37 div.yubikey_bar {

    38   width: 88px;

    39   height: 88px;

    40   margin: 4px auto;

    41   text-align: center;

    42   background-image: url(./field.png);

    43   background-repeat: no-repeat;

    44 }

    45 

    46 div.yubikey_bar > img {

    47   width: 0px;

    48   height: 88px;

    49   background-image: url(./field.png);

    50   background-repeat: no-repeat;

    51   background-position: -44px -88px;

    52 }

    53 

    54 div.yubikey_bar > img.yubikey_bar_error {

    55   width: 88px !important;

    56   background-position: 0px -176px !important;

    57 }