.container_n
{
  background-image: url('/sites/chemlek.wum.edu.pl/files/2023-10/closeup-of-a-purple-pipette-refilling-chemistry-gl-2023-03-15-01-21-43-utc-1.jpg');
	background-repeat:no-repeat;
    background-position: top center;
    background-attachment:fixed;
    background-size: cover;

  
  }
  .tlo_b
  {
    background-color: rgba(255, 255, 255, 0.8);
      max-width: 1000px;
      margin: auto;
      padding: 50px; 
  }