SOURCE

<div class="container">
  <div class="center_div">
    <h1>
      Hello World!
    </h1>
    <p>
      This example contains some advanced CSS methods you may not have learned
      yet. But, we will explain these methods in a later chapter in the tutorial.
    </p>
  </div>
</div>

body {
  margin-left: 350px;
  background: #5d9ab2 url('http://www.cvcerie.org/wp-content/themes/cvc2013/img/tree.png') no-repeat top left;
}

.container {
  text-align: center;
}

.center_div {
  
  border: 5px solid gray;
  margin-left: auto;
  margin-right: auto;
  width: 90%;
  background-color: #d0f0f6;
  text-align: left;
  padding: 7px;
}
p{text-indent:50px;}