html, body {
  margin: 0; /* This can vary from browser to browser, so explicitly set it. */
  padding: 0; /* This can vary from browser to browser, so explicitly set it. */
}

body {
  padding: 0 1em;
}

ul#nav a {
  text-decoration: none;
  color: grey;
}

ul#nav a:hover {
  font-weight: bold;
}

body#home ul#nav a#a_home {
  color: black;
  font-weight: normal;
}

body#slideShow ul#nav a#a_slideShow {
  color: black;
  font-weight: normal;  
}

body#contact ul#nav a#a_contact {
  color: black;
  font-weight: normal;  
}