html,
body {
    margin: 0;
}

.loading {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 24px;
    height: 24px;
    transform: translate(-50%, -50%);
}

.loading>div {
    border: 3px solid #f3f3f3;
    border-top: 3px solid #3498db;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    animation: spin 1.2s linear infinite;
}

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

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