.fdsdfdsf a {
    display: block;
    padding: 20px 20px;
    transition: all .3s linear;
    position: relative;
    text-decoration: none;
    box-shadow: 0 1px 14px #00000080;
    overflow: hidden;
    width: 100%;
    margin-left: auto;
    margin-right: auto;
    background: #212529;
}

.fdsdfdsf a span:nth-child(1) {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: -moz-linear-gradient(left, rgba(125, 185, 232, 0) 0%, rgba(30, 87, 153, 1) 100%);
    background: -webkit-linear-gradient(left, #7db9e800 0%, #ffe000 100%);
    background: linear-gradient(to right, #7db9e800 0%, #ffe000 100%);
    filter: progid: DXImageTransform.Microsoft.gradient(startColorstr="#007db9e8", endColorstr="#1e5799", GradientType=1);
    animation: animate1 1s linear infinite
}

@keyframes animate1 {
    0% {
        transform: translateX(-100%)
    }
    100% {
        transform: translateX(100%)
    }
}

.fdsdfdsf a span:nth-child(2) {
    position: absolute;
    right: 0;
    top: 0;
    width: 3px;
    height: 100%;
    background: -moz-linear-gradient(top, rgba(125, 185, 232, 0) 0%, rgba(30, 87, 153, 1) 100%);
    background: -webkit-linear-gradient(top, #7db9e800 0%, #ff8100 100%);
    background: linear-gradient(to bottom, #7db9e800 0%, #ff8100 100%);
    filter: progid: DXImageTransform.Microsoft.gradient(startColorstr="#007db9e8", endColorstr="#1e5799", GradientType=0);
    animation: animate2 1s linear infinite .5s
}

@keyframes animate2 {
    0% {
        transform: translateY(-100%)
    }
    100% {
        transform: translateY(100%)
    }
}

.fdsdfdsf a span:nth-child(3) {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: -moz-linear-gradient(left, rgba(30, 87, 153, 1) 0%, rgba(125, 185, 232, 0) 100%);
    background: -webkit-linear-gradient(left, #ff00b1 0%, #00ff6600 100%);
    background: linear-gradient(to right, #ff00b1 0%, #00ff6600 100%);
    filter: progid: DXImageTransform.Microsoft.gradient(startColorstr="#1e5799", endColorstr="#007db9e8", GradientType=1);
    animation: animate3 1s linear infinite
}

@keyframes animate3 {
    0% {
        transform: translateX(100%)
    }
    100% {
        transform: translateX(-100%)
    }
}

.fdsdfdsf a span:nth-child(4) {
    position: absolute;
    left: 0;
    top: 0;
    width: 3px;
    height: 100%;
    background: -moz-linear-gradient(top, rgba(30, 87, 153, 1) 0%, rgba(125, 185, 232, 0) 100%);
    background: -webkit-linear-gradient(top, rgba(30, 87, 153, 1) 0%, rgba(125, 185, 232, 0) 100%);
    background: linear-gradient(to bottom, rgba(30, 87, 153, 1) 0%, rgba(125, 185, 232, 0) 100%);
    filter: progid: DXImageTransform.Microsoft.gradient(startColorstr="#1e5799", endColorstr="#007db9e8", GradientType=0);
    animation: animate4 1s linear infinite .5s
}

@keyframes animate4 {
    0% {
        transform: translateY(100%)
    }
    100% {
        transform: translateY(-100%)
    }
}