Modelo.html

<!DOCTYPE html>
<html lang="pt-br">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Tabuada</title>
    <link rel="stylesheet" href="estilo.css">
</head>
<body>
    <Header>
        <h1>tabuada</h1>
    </Header>
        <section>
           <div>
               <p>Número: <input type="number" name="num" id="txtn">
            <input type="button" value="Gerar Tabuada" onclick="tabuada()"></p>
           </div>
      <div>
          <select name="tabuada" id="seltab" size="10"></select>
          
          <option style="text-align: center;">Digite um número acima</option>
      </div>
           
        </section>
        <footer>
            <P>&copy; Leno Rafael</P>
        </footer>
   <script src="script.js"></script>
</body>
</html> 