title: Why is this div not centered?
body: <p><a href="https://codepen.io/cavad/pen/wvoOJdL?editors=1100" rel="nofollow noreferrer">https://codepen.io/cavad/pen/wvoOJdL?editors=1100</a></p>
  <p>I hate css.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code> 
  
  *{
      margin:0px;
      padding: 0px;
  }
  .sekil1{
      position: relative;
      top:40px;
      left: 10px;
      width: 400px;
      height: 400px;
      background-color: grey; 
  }
  .sekil1 img{
      margin: 5px;
      max-width: calc(100% - 10px);
      height: auto;
      max-height:calc(100% - 10px);
  } 
  .sekiller img{
      margin:10px 10px;
      width: 100px;
      height:100px;
      float: left;
  }
  .sekiller{
      position: absolute;
      top: 40px;
      left: 410px;
      width: 500px;
      height: 400px;
      background: grey;
  }
  .elanbasligi{
      position: absolute;
      top:10px;
      left: 10px;
      font-size: 20px;
  }
  .haqqinda{
      font-size: 20px;
      position: relative;
      top: 40px;
      margin-left: 10px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code> this is html 
  
  &lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
      &lt;meta charset='utf-8'&gt;
      &lt;link rel="stylesheet" type="text/css" href="ferhadsatilir.css"&gt;
      
  &lt;/head&gt;
  &lt;body&gt;
  &lt;div class='butunsekiller'&gt;
  
  &lt;div class='sekil1'&gt;&lt;img src=https://upload.wikimedia.org/wikipedia/commons/thumb/6/62/1969_Dodge_Charger_%2821572136732%29.jpg/1280px-1969_Dodge_Charger_%2821572136732%29.jpg&gt;&lt;/div&gt; &lt;br&gt;
  
  &lt;div class='sekiller'&gt;
  &lt;div class='sekil2'&gt;&lt;img src=https://upload.wikimedia.org/wikipedia/commons/thumb/6/62/1969_Dodge_Charger_%2821572136732%29.jpg/1280px-1969_Dodge_Charger_%2821572136732%29.jpg&gt;&lt;/div&gt; 
  
  &lt;div class='sekil3'&gt;&lt;img src=https://upload.wikimedia.org/wikipedia/commons/thumb/6/62/1969_Dodge_Charger_%2821572136732%29.jpg/1280px-1969_Dodge_Charger_%2821572136732%29.jpg&gt;&lt;/div&gt; 
  
  
  &lt;div class='sekil4'&gt;&lt;img src=https://upload.wikimedia.org/wikipedia/commons/thumb/6/62/1969_Dodge_Charger_%2821572136732%29.jpg/1280px-1969_Dodge_Charger_%2821572136732%29.jpg&gt;&lt;/div&gt; 
  &lt;/div&gt;
  &lt;/div&gt;
  &lt;div class='elanbasligi'&gt;&lt;h3&gt;Ferhad satilir&lt;/h3&gt;&lt;/div&gt; &lt;br&gt; 
  &lt;div class='haqqinda'&gt;
  &lt;div class='qiymet'&gt;qiymet :22AZN&lt;/div&gt; &lt;br&gt;
  &lt;div class='seher'&gt;seher : baki&lt;/div&gt; &lt;br&gt;
  &lt;div class='katagoriya'&gt;katagoriya :bir sey&lt;/div&gt; &lt;br&gt;
  &lt;div class='nomre'&gt;elaqe nomresi : 066236487623864&lt;/div&gt; &lt;br&gt;
  &lt;div class='elanhaqqinda'&gt;elanhaqqinda : yazilar&lt;/div&gt; &lt;br&gt;
  &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;</code></pre>
  </div>
  </div>
  </p>