body {
    font-family: system-ui, sans-serif;
    color: #000;
  }
  .item {
    background-color: rgb(153, 234, 245);
  }
  .preview {
    height: 100vh; width:100vw;
    z-index: 1;
    opacity: 0.3;
  } 
  .style-fondo{
    background: 
    linear-gradient(to top, rgb(28, 120, 212) 1%, transparent 90%),
    url("images/Noeud-Lacan.png") center center / 40% no-repeat
  }  
.titre {
    height: 15%; width:50%;
    position: absolute;
    top: 0;
    left: 25%;
    text-align: center;
    color: #000;
    font: 40px bold ;
}