@-webkit-keyframes spin-rotate
{
    0%
    {
        -webkit-transform: rotate(0deg);
                transform: rotate(0deg);
    }
    50%
    {
        -webkit-transform: rotate(-180deg);
                transform: rotate(-180deg);
    }
    100%
    {
        -webkit-transform: rotate(-360deg);
                transform: rotate(-360deg);
    }
}

@-moz-keyframes spin-rotate
{
    0%
    {
        -moz-transform: rotate(0deg);
             transform: rotate(0deg);
    }
    50%
    {
        -moz-transform: rotate(-180deg);
             transform: rotate(-180deg);
    }
    100%
    {
        -moz-transform: rotate(-360deg);
             transform: rotate(-360deg);
    }
}

@-o-keyframes spin-rotate
{
    0%
    {
        -o-transform: rotate(0deg);
           transform: rotate(0deg);
    }
    50%
    {
        -o-transform: rotate(-180deg);
           transform: rotate(-180deg);
    }
    100%
    {
        -o-transform: rotate(-360deg);
           transform: rotate(-360deg);
    }
}

@keyframes spin-rotate
{
    0%
    {
        -webkit-transform: rotate(0deg);
           -moz-transform: rotate(0deg);
             -o-transform: rotate(0deg);
                transform: rotate(0deg);
    }
    50%
    {
        -webkit-transform: rotate(-180deg);
           -moz-transform: rotate(-180deg);
             -o-transform: rotate(-180deg);
                transform: rotate(-180deg);
    }
    100%
    {
        -webkit-transform: rotate(-360deg);
           -moz-transform: rotate(-360deg);
             -o-transform: rotate(-360deg);
                transform: rotate(-360deg);
    }
}

.semi-circle-spin
{
    position: relative;

    overflow: hidden; 

    width: 35px;
    height: 35px;
}
.semi-circle-spin > div
{
    position: absolute;

    width: 100%;
    height: 100%; 

    -webkit-animation: spin-rotate .6s 0s infinite linear;
       -moz-animation: spin-rotate .6s 0s infinite linear;
         -o-animation: spin-rotate .6s 0s infinite linear;
            animation: spin-rotate .6s 0s infinite linear;

    border-width: 0;
    border-radius: 100%;
    background-image: -webkit-gradient(linear, right top, right bottom, from(transparent), color-stop(70%, transparent), color-stop(30%, #55595c), to(#55595c));
    background-image: -webkit-linear-gradient(transparent 0%, transparent 70%, #55595c 30%, #55595c 100%);
    background-image:    -moz-linear-gradient(transparent 0%, transparent 70%, #55595c 30%, #55595c 100%);
    background-image:      -o-linear-gradient(transparent 0%, transparent 70%, #55595c 30%, #55595c 100%);
    background-image: -webkit-gradient(linear, left top, left bottom, from(transparent), color-stop(70%, transparent), color-stop(30%, #55595c), to(#55595c));
    background-image:         linear-gradient(transparent 0%, transparent 70%, #55595c 30%, #55595c 100%);
}