index.html

<!DOCTYPE html>
<html lang="ja">
<head>
<meta charset="UTF-8">
<title>Git Playground!!</title>
<meta name="keywords" content="">
<meta name="description" content="">
<script src="js/jquery-1.11.2.min.js"></script>
<script>
  $(function(){
    $('button').click(function(){
      alert('おっす！');
    });
  });
</script>
</head>
<body>
<style>
*{
  margin:0;
  padding: 0;
  box-sizing: border-box;
}
.box{
  position:absolute;
  top:50%;
  left:50%;
  transform: translate(-50%, -50%);
  width: 500px;
  height: 500px;
  background-color: #000;
  border:4px solid #D10000;
}
p{
  font-size: 50px;
  line-height: 500px;
  text-align: center;
  color: #fff;
}
</style>
<button>いいね！</button>
<div class="box">
  <p>上野毛道場へ行こう</p>
</div>
</body>
</html>