#can {
    filter: brightness(100%);
}

#cannot {
    filter: brightness(25%);
}

#can1 {
    z-index: -99;
}


#cannot1 {
    z-index: 99;
}

#techtree td {
    width: 40px;
    height: 40px;
}

#techtree img {
    position: relative;
    top: 2px;
}


li {
    line-height: 1.8
}