gistfile1.txt

SASS:

%plane
    box-shadow: 0 2px 5px rgba(#000, .1)
    border-radius: 5px

%white-plane
    @extend %plane
    background-color: #fff

%off-white-plane
    @extend %plane
    background-color: #fcfcfc


header
    @extend %white-plane

footer
    @extend %off-white-plane


CSS:

header, footer {
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  border-radius: 5px; }

header {
  background-color: white; }

footer {
  background-color: #fcfcfc; }