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HTML

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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.

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About Vendor Prefixing

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JavaScript

About JavaScript Preprocessors

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

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Babel includes JSX processing.

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HTML 

              
                <h1>Different logo presenations</h1>
<p>Read an article about <a href="http://accessibilitymaker.com/accessible-high-contrast-logos/">high contrast images</a>.</p>
<h2>Option 1: High contrast logo using a white background as a part of the image file... not css</h2>
                        <img alt="" itemscope="itemscope" src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/opaqueLogo.png" role="presentation" aria-hidden="true">
                        <span role="presentation" aria-hidden="true" class="sr-only">company name</span>
                    </a>
<h2>Option 2: High Contrast logo using media queries in the &ltpicture&gt element</h2>
<p>This technique uses the picture element and media queries</p>
<a href="#logo" class="logo" aria-label="Company name">
<picture>
    <source srcset="https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/blackLogo.png" media="(-ms-high-contrast: black-on-white)">
  <source srcset="https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/whiteLogo.png" media="(-ms-high-contrast: white-on-black)">
  <source srcset="https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/opaqueLogo.png" media="(-ms-high-contrast: active)">
  <img alt="company name" src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/normalLogo.png" />
</picture>
</a>
<h2>Option 3: High contrast logo using css media queries</h2>
<a href="#logo" class="picture"><span class="sr-only">logo name</span></a>
<h2>Option 4: (Not recommended) Transparent logo using a white css background image</h2>
<p>This is an example to show the a css background cannot be used to apply a color behind a transparent image.</p>
<a href="#logo" class="backgroundImage"><img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/normalLogo.png" /></a>
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CSS 

              
                .picture:after{
  content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/normalLogo.png");
}
.backgroundImage{
  background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/white.PNG);
  background-color:#FFFFFF;
}
@media screen and (-ms-high-contrast: active){
  .picture:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/opaqueLogo.jpg");
  }
  .backgroundImage{
  background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/white.PNG);
    background-color:#FFFFFF;
}
}
@media screen and (-ms-high-contrast: black-on-white){
  .picture:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/blackLogo.png");
  }
  .backgroundImage{
  background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/white.PNG);
    background-color:#FFFFFF;
}
}
@media screen and (-ms-high-contrast: white-on-black){
  .picture:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/whiteLogo.png");
  }
  .backgroundImage{
  background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/white.PNG);
    background-color:#FFFFFF;
}
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* CSS Media Queries*/

.picture:after{
  content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/normalLogo.png");
}

@media screen and (-ms-high-contrast: active){
  .picture:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/opaqueLogo.png");
  }
}

@media screen and (-ms-high-contrast: black-on-white){
  .picture:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/blackLogo.png");
  }
}


@media screen and (-ms-high-contrast: white-on-black){
  .picture:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/whiteLogo.png");
  }
}

/* Picture element CSS to show High contrast logo in IE */

@media screen and (-ms-high-contrast: active){
  _:-ms-fullscreen, :root .logo:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/opaqueLogo.png");
  }
  _:-ms-fullscreen, :root .logo picture {
    display:none;
  }
}

@media screen and (-ms-high-contrast: black-on-white){
  _:-ms-fullscreen, :root .logo:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/blackLogo.png");
  }
  _:-ms-fullscreen, :root .logo picture {
    display:none;
  }
}

@media screen and (-ms-high-contrast: white-on-black){
  _:-ms-fullscreen, :root .logo:after{
    content: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/550792/whiteLogo.png");
  }
  _:-ms-fullscreen, :root .logo picture {
    display:none;
  }
}
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JS
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999px

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