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CSS

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JavaScript

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HTML 

              
                <!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style media="screen">
  @import url("https://fonts.googleapis.com/css2?family=Poppins&display=swap");

* {
box-sizing: border-box;
}

body {
display: flex;
align-items: center;
justify-content: center;
min-height: 100vh;
margin: 0;
text-align: center;
font-family: "Poppins", sans-serif;
background: #0462a4;
}

.container {
background: #ede574; /* fallback for old browsers */
border-radius: 7px;
width: 400px;
padding: 0.5rem 2rem 2rem 2rem;
box-shadow: 0px 0px 10px #bebebe;
}

input {
font-family: "Poppins", sans-serif;
padding: 10px;
margin-bottom: 10px;
}
#enter-btn{
  background: #0472ad;
  border: none;
  padding: 12px;
  color: white;
}

.error {
color: red;
}

.successfull {
color: green;
}
  </style>
</head>
<body>
  <div class="container">
        <form action="">
          <h1>Weight Convertor</h1>
          <label for="weight-converter">KG : </label>
          <input type="text" step="5" placeholder="Enter your weight in Kg"/>
          <input type="submit" id="enter-btn" value="Enter">
          <p>Your weight in POUNDS is : <span id="convertedWeight"></span></p>
        </form>
      </div>
      <script type="text/javascript">

      const form = document.querySelector("form");

      form.addEventListener('submit', function(e) {
          e.preventDefault();
          const input = document.querySelector("input");
          var convertedWeight = document.querySelector("span");
          var kgTOpound;

          if ((isNaN(input.value)) || input.value <= 0) {
              convertedWeight.classList.add("error");
              convertedWeight.innerHTML = "<p>Please enter a valid number!</p>";

              setTimeout(() => {
                  convertedWeight.innerHTML = "";
                  convertedWeight.classList.remove("error");
              }, 2500);
              input.value = "";
          } else {
              kgTOpound = Number(input.value) * 2.20462;
              convertedWeight.classList.add("successfull");
              convertedWeight.innerHTML = `${kgTOpound.toFixed(2)}`;

              setTimeout(() => {
                  convertedWeight.innerHTML = "";
                  input.value = "";
                  convertedWeight.classList.remove("successfull");
              }, 20000);
          }
      })

      var enterInput = document.getElementById("enter-btn");
      enterInput.addEventListener("keyup", function(event) {
          if (event.keyCode === 13) {
              event.preventDefault();
              document.getElementById("enter-btn").click();
          }
      });
      </script>
</body>
</html>
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CSS
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JS
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999px

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