body {
    background-image: url('https://static.igem.wiki/teams/5968/general/background-1.webp');
    background-size: cover;
    background-repeat: no-repeat;
    background-attachment: fixed;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}


/* 主要内容区域 */

.main-content {
    margin-top: 100px;
    /* 为固定导航栏留出空间 */
    min-height: calc(100vh - 200px);
}


/* 导航栏基础样式 */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    align-items: center;
    padding: 0 2rem;
    background: linear-gradient(to bottom, rgba(25, 39, 109, 1) 0%, rgba(25, 39, 109, 0) 98%);
    z-index: 1000;
    transition: all 0.3s ease;
    backdrop-filter: blur(5px);
}

.nav-logo {
    margin-right: auto;
}

.nav-logo-img {
    height: 70px;
    width: auto;
    transition: transform 0.3s ease;
}

.nav-logo-img:hover {
    transform: scale(1.05);
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-item {
    position: relative;
}

.nav-link {
    color: white;
    text-decoration: none;
    padding: 1rem 1.5rem;
    display: block;
    font-weight: 500;
    transition: color 0.3s ease;
    font-size: 1.1rem;
}

.nav-link:hover {
    color: #FFC000;
}

.nav-link.active {
    color: #FFC000;
}

.mega-menu {
    position: fixed;
    top: 100%;
    left: 0;
    width: 100%;
    background: linear-gradient(to right, rgba(25, 39, 109, 1) 30%, rgba(25, 39, 109, 0) 80%);
    /*background: linear-gradient(to bottom, rgba(25, 39, 109, 1) 0%, rgba(25, 39, 109, 0) 100%);*/
    display: none;
    z-index: 999;
    padding: 2rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(5px);
}

.mega-menu.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.mega-menu-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
}

.mega-menu-item {
    color: white;
    text-decoration: none;
    padding: 0.8rem 0;
    font-size: 1.1rem;
    transition: color 0.3s ease, transform 0.2s ease;
    text-align: left;
    display: block;
}

.mega-menu-item:hover {
    color: #FFC000;
    transform: translateX(5px);
}


/* 页脚样式 */

.footer {
    background: linear-gradient(to bottom, rgba(25, 39, 109, 0) 0%, rgba(25, 39, 109, 1) 100%);
    color: white;
    padding: 2rem;
    text-align: center;
    margin-top: 2rem;
    backdrop-filter: blur(5px);
}

.footer h1 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.footer p {
    margin: 0.5rem 0;
}

.footer a {
    color: #FFC000;
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}


/* 响应式设计 */

@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        padding: 1rem;
    }
    .nav-menu {
        flex-direction: column;
        width: 100%;
        margin-top: 1rem;
    }
    .nav-item {
        width: 100%;
    }
    .nav-link {
        padding: 0.8rem 0;
    }
    .mega-menu {
        position: relative;
        padding: 1rem;
    }
    .main-content {
        margin-top: 150px;
        margin-left: 1rem;
        margin-right: 1rem;
    }
}