.loader_container {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 99999; /* Sit on top */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgb(0,0,0); /* Fallback color */
    background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
    padding-top: 30%;
}

.loader {
    margin: 0 auto;
    position: relative;
    display: inline-block;
    vertical-align: middle;
    border: 1rem solid #f3f3f3; /* Light grey */
    border-top: 1rem solid #3498db; /* Blue */
    border-radius: 50%;
    width: 5rem;
    height: 5rem;
    animation: spin 2s linear infinite;
    z-index: 999999;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}