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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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Adding Classes

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. So you don't have access to higher-up elements like the <html> tag. If you want to add classes there that can affect the whole document, this is the place to do it.

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.

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Insecure Resource

The resource you are linking to is using the 'http' protocol, which may not work when the browser is using https.

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-.

We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).

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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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Packages

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Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

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HTML 

              
                 <!-- tabs -->
    <div class="input-settings">
      <ul class="tabs">
        <li class="tab allow active">
          <span class="title">Allow</span>
        </li>
        <li class="tab prevent">
          <span class="title">Prevent</span>
        </li>
        <div class="slider"></div>
      </ul>
    </div>
    <!-- END tabs -->

    <!-- input -->
    <div class="wrapper">
      <input class="primary" type="text" pattern="[0-9]" />
      <span class="label">try digits</span>
    </div>
    <!--END input -->

    <!-- made in jssecrets.com -->
    <a class="jssecrets" href="https://jssecrets.com/" target="_blank"
      >jssecrets.com</a
    >
    <!-- made in jssecrets.com -->
!

CSS 

              
                @import url("https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;800&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Urbanist:wght@500&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Nanum+Pen+Script&display=swap");
*,
::before,
::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Poppins", sans-serif;
}

ul {
  list-style: none;
}

body {
  height: 100vh;
  background: hsl(225, 14%, 12%);
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  color: #292d34;
}

input.primary {
  width: 320px;
  border: 2px solid rgb(80, 121, 247);
  box-shadow: 0 4px 20px rgba(80, 121, 247, 0.4);
  color: rgb(80, 121, 247);
  background: transparent;
  outline: none;
  font-size: 24px;
  padding: 16px;
  border-radius: 12px;
  transition: all 0.8s ease-out;
  opacity: 1;
}
@media (max-width: 400px) {
  input.primary {
    width: 220px;
    padding: 8px;
  }
}

.input-settings {
  width: 320px;
  border-radius: 10px;
  background-color: hsl(225, 14%, 17%);
  border: 1.5px solid rgba(0, 0, 0, 0.38);
  box-shadow: 0 8px 32px 0 hsl(225, 14%, 12%);
  backdrop-filter: blur(40px);
  padding: 16px;
  position: absolute;
  left: 50%;
  top: 5%;
  transform: translate(-50%, -5%);
  opacity: 1;
  transition: all 0.7s ease-out;
}
@media (max-width: 400px) {
  .input-settings {
    width: 220px;
    padding: 8px;
  }
}

.tabs {
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}
.tabs .slider {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 100%;
  width: 50%;
  background: linear-gradient(45deg, rgb(245, 205, 81) 0%, rgb(247, 206, 81) 100%);
  box-shadow: 0 4px 20px rgba(245, 205, 81, 0.4);
  border-radius: 9px;
  z-index: 0;
  transition: all 0.3s linear;
}
.tabs .tab {
  width: 50%;
  height: 100%;
  display: block;
  text-align: center;
  cursor: pointer;
  padding: 16px 0 16px 0;
  border-radius: 9px;
  font-size: 16px;
  z-index: 1;
  position: relative;
  color: #7c828d;
  transition: all 0.3s linear;
}
.tabs .tab:hover {
  color: #f7ce51;
}
.tabs .tab .title {
  font-size: 16px;
}
@media (max-width: 400px) {
  .tabs .tab .title {
    font-size: 14px;
  }
}
.tabs .tab.active .title {
  font-weight: 900;
  color: hsl(225, 14%, 12%);
}
.tabs .tab:nth-of-type(1).active ~ .slider {
  left: 0%;
}
.tabs .tab:nth-of-type(2).active ~ .slider {
  left: 50%;
}

.wrapper {
  position: relative;
}
.wrapper .label {
  position: absolute;
  top: 100px;
  left: 50%;
  transform: translateX(-50%);
  color: white;
  font-family: "Nanum Pen Script", cursive;
  font-size: 32px;
}

.jssecrets {
  font-weight: 500;
  text-decoration: none !important;
  font-family: "Urbanist";
  padding: 16px;
  background: #ffc805;
  color: #000000;
  font-size: 1.2em;
  letter-spacing: 0.2px;
  border-radius: 8px;
  box-shadow: 0px 4px 12px rgba(184, 144, 0, 0.1882352941), 0px 8px 24px rgba(184, 144, 0, 0.3764705882);
  position: absolute;
  bottom: 24px;
  right: 24px;
  transition: all 0.3s;
}

.jssecrets:hover {
  transform: translateY(-4px);
}
!

JS 

              
                // Variables
const tabs = document.querySelectorAll('.tabs .tab');
const input = document.querySelector('.primary');

// Regular Expressions

// digits only
const regex = /\d/;
let allow = true;

// Functions
// 1. Set active tab
const setActiveTab = (event) => {
  // sliding tabs functionality
  document.querySelector('.tab.active').classList.remove('active');
  event.currentTarget.classList.add('active');
  //
  if (event.currentTarget.classList.contains('allow')) {
    allow = true;
  } else {
    allow = false;
  }

  // clear input
  input.value = '';
};

// 2. Input filter
const inputFilter = (event) => {
  // catch pressed key's code
  // and convert it to an actual character
  let symbol = String.fromCharCode(event.keyCode);

  if (allow) {
    if (!regex.test(symbol)) {
      event.preventDefault();
    }
  } else {
    if (regex.test(symbol)) {
      event.preventDefault();
    }
  }
};

// Event Listeners
// sliding tabs event
tabs.forEach((tab) => {
  tab.addEventListener('click', setActiveTab);
});
// input event
// input.addEventListener('keypress', inputFilter);
input.addEventListener('keypress', inputFilter);
!
999px

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