.loading {
    position: relative;
}

.loading::after {
    content: "";
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-left-color: #fff;
    border-radius: 50%;
    width: 10px;
    height: 10px;
    margin-left: 10px;
    display: inline-block;
    animation: spin 1s linear infinite;
    vertical-align: middle;
}

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