/* Trạng thái loading cho button */
button.is-loading,
input[type="submit"].is-loading {
    position: relative;
    pointer-events: none;
    opacity: 0.7;
}

/* Tạo vòng xoay */
button.is-loading::after,
input[type="submit"].is-loading::after {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    width: 16px;
    height: 16px;
    margin-top: -8px;
    margin-left: -8px;
    border: 2px solid #fff;
    border-top-color: transparent;
    border-radius: 50%;
    animation: yeekit-spin 0.6s linear infinite;
}

/* Animation */
@keyframes yeekit-spin {
    0%   { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}