body {
    text-align: center;
}
.logo-loader {
    position: absolute;
    top: 50%;
    left: 50%;
    margin: -2.5em 0 0 -2.5em;
    font-size: 31px;
    width: 1em;
    height: 1em;
    background-color: #fff;
    filter: contrast(20);
    border: 2em solid #fff;
}
    .logo-loader i {
        position: absolute;
        width: 0;
        height: 0;
        font-size: 1em;
    }
        .logo-loader i:after {
            content: '';
            display: block;
            border-radius: 50%;
            background-color: #000;
            transform: translate(-50%, -50%);
            animation: pulsate .4s linear infinite alternate;
            filter: blur(.15em);
        }
    .logo-loader i:nth-child(1) {
        top: 0;
        left: 0;
    }
        .logo-loader i:nth-child(1)::after {
            width: .87em;
            height: .87em;
        }
    .logo-loader i:nth-child(2) {
        top: 0;
        right: 0;
    }
        .logo-loader i:nth-child(2)::after {
            width: .678em;
            height: .678em;
            animation-delay: -.1s;
        }
    .logo-loader i:nth-child(3) {
        bottom: 0;
        left: 0;
    }
        .logo-loader i:nth-child(3)::after {
            width: .516em;
            height: .516em;
            animation-delay: -.2s;
        }
    .logo-loader i:nth-child(4) {
        bottom: 0;
        right: 0;
    }
        .logo-loader i:nth-child(4)::after {
            width: 1.065em;
            height: 1.065em;
            animation-delay: -.3s;
        }
@keyframes pulsate {
    from {
        transform: translate(-50%, -50%) scale(0.8);
    }
    to {
        transform: translate(-50%, -50%) scale(1.3);
    }
}