#wrapper:empty {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

#wrapper:empty:before {
    content: '';
    display: inline-block;
    width: 26px;
    height: 26px;
    border: 2px solid #eee;
    border-left-color: #aaa;
    border-radius: 50%;
    -moz-animation: loading 0.9s infinite linear;
    -webkit-animation: loading 0.9s infinite linear;
    animation: loading 0.9s infinite linear;
}