function my_template_redirect(){
if( is_404() && $_SERVER["REQUEST_URI"] != '/404/' ){
header("HTTP/1.0 404 Not Found");
echo "<script type='text/javascript'> document.location.href = 'http://site.ru/404/'; </script>";
exit();
}
}
<div class="white">
</div>
<div class="black">
<span>Simple Text</span>
</div>
.white{
background: white;
}
.black{
background: url(../simplehuinya.png), black;
background-position: top center, 100% 100%;
background-repeat: no-repeat;
background-size: 10%, 100%;
}