index.html

<!DOCTYPE html>
<html lang="en">
<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">
    <link rel="stylesheet" href="style.css">
    <title>Weather App</title>
</head>
<body>
    <div class="api">
        <div class="container">This demo needs an OpenWeather API key to work. <a target="_blank" href="https://home.openweathermap.org/users/sign_up">Get yours here for free!</a>
        </div>
      </div>
      <section class="top-banner">
        <div class="container">
          <h1 class="heading">Weather App</h1>
          <form>
            <input type="text" placeholder="Search for a city" autofocus>
            <button type="submit">SUBMIT</button>
            <span class="msg"></span>
          </form>
        </div>
      </section>
      <section class="ajax-section">
        <div class="container">
          <ul class="cities"></ul>
        </div>
      </section>
      <footer class="page-footer">
        <div class="container">
          <small>Weather App</small>
        </div>
      </footer>

    <script src="script.js"></script>
</body>
</html>