.background-container {
position: fixed;
top: 0;
left: 0;
height: 100vh;
width: 100vw;
background: url(https://i.ibb.co/GCcS8Zw/Abstract-futuristic-Molecules-technology-with-polygonal-shapes-on-dark-blue-background-Illustration.jpg);
background-size: cover;
clip-path: unset;
Funziona perfettamente, grazie!