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HTML

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HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

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About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

!
Insecure Resource

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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

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

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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 

              
                <div class="container overflow-hidden text-center">
  <div class="row my-5">
    <div class="col-12">
      <h1 class="display-3">
        PureJS Counter<br />
        <small class="display-6">
          ...scroll down to start the counter...
        </small>
      </h1>
    </div>
  </div>
  <div class="row extra-height row-cols-2 row-cols-lg-5 g-2 g-lg-3">
    <div class="col-4 bg-info text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true"
          data-counter-after="<small>%</small>" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
    <div class="col-4 bg-info text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-after="<small>$</small>" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
    <div class="col-4 bg-info text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-before="$" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
  </div>

  <div class="row extra-height row-cols-2 row-cols-lg-5 g-2 g-lg-3">
    <div class="col-4 bg-warning text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-after="<small>%</small>" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
    <div class="col-4 bg-warning text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-after="<small>$</small>" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
    <div class="col-4 bg-warning text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-before="$" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
  </div>

  <div class="row extra-height row-cols-2 row-cols-lg-5 g-2 g-lg-3">
    <div class="col-4 bg-success text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-after="<small>%</small>" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
    <div class="col-4 bg-success text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-after="<small>$</small>" 
          data-counter-step="0"
          data-counter-start="0"
          >
        100
      </h2>
    </div>
    <div class="col-4 bg-success text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-before="$" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
  </div>
  <div class="row extra-height row-cols-2 row-cols-lg-5 g-2 g-lg-3">
    <div class="col-4 bg-secondary text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true"
          data-counter-after="<small>%</small>" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
    <div class="col-4 bg-secondary text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-after="<small>$</small>" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
    <div class="col-4 bg-secondary text-white border d-flex align-items-center justify-content-center">
      <h2 class="text-center" 
          data-counter="true" 
          data-counter-before="$" 
          data-counter-step="0" 
          data-counter-start="0"
          >
        100
      </h2>
    </div>
  </div>

</div>
!

CSS 

              
                .extra-height {
  height: 800px;
}
h2 {
  font-size: 4rem;
}

.bg-info, .bg-warning, .bg-success, .bg-secondary {
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
}

.bg-info {
  background-image:  url(https://img.freepik.com/darmowe-zdjecie/artystyczne-rozmyte-kolorowe-tapety-tlo_58702-8663.jpg);
}

.bg-warning {
  background-image:  url(https://img.freepik.com/darmowe-zdjecie/streszczenie-rozowa-mgla-z-bitami_23-2148101934.jpg);
}

.bg-success {
  background-image:  url(https://img.freepik.com/darmowe-zdjecie/vintage-grunge-niebieski-beton-tekstura-tlo-sciany-z-winiety_1258-28373.jpg);
}

.bg-secondary {
  background-image:  url(https://img.freepik.com/darmowe-zdjecie/stare-czarne-tlo-grunge-tekstur-tablica-szkolna-tablica-beton_1258-52289.jpg);
}
!

JS 

              
                document.addEventListener("DOMContentLoaded", function() {
  function counterStartUp(element) {
    let start = parseInt(element.getAttribute("data-counter-start")) || 0;
    let end = parseInt(element.textContent) || 100;
    let step = parseInt(element.getAttribute("data-counter-step")) || 1;
    let counterAfter = element.getAttribute("data-counter-after") || "";
    let counterBefore = element.getAttribute("data-counter-before") || "";
    let duration = parseInt(element.getAttribute("data-counter-duration")) || 4000; 
    let interval = Math.ceil(duration / (end - start) * step);

    // Counter animation function
    let counter = start;
    let intervalId = setInterval(function() {
      counter += step;
      if (counter >= end) {
        counter = end; 
        clearInterval(intervalId);
        element.innerHTML = counterBefore + counter + counterAfter; 
      } else {
        element.innerHTML = counterBefore + counter + counterAfter;
      }
    }, interval);
  }
  
    // Intersection Observer to trigger counterStartUp when element enters the viewport
  const observer = new IntersectionObserver((entries) => {
    entries.forEach(entry => {
      if (entry.isIntersecting) {
        counterStartUp(entry.target);
        observer.unobserve(entry.target);
      }
    });
  }, { threshold: 0.5 }); // Trigger when 50% of the element is visible

  // Select elements with data-counter="true" and observe them
  document.querySelectorAll('[data-counter="true"]').forEach(function(element) {
    observer.observe(element);
  });
});
!
999px

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