custom.css

body, html {
    height: 100%; 
    background-image: url("bg.jpg");
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}                    
#loading {
    height: 100%;
    left: 0;
    margin: auto;
    position: fixed;
    top: 0;
    width: 100%;
}
.bokeh {
    border: 0.01em solid rgba(150, 150, 150, 0.1);
    border-radius: 50%;
    font-size: 100px;
    height: 1em;
    list-style: outside none none;
    margin: 0 auto;
    position: relative;
    top: 35%;
    width: 1em;
    z-index: 2147483647;
}
.bokeh li {
    border-radius: 50%;
    height: 0.2em;
    position: absolute;
    width: 0.2em;
}
.bokeh li:nth-child(1) {
    animation: 1.13s linear 0s normal none infinite running rota, 3.67s ease-in-out 0s alternate none infinite running opa;
    background: #00c176 none repeat scroll 0 0;
    left: 50%;
    margin: 0 0 0 -0.1em;
    top: 0;
    transform-origin: 50% 250% 0;
}
.bokeh li:nth-child(2) {
    animation: 1.86s linear 0s normal none infinite running rota, 4.29s ease-in-out 0s alternate none infinite running opa;
    background: #ff003c none repeat scroll 0 0;
    margin: -0.1em 0 0;
    right: 0;
    top: 50%;
    transform-origin: -150% 50% 0;
}
.bokeh li:nth-child(3) {
    animation: 1.45s linear 0s normal none infinite running rota, 5.12s ease-in-out 0s alternate none infinite running opa;
    background: #fabe28 none repeat scroll 0 0;
    bottom: 0;
    left: 50%;
    margin: 0 0 0 -0.1em;
    transform-origin: 50% -150% 0;
}
.bokeh li:nth-child(4) {
    animation: 1.72s linear 0s normal none infinite running rota, 5.25s ease-in-out 0s alternate none infinite running opa;
    background: #88c100 none repeat scroll 0 0;
    margin: -0.1em 0 0;
    top: 50%;
    transform-origin: 250% 50% 0;
}
@keyframes opa {
12% {
    opacity: 0.8;
}
19.5% {
    opacity: 0.88;
}
37.2% {
    opacity: 0.64;
}
40.5% {
    opacity: 0.52;
}
52.7% {
    opacity: 0.69;
}
60.2% {
    opacity: 0.6;
}
66.6% {
    opacity: 0.52;
}
70% {
    opacity: 0.63;
}
79.9% {
    opacity: 0.6;
}
84.2% {
    opacity: 0.75;
}
91% {
    opacity: 0.87;
}
}

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