body {
    font-family: sans-serif;
    margin: 0;
    display: flex;
    transition: margin-left 0.3s ease;
}

.sidebar {
    width: 200px;
    height: 100vh;
    background-color: #333;
    padding-top: 20px;
    position: fixed;
    left: 0;
    top: 0;
    transition: width 0.3s ease;
}

.sidebar.collapsed {
    width: 0;
    padding-top: 0;
}

.sidebar ul {
    list-style-type: none;
    padding: 0;
}

.sidebar ul li {
    padding: 15px;
    text-align: center;
}

.sidebar ul li a {
    color: white;
    text-decoration: none;
    display: block;
}

.sidebar ul li a:hover {
    background-color: #555;
}

.content {
    margin-left: 220px;
    padding: 20px;
    width: calc(100% - 220px);
    transition: margin-left 0.3s ease;
}

.sidebar.collapsed + .content {
    margin-left: 0;
    width: 100%;
}

.toggle-btn {
    position: absolute;
    top: 20px;
    left: 200px; /* 初始位置 */
    background: #333;
    color: white;
    border: none;
    padding: 10px;
    font-size: 20px;
    cursor: pointer;
    z-index: 10;
    transition: left 0.3s ease;
}

.welcome-message {
    background-color: #d9a679;
    color: #ffffff;
    font-weight: bold;
    font-size: 1.2em;
    padding: 10px 15px;
    border-radius: 8px;
    text-align: center;
    margin: 10px 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* 當側邊欄收縮時 ，隱藏歡迎訊息 */
.sidebar.collapsed .welcome-message {
    display: none;
}