/* （前面原本的都保留）... */

/* 新增：切換模式按鈕 */
#toggle-theme {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 0.5rem 1rem;
    border: none;
    background-color: rgba(255, 255, 255, 0.8);
    color: #000;
    font-weight: bold;
    border-radius: 8px;
    cursor: pointer;
    z-index: 1000;
    transition: background 0.3s, color 0.3s;
}

#toggle-theme:hover {
    background-color: rgba(200, 200, 200, 0.9);
}

/* 深色模式 */
.dark-mode {
    background-color: #111; /* 深色背景 */
}

.dark-mode #bg-video {
    opacity: 0.1; /* 背景影片淡掉 */
}

.dark-mode body {
    background-color: #111;
    color: #eee;
}

.dark-mode .card {
    background: rgba(50, 50, 50, 0.85);
}

.dark-mode #toggle-theme {
    background-color: rgba(50, 50, 50, 0.8);
    color: #eee;
}