#nav {
    width: 72px !important;
    transition: width 0.3s ease !important;
}

#nav.active {
    width: 200px !important;
    transition: width 0.3s ease !important;
}

#contents {
    width: calc(100% - 72px) !important;
    transition: width 0.3s ease !important;
}

#nav.active~#contents {
    width: calc(100% - 200px) !important;
    transition: width 0.3s ease !important;
}