.spinner {
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top: 2px solid white;
    width: 16px;
    height: 16px;
    animation: spin 1s linear infinite;
}

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

.btn-loading {
    pointer-events: none;
    opacity: 0.7;
}

.btn-loading .spinner {
    display: inline-block !important;
}