/* 加載動畫 */
.spinner {
    margin: 0 auto;
    width: 40px;
    height: 40px;
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-radius: 50%;
    border-top-color: #3b82f6;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* 隱藏元素的輔助類 */
.hidden {
    display: none !important;
}