body {
  margin: 0px;
}

#baner {
  background-color: lightskyblue;
  padding: 20px;
}

#lewy {
  background-color: lightgray;
  height: 600px;
  width: 25%;
  float: left;
}

#prawy {
  background-color: white;
  height: 600px;
  width: 75%;
  float: left;
}

#stopka {
  background-color: lightskyblue;
  clear: both;
  padding: 20px;
}