CSS
body {
background: #2196F3;
}
.wrapper {
position: absolute;
top: 50%;
left: 50%;
width: 304px;
height: 30px;
border: 4px #fff solid;
margin: -15px 0 0 -152px;
box-shadow: inset 0 2px 6px rgba(0,0,0,0.5);
overflow: hidden;
}
.loader {
position: relative;
display: inline-block;
background: #fff;
opacity: 0;
width: 20px;
height: 20px;
margin: 5px;
box-shadow: 2px 4px 6px rgba(0,0,0,0.5);
animation: opacity 6s infinite;
}
.loader:nth-child(1) { animation-delay: 0.3s; }
.loader:nth-child(2) { animation-delay: 0.6s; }
.loader:nth-child(3) { animation-delay: 0.9s; }
.loader:nth-child(4) { animation-delay: 1.2s; }
.loader:nth-child(5) { animation-delay: 1.5s; }
.loader:nth-child(6) { animation-delay: 1.8s; }
.loader:nth-child(7) { animation-delay: 2.1s; }
.loader:nth-child(8) { animation-delay: 2.4s; }
.loader:nth-child(9) { animation-delay: 2.7s; }
@keyframes opacity {
0% {
opacity: 0;
}
5% {
opacity: 1;
}
50% {
opacity: 1;
}
100% {
opacity: 0;
}
}
