Question

See the Sign Up login on http://colrd.com/ when you scroll.

Answer 1

They simply add class “scroll” to div container “introduction” which change css properties.

#introduction.scroll {
position: fixed;
top: 45px;
width: 100%;
z-index: 1000;
border-radius: 0;
-moz-border-radius: 0;
-webkit-border-radius: 0;
font-size: inherit;
font-weight: bold;
border-bottom: 1px solid white;
box-shadow: 0px 1px 5px black;
-moz-box-shadow: 0px 1px 5px #000;
-webkit-box-shadow: 0px 1px 5px black;
border-bottom-color: rgba(255, 255, 255, .5);
min-width: 1054px;
}