#linuxcn_logo_bigl,
#linuxcn_logo_bigl_logo {
    transition: opacity 0.5s ease-in-out;
}

#linuxcn_logo #linuxcn_logo_bigl_logo {
    visibility: hidden;
    opacity: 0;
}

#linuxcn_logo:hover #linuxcn_logo_bigl_logo {
    visibility: visible;
    opacity: 1;
}

#linuxcn_logo #central_point,
#linuxcn_logo #linuxcn_logo_bigl {
    visibility: visible;
    opacity: 1;
}

#linuxcn_logo:hover #central_point,
#linuxcn_logo:hover #linuxcn_logo_bigl {
    visibility: hidden;
    opacity: 0;
}