Try to use the overflow: hidden;
property at the element that you want to put in front of the particles.js;
#main-section {
overflow: hidden;
}
#particles-js {
position: absolute;
width: 100%;
height: 100%;
background-repeat: no-repeat;
background-size: cover;
background-position: 50% 50%;
opacity: 0.48;
}