.loader{
position: relative;
width: 8em;
height: 8em;
margin: 20px auto;
overflow: hidden;
background: rgba(0, 0, 0, 0.35);
}
.loader > div {
position: absolute;
width: 8em;
height: 8em;
animation: alpha 2.25s linear infinite forwards;
background: rgba(231, 76, 60, 0.75);
}
.loader > div:nth-child(1) {
top: -50%;
left: -50%;
}
.loader > div:nth-child(2) {
top: -50%;
right: -50%;
}
.loader > div:nth-child(3) {
bottom: -50%;
right: -50%;
}
.loader > div:nth-child(4) {
bottom: -50%;
left: -50%;
}
@keyframes alpha {
0% {
-moz-transform: rotate(0);
-ms-transform: rotate(0);
-webkit-transform: rotate(0);
transform: rotate(0);