Shadow not showing up

I am trying to place shadows in one of the div and it's not showing up. Here is one div where I am trying to implement the shadow:

#intro {
    padding: 0px;
    margin: 0px auto;
    width: 100%;
    float:inherit;
    overflow: hidden;
    height: 800px;
    position:inherit;
    background-color: #00b3e1;; 
    box-shadow: 0 0 50px rgba(0,0,0,0.8);
}