#loader {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    border: 10px solid gray;
    border-top: 10px solid black;
    margin: 5% auto;
    animation: ease-in-out rotate 2s infinite;
}
@keyframes rotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}