.particle {
    position: absolute;
    background-color: rgba(0, 210, 255, 0.5);
    border-radius: 50%;
    pointer-events: none;
    animation: floatUp 5s infinite ease-in;
}
@keyframes floatUp {
    0% { transform: translateY(0) scale(1); opacity: 0.8; }
    100% { transform: translateY(-100vh) scale(0); opacity: 0; }
}