#loader {
    border: 12px solid #f3f3f3;
    border-radius: 50%;
    border-top: 20px solid #1e90ff;
    border-right: 20px solid white;
    border-bottom: 20px solid #1e90ff;
    border-left: 20px solid white;
    width: 100px;
    height: 100px;
    animation: spin 0.5s linear infinite;
}

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

.center {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    margin: auto;
}