/* CSS for the loading spinner */
.button-loader {
    position: relative;
    overflow: hidden;
}

.button-loader:after {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    width: 24px;
    height: 24px;
    margin: -12px 0 0 -12px;
    border: 4px solid #fff;
    border-top: 4px solid #3498db;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    box-sizing: border-box;
    transform-origin: 50% 50%;
}

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