body {
    margin: 0;
    padding: 0;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}
.header-nav {
    /* 添加背景渐变 */
    background: linear-gradient(to right, #2c3e50, #34495e);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
.header-nav .container {
    padding: 15px 0;
}
.logo img {
    width: 200px;
    height: 40px;
}
.nav-items {
    display: flex;
    gap: 30px;
    width: 100%;
    order: 3;
    flex-direction: column;
    align-items: center;
    display: none;
    /* 添加背景渐变 */
    background: linear-gradient(to bottom, #34495e, #2c3e50);
    padding: 20px 0;
    border-top: 1px solid #405a74;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}
.nav-items.show {
    display: flex;
}
.nav-items a {
    text-decoration: none;
    color: #ecf0f1;
    font-weight: 500;
    font-size: 18px;
    transition: color 0.3s ease, transform 0.3s ease;
    padding: 15px 0;
    width: 80%;
    text-align: center;
    border-radius: 8px;
}
.nav-items a:hover {
    color: #3498db;
    transform: translateX(10px);
    background-color: rgba(255, 255, 255, 0.1);
}
.hamburger-menu {
    display: flex;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    /* 调整汉堡菜单位置 */
    margin-left: 15px;
}
.hamburger-menu div {
    width: 28px;
    height: 3.5px;
    background-color: #ecf0f1;
    border-radius: 3px;
    transition: all 0.3s ease;
}
.hamburger-menu:hover div {
    background-color: #3498db;
    transform: scale(1.1);
}
/* 响应式设计 */
@media (min-width: 769px) {
    .nav-items {
        display: flex;
        width: auto;
        order: 2;
        flex-direction: row;
        padding: 0;
        border-top: none;
        background: none;
        box-shadow: none;
    }
    .nav-items a {
        padding: 10px 0;
        width: auto;
        margin: 0 15px;
    }
    .nav-items a:hover {
        transform: translateY(-5px);
        background-color: transparent;
    }
    .hamburger-menu {
        display: none;
    }
}