.toast {

    left: 50%; /* 左侧定位到50% */
    transform: translate(-50%, -50%); /* 反向偏移自身宽高的50% */

    position: fixed;
    top: 100px;
    z-index: 1000; /* 确保在顶层 */
    padding: 15px 25px;
    background-color: #4CAF50;
    color: white;
    border-radius: 5px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    opacity: 0;
    transition: opacity 0.3s;
}

.toast.show {
    opacity: 1;
}