ui-loading {
    display: block;
    position: relative;
    margin: 5px auto;
    width: 30px;
    height: 30px;
    div {
        position: absolute;
        left: 0;
        top: 0;
        width: 100%;
        height: 100%;
        span {
            display: block;
            margin: 5% auto;
            width: 2px;
            border-radius: 2px;
            height: 25%;
            background-color: #999;
            animation: loading-animation 1.2s infinite ease-in-out both;
        }
    }
    @for $i from 1 through 12 {
        .ui-circle-#{$i} {
            transform: rotate(#{$i * 30}deg);
            span {
                animation-delay: #{-1.2 + $i / 10}s;
            }
        }
    }
}

@keyframes loading-animation {
    0%,
    39%,
    100% {
        opacity: .3;
    }
    40% {
        opacity: 1;
    }
}