body {
  font: 100% sans-serif;
  background: darkgreen;
  background-attachment: fixed;
  color: black;
  margin: 0px;  
}
.kopf {
  color: black;
  background-color: springgreen;
}
<!--position: fixed; -->
.container {
  width: 390px; 
  margin: 0px auto; margin-top: 0px;
  background-color: white;
  background: white;
  
  background-attachment: fixed;
 
}
.fuss {
  background-color: springgreen; color: black;
  
  padding: 12px;
  font-weight: normal;
 
 
}
.inhalt, .kopf {
  padding: 0px;
}
.inhalt h1 {
  text-align: left;
  color: black;
  
}

.inhalt h3 {
  color: black;
}
.inhalt {
  margin-left: 10px; margin-right: 10px; padding-top: 100px;
}
h1 {
  letter-spacing: -1px;
}
.navigation {
  font-weight: bold;
  letter-spacing: 2px;
  
  background-color: springgreen;
  color: black;
  overflow: hidden;
}
.navigation ul {
  list-style-type: none;
  margin: 0;
  padding: 0px 0px 0px 10px;
}
.navigation li {
  margin: 0;
  padding: 0;
  float: left;
}
.navigation a {
  color: black;
  display: block;
  text-decoration: none;
  padding: 12px;
}
.navigation a:hover, .navigation a:active, .navigation a:focus .navigation a:visited {
  background-color: cyan; color: darkblue;
  
}
.navigation a {
  
  border-top-left-radius: 14px;
  border-top-right-radius: 14px;
  border-bottom-left-radius: 14px;
  border-bottom-right-radius: 14px;
}

<!-- background: webkit-linear-gradient(red 20%, red 24%, orange 24%, orange 28%, yellow 28%, yellow 32%, green 32%, green 36%, blue 36%, blue 40% black 40%); -->