/* 主导航菜单 */
.main-navigation {
    background: #1a237e;
    padding: 0;
    border-radius: 8px;
}

.main-navigation ul {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.main-navigation > ul > li {
    position: relative;
}

.main-navigation > ul > li > a {
    color: white;
    padding: 15px 20px;
    display: block;
    text-decoration: none;
    font-weight: 600;
    border-right: 1px solid rgba(255,255,255,0.1);
}

.main-navigation > ul > li:last-child > a {
    border-right: none;
}

.main-navigation > ul > li > a:hover {
    background: rgba(255,255,255,0.1);
}

/* 下拉菜单 */
.main-navigation ul ul {
    display: none;
    position: absolute;
    background: white;
    min-width: 200px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    border-radius: 0 0 5px 5px;
    z-index: 1000;
}

.main-navigation ul ul li {
    border-bottom: 1px solid #eee;
}

.main-navigation ul ul li:last-child {
    border-bottom: none;
}

.main-navigation ul ul a {
    color: #333;
    padding: 10px 15px;
    display: block;
}

.main-navigation ul ul a:hover {
    background: #f5f5f5;
}

.main-navigation li:hover > ul {
    display: block;
}

/* 移动端 */
@media (max-width: 768px) {
    .main-navigation ul {
        flex-direction: column;
    }
    
    .main-navigation > ul > li > a {
        border-right: none;
        border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    
    .main-navigation ul ul {
        position: static;
        box-shadow: none;
        background: rgba(0,0,0,0.05);
    }
}