.loader {
    position: fixed;
    left: calc(50% - 20px);
    border: 6px solid #0087ae; /* light blue */
    border-top: 6px solid #090c5e; /* dark blue */
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 2s linear infinite;
}

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

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