canvas {
  display: block;
  vertical-align: bottom;
}

#particles-js {
  position: relative;
  width: 100%;
  height: 100%;
  background-image: url("../img/hero-mob.png");
  background-repeat: no-repeat;
  background-size: cover;
  background-position: 50% 50%;
}

@media (min-width: 768px) {
  #particles-js {
    background-image: url("../img/hero-desk.png");
  }  
}