html, body {
  margin: 0;
  padding: 0;
}
html {
  height: 100%;
  box-sizing: border-box;
}
body {
  position: relative;
  padding-bottom: 80px;
  min-height: 100%;
}



#header {
  margin: 0;
  padding: 0;
}



#navigation {
  padding: 16px 0;
  margin: 0;
}



#principal {
  margin: 0 auto;
  max-width: 1400px;
}

#introduction {
  margin: 0 auto;
  padding: 48px 0;
}

#content, #content-sub, #content-extra {
	margin: 0 auto 32px;
	padding: 32px;
}



#footer {
  position: absolute;
  left: 0;
  bottom: 0;
  right: 0;
  padding: 12px;
}