#invoiceSpinner{
 position:fixed;
 inset:0;
 background:rgba(255,255,255,0.7);
 display:none;
 z-index:200000;
}

.spinner {
 position:absolute;
 top:50%;
 left:50%;
 transform:translate(-50%,-50%);
 border:6px solid #f3f3f3;
 border-top:6px solid #3498db;
 border-radius:50%;
 width:50px;
 height:50px;
 animation:spin 1s linear infinite;
}

@keyframes spin{
 0%{transform:translate(-50%,-50%) rotate(0deg)}
 100%{transform:translate(-50%,-50%) rotate(360deg)}
}