CSS Sticky header

I have added a sticky header to my homepage, however the sticky header seems to be behind the rest of the content on the page, so when i scroll down the page, images and text are on top of the header, is there a way to stop this?

Here is my code:

<style>
/* Reset body padding and margins */
body
{
    margin: 0;
    padding: 0;
}

/* Make Header Sticky */
#header_container
{
    background: #827878;
    border: 1px solid #666;
    height: 60px;
    left: 0;
    position: fixed;
    width: 100%;
    top: 0;
}

#header
{
    line-height: 60px;
    margin: 10 auto;
    width: 940px;
    text-align: left;
    font-size: 26px;
    color: #f5f5f5;
    line-height: 28px;
    margin-bottom: 14px;
    font-family: 'Source Sans Pro',sans-serif;
}

/* CSS for the content of page. I am giving top and bottom 
   padding of 80px to make sure the header and footer 
   do not overlap the content. */
#container
{
    margin: 0 auto;
    overflow: auto;
    padding: 80px 0;
    width: 940px;
}

#content
{
}

/* Make Footer Sticky */
#footer_container
{
    background: #eee;
    border: 1px solid #666;
    bottom: 0;
    height: 60px;
    left: 0;
    position: fixed;
    width: 100%;
}

#footer
{
    line-height: 60px;
    margin: 0 auto;
    width: 940px;
    text-align: center;
}
</style>


<!-- BEGIN: Sticky Header -->
<div id="header_container">
    <div id="header">
        Header Content
    </div>
</div>
<!-- END: Sticky Header -->

Add this code: Add z-index: 1000 in both #header_container & z-index: 1001 in #header styles.

#header_container { 
    position: fixed;
    top: 0px;
    left: 0px;
    z-index: 1000;
}

#header {
    z-index: 1001;
}