I am not sure how to centre the password input field, password text and submit button. I've tried text-align centre but I'm new and don't have enough experience to know a different way to do it. 
Any help is appreciated!
note: if you refresh the page too often the api gets limited and the GIF disappears, i wouldve just changed it to an image for this question but i thought that might have something to do with it.
<!doctype HTML>
<html>
<head>
    <meta name="websiteinnit" content="width=device-width, initial-scale=1">
    <link rel=icon href="https://i.imgur.com/zWdbQf2.png">
  <script src="http://code.jquery.com/jquery-2.1.1.min.js"></script>
  <script>
  $(function() {
    var xhr = $.get("http://api.giphy.com/v1/gifs/random?api_key=dc6zaTOxFJmzC&tag=no");
    xhr.done(function(data) { 
      $('.gif-bg').css('background-image', 'url(' + data.data.image_url + ')');
    });
  });
  </script>
</head>
<body>
  <div class = "usernamecss">
  
<div class = "passwordcss">
<label class = "password" for = "password">Password:</label><br>
<input class = "passwordinput" type= "Password" id="password" name="password">
  
</div>
</form>
<div-1>
  <input class = "submitbutton" type="submit" value="Submit">
</div-1>
<div class="gif-bg">
</div>
<style>
  body {
    margin: 100px;
    }
  .gif-bg {
    background:url('') no-repeat center center; 
    min-height:10%;
    min-width:10%;
    Padding: 50px;
    }
   
  .password {
    position:relative;
    font-family: monospace;
    font-size: 15px;
    text-align:center;
    outline:10px black;
    position:absolute;
  }
  .passwordinput {
    border-style: inset;
    border-radius: 4px;
    margin:4px;
    text-align:center;
  }
  .submitbutton {
    border-style: bold;
    border-radius: 4px;
    background-color: #BDD9BF;
    transition-duration: 0.4s;
    margin:4px;
  }
  .submitbutton:hover {
  background-color: grey;
  color: grey;
  }
  </style>
</body>
</html> 
     
     
    