Why z-index is not working?

Question

I have this HTML code:

    

        
Title goes here
    

&         


        

Answer 1

I think you have some max height/width, so just write some CSS to #logo

#logo {
    position: absolute;
    z-index: 1;
    width: 100px; /* your maximum in width */
    height: 100px; /* your maximum in height */
    overflow: hidden; /* just to make sure there is nothing leaking your DIV */
}

Answer 2

Just manually set the #right-block position :

#right-block {
    position: relative;
    float: right;
    background-color: blue;
    height: 50px;
    z-index: 5;
}

z-index only woks on absolute|relative|fixed positioned elements, and the default value is for position is static.