title: how do i blur background behind the text
body: <p>Can anyone help me find what's the mistake in doing here? I am trying to bring the text above the background but if i used <code>z-index: -1;</code> it will disappear or just go to the back and won't be able to see it. and also wont mind to say if there's a better way to reform all the that code.</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>html, body {margin:0;padding:0}
  
  .page-title {
    position: absolute;
    max-width: 38%;
    top: 50px;
    left: 0;
  }
  
  .hero-title {
    background: rgba(0,0,0,.4);
    padding: 15px 15px 15px 40px;
  }
  
  .hero-title::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    z-index: 1;
    background: rgba(0, 0, 0, 0.5);
    width: 100%;
    height: 100%;
    -webkit-filter: blur(5px);
    -moz-filter: blur(5px);
    -o-filter: blur(5px);
    -ms-filter: blur(5px);
    filter: blur(5px);
  }
  
  .text-wraper {
    z-index: 700;
    color: #fff;
    width: 100%;
  }
  
  .main-title {
    font-size: 36px;
    font-weight: 700;
    letter-spacing: -1pt;
    line-height: 1em;
    text-transform: uppercase;
  }
  
  .sub-title {
    font-size: 24px;
    font-weight: 300;
    line-height: 1em;
    text-transform: uppercase;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="hero-image"&gt;
    &lt;span class="deskTop1280"&gt;
      &lt;img src="http://via.placeholder.com/1280x500/246D5F" width="100%" alt=""&gt;
    &lt;/span&gt;
  &lt;/div&gt;
  &lt;div class="page-title"&gt;
    &lt;div class="hero-title"&gt;
      &lt;div class="text-wraper"&gt;
        &lt;div class="main-title"&gt;Main title goes here&lt;/div&gt;
        &lt;div class="sub-title"&gt;sub title goes here&lt;/div&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>