.background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url("../assets/background-circuit.png");
    background-size: cover;
    opacity: 0.18;
    animation: pulse 6s infinite ease-in-out;
    z-index: -1;
}

@keyframes pulse {
    0% { opacity: 0.15; }
    50% { opacity: 0.25; }
    100% { opacity: 0.15; }
}