body {
background-image: url(Graphics/background.jpg);
 background-repeat: no-repeat;
  background-size: cover;
}

section {
  text-align: center;
  display: block;
  border: 3px solid white;
  border-radius: 5px;
  width: 300px;
  padding: 10px;
  margin: 0 auto;
  background: #B5E2F5;
  background: linear-gradient(0deg, #B5E2F5 0%, #FAD7E9 25%, #FFFFFF 50%, #FAD7E9 75%, #B5E2F5 100%);
}

#blocks{
  width: 100%;
  margin-bottom: 10px;
  }

#blocks2 {
  float: left;
  padding: 0px;
  }
  
marquee > img{
  margin: 5px;
}

header{
  width: 98.4%;

  }
  
header > img{
  width: 80%;
  margin-left: 10%;
  margin-right: 10%;
  }

ul {
  text-align: center;
  list-style-type: none;
  }

#lewy{
  display: block;
  height: 1000px;
  float: left;
}

#prawy{
  display: block;
  height: 1000px;
  float: right;
}

#srodek{
  display: block;
  height: 1000px;
  width: 800px;
}