/* 导航样式 */
 .nav-container {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    padding: 0 20px;
    margin-bottom: 30px;
}

.nav-menu {
    display: flex;
    list-style: none;
    justify-content: center;
    position: relative;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: block;
    padding: 18px 25px;
    color: #555;
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
    border-bottom: 2px solid transparent;
}

.nav-link:hover {
    color: #3498db;
    border-bottom: 2px solid #3498db;
}

/* 分隔线 */
.nav-item:not(:last-child)::after {
    content: "";
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    height: 16px;
    width: 1px;
    background-color: #eaeaea;
}

/* 下拉菜单样式 */
.dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    min-width: 200px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-radius: 0 0 5px 5px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s ease;
    z-index: 1000;
}

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

.dropdown li {
    list-style: none;
    position: relative;
}

.dropdown-link {
    display: block;
    padding: 12px 20px;
    color: #555;
    text-decoration: none;
    border-bottom: 1px solid #f0f0f0;
    transition: all 0.2s ease;
    font-size: 14px;
}

.dropdown-link:hover {
    background-color: #f8f9fa;
    color: #3498db;
    padding-left: 25px;
}

/* 二级下拉菜单样式 */
.dropdown-submenu {
    position: absolute;
    left: 110%;
    top: 0;
    background: white;
    min-width: 180px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-radius: 0 5px 5px 5px;
    opacity: 0;
    visibility: hidden;
    transform: translateX(10px);
    transition: all 0.3s ease;
}

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

.dropdown-submenu li a {
    padding: 10px 15px;
    font-size: 13px;
}

/* 指示箭头 */
.nav-item.has-dropdown > .nav-link::after {
    content: "";
    margin-left: 5px;
    font-size: 0.7rem;
    vertical-align: middle;
}

.dropdown-link.has-submenu::after {
    content: "▶";
    float: right;
    font-size: 0.8rem;
}

/* 内容区域 */
.content {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    padding: 30px;
}

.content h2 {
    color: #2c3e50;
    margin-bottom: 20px;
    text-align: center;
}

.content p {
    line-height: 1.6;
    margin-bottom: 15px;
    color: #555;
}

.instructions {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 5px;
    margin-top: 20px;
}

.instructions h3 {
    color: #3498db;
    margin-bottom: 10px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        flex-wrap: wrap;
    }
    
    .nav-link {
        padding: 15px 20px;
        font-size: 15px;
    }
    
    .dropdown {
        position: static;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        transform: none;
        display: none;
        background: #f8f9fa;
    }
    
    .nav-item:hover .dropdown {
        display: block;
    }
    
    .dropdown-submenu {
        position: static;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        transform: none;
        display: none;
    }
    
    .dropdown li:hover .dropdown-submenu {
        display: block;
    }
}

@media (max-width: 480px) {
    .nav-menu {
        flex-direction: column;
    }
    
    .nav-item:not(:last-child)::after {
        display: none;
    }
    
    .nav-link {
        text-align: center;
        border-bottom: 1px solid #f0f0f0;
    }
    
    .nav-link:hover {
        border-bottom: 1px solid #3498db;
    }
}