index.html

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width,initial-scale=1.0">
        <title>Convert</title>
        <link rel="stylesheet" href="style.css">
        <h1 class="title">UNIT CONVERTER</h1>
    </head>
    <body>
        <div class="container">
          <div class="input-container">
            <label for="kilometer"class="label">KiloMeter</label>
            <input type="number" id="km" placeholder="Kilometer"
            oninput="kilometer(parseFloat(this.value))"/>
          </div>
          <div class="input-container">
            <label for="meter" class="label">Meter </label>
            <input type="number" id="m" placeholder="Meter"
            onchange="meter(parseFloat(this.value))"/>
          </div>
          <div class="input-container">
            <label for="centimeter" class="label">Centimeter</label>
            <input type="number" id="cm" placeholder="Centimeter"
            onchange="centimeter(parseFloat(this.value))"/>
          </div>
          <div class="input-container">
            <label for="millimeter" class="label">Millimeter</label>
            <input type="number" id="mm" placeholder="Millimeter"
            onchange="millimeter(parseFloat(this.value))"/>
          </div>
        </div>
        <script src="script.js"></script>
    </body>
</html>