<!DOCTYPE html>
<html lang="en-US">
  <head>
    <meta charset="utf-8">

    <title>Number guessing game</title>

    <style>
      html {
        font-family: sans-serif;
      }

      body {
        width: 50%;
        max-width: 800px;
        min-width: 480px;
        margin: 0 auto;
      }
      
      .form input[type="number"] {
        width: 200px;
      }

      .lastResult {
        color: white;
        padding: 3px;
      }
    </style>
  </head>

  <body>
    <h1>Number guessing game</h1>

 