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HTML

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Adding Classes

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About the <head>

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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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JavaScript

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Babel includes JSX processing.

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HTML 

              
                <div class="content">
  <div class="tabWrapper">
    <div class="tabs">
        <div role="tablist" aria-label="tabs">
          <button role="tab" aria-selected="true" id="tab-1">
            Tab 1
          </button>
          <button role="tab" aria-selected="false" id="tab-2">Tab 2
          </button>
          <button role="tab" aria-selected="false" id="tab-3">
            Tab 3
          </button>
        </div>
        <div role="tabpanel" aria-labelledby="tab-1">
          <h3>Tab 1</h3>
          <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla mattis nec nisi tempus scelerisque. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam ut nisl ante. Vivamus bibendum erat eu blandit congue. Mauris posuere mi eu enim finibus vestibulum. Nam lectus risus, ultricies quis libero sit amet, congue aliquam nisl. Nullam venenatis eros rhoncus venenatis faucibus. Nulla pellentesque posuere maximus. Nulla odio libero, bibendum a auctor sit amet, luctus ac mi. Praesent ipsum nunc, rhoncus sit amet malesuada quis, sollicitudin ut ante. Maecenas nec risus eleifend, tincidunt metus at, venenatis arcu. Morbi quis hendrerit magna, scelerisque euismod massa. Suspendisse sed auctor lorem. Nunc et eros tortor. Donec scelerisque nibh non dui ullamcorper, sit amet pharetra urna lobortis. Mauris pretium dolor molestie mattis porta.</p>
        </div>
        <div role="tabpanel" aria-labelledby="tab-2" hidden>
          <h3>Tab 2</h3>
          <p>Pellentesque tristique luctus eros vitae pulvinar. Nam eleifend lacus ut odio viverra mattis. Vestibulum sed sapien tellus. Orci varius natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Sed convallis, nibh nec sollicitudin dignissim, tellus tortor iaculis felis, vitae tincidunt augue nibh et erat. Etiam suscipit sapien dolor, quis placerat ex iaculis tincidunt. Nam egestas semper odio, et tempus diam tincidunt eget. Aenean ac purus libero. Etiam egestas tempor lacus vel pretium. Donec in ipsum nec enim commodo pretium. Vivamus ut vulputate magna. Donec ullamcorper justo finibus, efficitur dolor a, dapibus purus. Nam malesuada gravida nisl eget placerat. Aenean diam urna, aliquet a odio ut, luctus condimentum diam. In elementum sagittis elit, sed dapibus velit congue quis. Pellentesque cursus vulputate egestas.</p>
        </div>
        <div role="tabpanel" aria-labelledby="tab-3" hidden>
          <h3>Tab 3</h3>
          <p>Cras in risus sit amet ex auctor imperdiet. Aenean posuere interdum dui sed maximus. Vivamus volutpat rutrum consequat. Aliquam lobortis ornare vehicula. Pellentesque sollicitudin ut lorem ut accumsan. Praesent in justo mattis, mattis ipsum dignissim, consectetur sem. Aliquam blandit ullamcorper maximus. Etiam facilisis ut ex vitae scelerisque. Mauris luctus libero eu diam lobortis, sed posuere ligula imperdiet. Vestibulum sem elit, rutrum vel sollicitudin nec, luctus vitae mi. Proin imperdiet finibus mauris ac eleifend. Aliquam erat volutpat. Sed hendrerit, tortor placerat efficitur pellentesque, risus nisi tincidunt quam, id cursus diam leo non ante. Quisque ac augue tortor. Cras ac felis vel neque ornare mattis a ac tortor.</p>
        </div>
      </div>
  </div>
</div>
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CSS 

              
                $lightGrey: #F2F2F2;
$white: #FFFFFF;
$blue: #1849AB;
$black: #000000;

body {
  align-content: center;
  background: $lightGrey;
  display: flex;
  justify-content: center;
  line-height: 2;
  min-height: 100vh;
}
  
.tabs {
  display: grid;
}

[role="tablist"] {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  grid-gap: 10px;
}

.tabWrapper {
  display: grid;
  font-family: 'Arial';
  margin-top: 4rem;
  padding: 1rem;
  width: 1000px;
}

[role="tabpanel"] {
  background: $white;
  padding: 2rem;
}

button {
  background: $blue;
  border: 0;
  border-radius: 5px 5px 0 0;
  color: $white;
  cursor:pointer;
  font-size: 1rem;
  height: 40px;
}

button[aria-selected="true"] {
  background: $white;
  color: $black;
}

button:focus {
  box-shadow: 0 0 0 4px rgba(21, 156, 228, 0.7);
  outline: none;
  z-index: 5;
}
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JS 

              
                const tabs = document.querySelector('.tabs');
const tabButtons = tabs.querySelectorAll('[role="tab"]');
const tabPanels = tabs.querySelectorAll('[role="tabpanel"]');

function handleTabClick(event) {
  tabPanels.forEach(function(panel) {
    panel.hidden = true;
  });

  tabButtons.forEach(function(tab) {
    tab.setAttribute('aria-selected', false);
  });

  event.currentTarget.setAttribute('aria-selected', true);

  const {id} = event.currentTarget;

  const tabPanel = tabs.querySelector(`[aria-labelledby="${id}"]`);
  tabPanel.hidden = false;
}

tabButtons.forEach(button => button.addEventListener('click', handleTabClick));
!
999px

Console