body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
    color: #333;
}

header {
    background-color: #333;
    color: #fff;
    padding: 1rem 0;
    text-align: center;
}

nav ul {
    list-style: none;
    padding: 0;
}

nav ul li {
    display: inline;
    margin: 0 10px;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
}

main {
    padding: 20px;
    max-width: 960px;
    margin: 20px auto;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

footer {
    text-align: center;
    padding: 1rem 0;
    margin-top: 20px;
    background-color: #333;
    color: #fff;
}

/* 可收合選單樣式 */
.sidebar-nav > ul > li {
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

.sidebar-dropdown > a {
    position: relative;
    cursor: pointer;
}

.sidebar-dropdown > a::after {
    content: '▶';
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 10px;
    transition: transform 0.2s ease;
    opacity: 0.7;
}

.sidebar-submenu {
    display: none;
    list-style: none;
    padding: 0;
    margin: 0;
    background-color: rgba(0,0,0,0.15);
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.sidebar-submenu li a {
    padding: 8px 16px 8px 35px !important;
    font-size: 12px !important;
    border-left: 3px solid transparent;
    transition: all 0.2s ease;
}

.sidebar-submenu li a:hover {
    background-color: rgba(52, 152, 219, 0.3) !important;
    border-left-color: #3498db;
}

.sidebar-dropdown.open > a {
    background-color: rgba(52, 152, 219, 0.2);
}

.sidebar-dropdown.open > a::after {
    transform: translateY(-50%) rotate(90deg);
}

.sidebar-dropdown.open .sidebar-submenu {
    display: block;
}

/* 選單圖標樣式 */
.menu-icon {
    margin-right: 10px;
    font-style: normal;
    font-size: 14px;
}

/* 側邊欄底部連結 */
.sidebar-footer-links {
    display: flex;
    justify-content: space-around;
    padding: 15px 10px;
    border-top: 1px solid rgba(255,255,255,0.1);
    margin-top: 10px;
    background-color: rgba(0,0,0,0.1);
}

.sidebar-footer-links a {
    color: #ecf0f1;
    text-decoration: none;
    font-size: 13px;
    padding: 8px 15px;
    border-radius: 5px;
    transition: background-color 0.2s ease;
}

.sidebar-footer-links a:hover {
    background-color: rgba(255,255,255,0.1);
}

.sidebar-footer-links .logout-link:hover {
    background-color: rgba(231, 76, 60, 0.3);
}