CSS image opacity only
<p>I have a page at <a href="http://shivampaw.ml/blog" rel="nofollow">http://shivampaw.ml/blog</a></p>

<p>It has a header image and is using Wordpress. I am trying to make the header image slightly less opaque and set it to opacity: 0.6</p>

<p>However when I use:</p>

<pre><code>site-header{
     opacity: 0.6;
}
</code></pre>

<p>It makes the entire div less opaque. I have researched and I don't think I can change the divs as they are using Wordpress.</p>

<p>How can I achieve this?</p>

<p>Is it also possible to make the background image fixed? Right now it repeats which means it has a weird colour change. I want to avoid that so can I make it fixed? I tried changing background-attachment but that didn't work.</p>