-origin: 100% 50%;
            transform-origin: 100% 50%;
  }
}
@keyframes flip-scale-2-ver-left {
  0% {
    -webkit-transform: translateX(0) rotateY(0) scale(1);
            transform: translateX(0) rotateY(0) scale(1);
    -webkit-transform-origin: 0% 50%;
            transform-origin: 0% 50%;
  }
  50% {
    -webkit-transform: translateX(-50%) rotateY(90deg) scale(2);
            transform: translateX(-50%) rotateY(90deg) scale(2);
    -webkit-transform-origin: 50% 50%;
            transform-origin: 50% 50%;
  }
  100% {
    -webkit-transform: translateX(-100%) rotateY(180deg) scale(1);
            transform: translateX(-100%) rotateY(180deg) scale(1);
    -webkit-transform-origin: 100% 50%;
            transform-origin: 100% 50%;
  }
}
!

JS 

              
                /*
* enter-view.js is library
*/

(function(factory) {
  if (typeof define === 'function' && define.amd) {
    define(factory);
  } else if (typeof module !== 'undefined' && module.exports) {
    module.exports = factory();
  } else {
    window.enterView = factory.call(this);
  }
})(() => {
  const lib = ({ selector, enter, exit, offset = 0, once = false }) => {
    let raf = null;
    let ticking = false;
    let elements = [];
    let height = 0;

    function setupRaf() {
      raf =
        window.requestAnimationFrame ||
        window.webkitRequestAnimationFrame ||
        window.mozRequestAnimationFrame ||
        window.msRequestAnimationFrame ||
        function(callback) {
          return setTimeout(callback, 1000 / 60);
        };
    }

    function getOffsetHeight() {
      if (offset && typeof offset === 'number') {
        const fraction = Math.min(Math.max(0, offset), 1);
        return height - fraction * height;
      }
      return height;
    }

    function updateHeight() {
      const cH = document.documentElement.clientHeight;
      const wH = window.innerHeight || 0;
      height = Math.max(cH, wH);
    }

    function updateScroll() {
      ticking = false;
      const targetFromTop = getOffsetHeight();

      elements = elements.filter(el => {
        const rect = el.getBoundingClientRect();
        const top = rect.top;
        const entered = top < targetFromTop;
        if (entered && !el.__enter_view) {
          enter(el);
          if (once) return false;
        } else if (!entered && el.__enter_view && exit) exit(el);

        el.__enter_view = entered;
        return true;
      });

      if (!elements.length) {
        window.removeEventListener('scroll', onScroll, true);
      }
    }

    function onScroll() {
      if (!ticking) {
        ticking = true;
        raf(updateScroll);
      }
    }

    function onResize() {
      updateHeight();
      updateScroll();
    }

    function selectionToArray(selection) {
      const len = selection.length;
      const result = [];
      for (let i = 0; i < len; i += 1) {
        result.push(selection[i]);
      }
      return result;
    }

    function selectAll(selector, parent = document) {
      if (typeof selector === 'string') {
        return selectionToArray(parent.querySelectorAll(selector));
      } else if (selector instanceof NodeList) {
        return selectionToArray(selector);
      } else if (selector instanceof Array) {
        return selector;
      }
    }

    function setupElements() {
      elements = selectAll(selector);
    }

    function setupEvents() {
      window.addEventListener('resize', onResize, true);
      window.addEventListener('scroll', onScroll, true);
      onResize();
    }

    function init() {
      const valid = selector && enter;
      if (!valid) console.error('must set selector and enter options');
      setupRaf();
      setupElements();
      setupEvents();
      updateScroll();
    }

    init();
  };

  return lib;
});

enterView({
	selector: 'img',
	enter: function(el) {
		el.classList.add('entered');
	}
});
!
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