html,
body {
    height: 100%;
    background-color: black;
}


@-moz-keyframes heartbeat-loader {
    0% {
        -moz-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }

    14% {
        -moz-transform: rotate(45deg) scale(1.3);
        transform: rotate(45deg) scale(1.3);
    }

    28% {
        -moz-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }

    42% {
        -moz-transform: rotate(45deg) scale(1.3);
        transform: rotate(45deg) scale(1.3);
    }

    70% {
        -moz-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }
}

@-webkit-keyframes heartbeat-loader {
    0% {
        -webkit-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }

    14% {
        -webkit-transform: rotate(45deg) scale(1.3);
        transform: rotate(45deg) scale(1.3);
    }

    28% {
        -webkit-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }

    42% {
        -webkit-transform: rotate(45deg) scale(1.3);
        transform: rotate(45deg) scale(1.3);
    }

    70% {
        -webkit-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }
}

@keyframes heartbeat-loader {
    0% {
        -moz-transform: rotate(45deg) scale(1);
        -ms-transform: rotate(45deg) scale(1);
        -webkit-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }

    14% {
        -moz-transform: rotate(45deg) scale(1.3);
        -ms-transform: rotate(45deg) scale(1.3);
        -webkit-transform: rotate(45deg) scale(1.3);
        transform: rotate(45deg) scale(1.3);
    }

    28% {
        -moz-transform: rotate(45deg) scale(1);
        -ms-transform: rotate(45deg) scale(1);
        -webkit-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }

    42% {
        -moz-transform: rotate(45deg) scale(1.3);
        -ms-transform: rotate(45deg) scale(1.3);
        -webkit-transform: rotate(45deg) scale(1.3);
        transform: rotate(45deg) scale(1.3);
    }

    70% {
        -moz-transform: rotate(45deg) scale(1);
        -ms-transform: rotate(45deg) scale(1);
        -webkit-transform: rotate(45deg) scale(1);
        transform: rotate(45deg) scale(1);
    }
}
/* :not(:required) hides this rule from IE9 and below */
.heartbeat-loader:not(:required) {
    top: 50%;
    left: 50%;
    margin-top: -25px;
    margin-left: -15px;
    position: absolute;
    -moz-animation: heartbeat-loader 1300ms ease 0s infinite normal;
    -webkit-animation: heartbeat-loader 1300ms ease 0s infinite normal;
    animation: heartbeat-loader 1300ms ease 0s infinite normal;
    display: inline-block;
    /*position: relative;*/
    overflow: hidden;
    text-indent: -9999px;
    width: 36px;
    height: 36px;
    -moz-transform: rotate(45deg) scale(1);
    -ms-transform: rotate(45deg) scale(1);
    -webkit-transform: rotate(45deg) scale(1);
    transform: rotate(45deg) scale(1);
    -moz-transform-origin: 50% 50%;
    -ms-transform-origin: 50% 50%;
    -webkit-transform-origin: 50% 50%;
    transform-origin: 50% 50%;
}

    .heartbeat-loader:not(:required):after, .heartbeat-loader:not(:required):before {
        position: absolute;
        content: "";
        background: #e87;
    }

    .heartbeat-loader:not(:required):before {
        -moz-border-radius-topleft: 12px;
        -webkit-border-top-left-radius: 12px;
        border-top-left-radius: 12px;
        -moz-border-radius-bottomleft: 12px;
        -webkit-border-bottom-left-radius: 12px;
        border-bottom-left-radius: 12px;
        top: 12px;
        left: 0;
        width: 36px;
        height: 24px;
    }

    .heartbeat-loader:not(:required):after {
        -moz-border-radius-topleft: 12px;
        -webkit-border-top-left-radius: 12px;
        border-top-left-radius: 12px;
        -moz-border-radius-topright: 12px;
        -webkit-border-top-right-radius: 12px;
        border-top-right-radius: 12px;
        top: 0;
        left: 12px;
        width: 24px;
        height: 12px;
    }