html, body {
    height: 100%;
    margin: 0;
}
.center {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.main-content {
    padding-bottom: 96px; /* match station-footer height */
}

#scanInput {
    position: fixed;
    top: 100px;
    left: 100px;
    width: 100px;
    height: 100px;
    opacity: 0;
}