#galaxy-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center, #08213a 0%, #031625 100%);
    overflow: hidden;
    z-index: -1;
}

.star {
    position: absolute;
    background: white;
    border-radius: 50%;
    opacity: 0.7;
    animation: moveStar linear infinite;
}

/* movimiento lento */
@keyframes moveStar {
    from { transform: translateY(0); }
    to { transform: translateY(3000px); }
}