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HTML

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Adding Classes

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!
Insecure Resource

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CSS

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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

About 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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Packages

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HTML 

              
                <p>(Let's try to change window width)</p>

<p>Inline <code>&lt;svg&gt;</code>:</p>

<div class="svg-box">
  
  <svg class="svg-box-content" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewbox="0, 0, 200, 200">
    <defs>
      <linearGradient id="Gradient_1" gradientUnits="userSpaceOnUse" x1="252.5" y1="68.023" x2="756.5" y2="940.977" gradientTransform="matrix(0.2, 0, 0, 0.2, 0, 0)">
        <stop offset="0" stop-color="#002C3A"/>
        <stop offset="1" stop-color="#1E3307"/>
      </linearGradient>
    </defs>
    <g id="Layer_1">
      <path d="M0.1,0.1 L201.7,0.1 L201.7,201.7 L0.1,201.7 z" fill="url(#Gradient_1)"/>
    </g>
    <g id="Layer_2">
      <path d="M84.781,143.057 L111.429,72.948 L120.395,71.952 L120.395,58.877 L77.185,58.877 L77.185,71.952 L89.637,72.948 C75.566,113.42 74.32,117.28 73.075,120.891 C71.83,116.408 70.834,113.42 57.136,72.948 L69.339,71.952 L69.339,58.877 L25.132,58.877 L25.132,71.952 L33.849,72.948 L60.124,143.057 z" fill="#FCFCF2"/>
      <path d="M174.868,130.873 L165.257,130.873 L165.257,54.831 C155.527,54.951 144.715,56.994 134.985,59.637 L134.985,71.89 L146.157,71.89 L146.157,83.783 C143.273,82.701 138.468,82.221 135.345,82.221 C120.329,82.221 106.514,91.231 106.514,115.136 C106.514,134.117 116.605,145.169 130.059,145.169 C136.666,145.169 142.312,142.526 147.118,138.081 L148.199,145.049 C157.209,145.049 167.299,144.208 174.868,142.646 z M146.157,127.149 C142.312,129.191 138.949,130.152 136.546,130.152 C130.66,130.152 126.095,127.029 126.095,114.175 C126.095,100.36 132.222,97.838 138.348,97.838 C140.511,97.838 143.273,98.078 146.157,98.679 z" fill="#FCFCF2"/>
    </g>
  </svg>

</div>
!

CSS 

              
                /* Needed for Internet Explorer */ 

.svg-box {
    width: 100%;
    height: 0;
    padding-top: 100%; /* Aspect ratio */ 
    position: relative;
}

.svg-box-content {
    position: absolute;
    top: 0;
    left: 0;
}

/* etc */

body {
  margin: 2em;
}
!

JS
!
999px

Console