html, body {
   /* vertikale und horizontale Zentrierung */
   height: 100%;
}
body {
  background-color:#3e3d40; 
  font-family: Arial, sans-serif; 
  font-size: 12px; 
  color: #4b4b4d;
  margin: 0;
}

#rahmen { 
  width: 900px; 
  background-color: white; 
  height: 580px;

  /* ab hier vertikale und horizontale Zentrierung */
  text-align: center;
  position: absolute;
  left: 50%;
  top: 50%; 
  margin-left: -450px; /* Hälfte von Breite */
  margin-top: -280px; /* Hälfte von Höhe */
}

#kopfleiste {
}

#navigation 
   { width: 189px; height: 414px; float: left; 
  text-align: left;
}

#navigation h4 { 
  color: #9c9d9f;
  margin: 10px 0 0 22px;
  font-size: 12px; 
  font-weight: light;
}

#navigation ul { 
   list-style: none;  
   margin-left: 0px;    
   margin-top: 0;
}

#navigation ul li { 
  margin-top: 2px; 
  margin-left: -18px;
  font-weight: light;
}

#navigation ul li a {
   color: #4b4b4d;
   text-decoration: none;
   padding-left: 40px;
   font-size: 12px;
   font-weight: light;
}

#navigation ul li a.active {
   background: transparent url(/images/4.jpg) top left no-repeat;
}

#navigation ul li a:hover {
   color: #000;
}

#inhalt {
   background-color: #fff;
   margin-left: 189px;
   margin-top: -13px;
   text-align: left;
}
#inhalt h3 {
   margin: 0;
}