* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #fff;
    height: 70px;
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    padding: 0 20px;
}

/* LOGO区域 */
.logo {
    display: flex;
    align-items: center;
}

.logo-text {
    font-size: 24px;
    font-weight: 700;
    color: #2c3e50;
    letter-spacing: 1px;
}

/* 导航菜单 */
.nav-menu {
    display: flex;
    list-style: none;
    height: 100%;
}

.nav-item {
    position: relative;
    height: 100%;
    display: flex;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: #34495e;
    font-size: 16px;
    font-weight: 500;
    padding: 0 20px;
    height: 100%;
    display: flex;
    align-items: center;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #3498db;
    background-color: #f8f9fa;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 20px;
    right: 20px;
    height: 3px;
    background-color: #3498db;
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.nav-link:hover::after {
    transform: scaleX(1);
}

/* 下拉菜单 */
.dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #fff;
    min-width: 220px;
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.15);
    border-radius: 0 0 8px 8px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    z-index: 1001;
}

.nav-item:hover .dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    position: relative;
    padding: 12px 20px;
    border-bottom: 1px solid #f1f1f1;
}

.dropdown-item:last-child {
    border-bottom: none;
}

.dropdown-link {
    display: flex;
    justify-content: space-between;
    align-items: center;
    text-decoration: none;
    color: #34495e;
    font-size: 14px;
    transition: all 0.2s ease;
}

.dropdown-link:hover {
    color: #3498db;
    padding-left: 5px;
}

/* 三级菜单 */
.submenu {
    position: absolute;
    top: 0;
    left: 100%;
    background-color: #fff;
    min-width: 200px;
    box-shadow: 5px 5px 15px rgba(0, 0, 0, 0.1);
    border-radius: 0 8px 8px 8px;
    opacity: 0;
    visibility: hidden;
    transform: translateX(10px);
    transition: all 0.3s ease;
}

.dropdown-item:hover .submenu {
    opacity: 1;
    visibility: visible;
    transform: translateX(0);
}

.submenu-item {
    padding: 12px 20px;
    border-bottom: 1px solid #f1f1f1;
}

.submenu-item:last-child {
    border-bottom: none;
}

.submenu-link {
    text-decoration: none;
    color: #34495e;
    font-size: 14px;
    transition: all 0.2s ease;
}

.submenu-link:hover {
    color: #3498db;
    padding-left: 5px;
}

/* 移动端菜单切换 */
.mobile-toggle {
    display: none;
    font-size: 24px;
    cursor: pointer;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: #fff;
        flex-direction: column;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .nav-item {
        height: auto;
        width: 100%;
    }
    
    .nav-link {
        padding: 15px 20px;
        width: 100%;
    }
    
    .dropdown {
        position: static;
        width: 100%;
        box-shadow: none;
        border-radius: 0;
        transform: none;
        opacity: 1;
        visibility: visible;
        display: none;
        background-color: #f8f9fa;
    }
    
    .nav-item:hover .dropdown {
        transform: none;
    }
    
    .dropdown.active {
        display: block;
    }
    
    .submenu {
        position: static;
        width: 100%;
        box-shadow: none;
        border-radius: 0;
        transform: none;
        opacity: 1;
        visibility: visible;
        display: none;
        background-color: #f1f1f1;
    }
    
    .dropdown-item:hover .submenu {
        transform: none;
    }
    
    .submenu.active {
        display: block;
    }
    
    .mobile-toggle {
        display: block;
    }
}

@media (max-width: 576px) {
    .logo-text {
        font-size: 20px;
    }
}