* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background: radial-gradient(circle at 10% 20%, #0b0e1a, #03050a);
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* 模拟页面主体内容，让页头置顶 */
.demo-content {
    flex: 1;
    text-align: center;
    padding: 6rem 2rem;
    color: #8b9ab0;
}

/* ========== 页头样式 ========== */
.site-header {
    background: rgba(3, 5, 10, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(124, 58, 237, 0.35);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* 顶部行 (logo, 搜索, 图标) */
.header-top {
    padding: 1rem 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.logo img {
    height: 4.2rem;
    width: auto;
    filter: brightness(0) invert(1);
}

/* 科技感搜索框 */
.search-wrapper {
    flex: 1;
    max-width: 480px;
    margin: 0 1rem;
}
.search-form {
    display: flex;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 4rem;
    border: 1px solid rgba(124, 58, 237, 0.5);
    transition: all 0.2s;
}
.search-form:focus-within {
    border-color: #f97316;
    box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.2);
}
.search-form input {
    flex: 1;
    background: transparent;
    border: none;
    padding: 0.8rem 1.5rem;
    font-size: 1.4rem;
    color: #f1f5f9;
    outline: none;
}
.search-form input::placeholder {
    color: #7e8aa2;
}
.search-form button {
    background: linear-gradient(135deg, #5f548d, #7c3aed);
    border: none;
    border-radius: 4rem;
    padding: 0 1.8rem;
    margin: 3px;
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}
.search-form button:hover {
    background: #f97316;
    transform: scale(1.02);
}

/* 右侧图标组 */
.header-actions {
    display: flex;
    align-items: center;
    gap: 1.2rem;
}
.action-link {
    color: #cbd5e1;
    text-decoration: none;
    font-size: 1.4rem;
    font-weight: 500;
    transition: color 0.2s;
}
.action-link:hover {
    color: #f97316;
}
.quick-order {
    background: rgba(255, 255, 255, 0.08);
    padding: 0.5rem 1.2rem;
    border-radius: 4rem;
    border: 1px solid rgba(124, 58, 237, 0.6);
    backdrop-filter: blur(4px);
}
.quick-order:hover {
    background: #f97316;
    border-color: transparent;
    color: white;
}
.mobile-menu-toggle {
    background: none;
    border: none;
    font-size: 2rem;
    color: #cbd5e1;
    cursor: pointer;
    display: none;
}

/* 主导航栏 */
.header-nav {
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(8px);
    border-top: 1px solid rgba(124, 58, 237, 0.3);
}
.nav-menu {
    display: flex;
    justify-content: center;
    list-style: none;
    gap: 0.5rem;
    padding: 0;
    margin: 0;
    position: relative;
}
.nav-menu > li {
    position: relative;
}
.nav-menu > li > a {
    display: inline-block;
    padding: 1rem 1.6rem;
    color: #f1f5f9;
    text-decoration: none;
    font-weight: 500;
    font-size: 1.5rem;
    border-radius: 4rem;
    transition: all 0.2s;
}
.nav-menu > li > a:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #ffd966;
}

/* 自定义大菜单（Products 示例） */
.mega-menu {
    position: absolute;
    top: calc(100% + 0.8rem);
    left: 50%;
    transform: translateX(-50%);
    background: rgba(18, 22, 35, 0.98);
    backdrop-filter: blur(16px);
    border: 1px solid rgba(124, 58, 237, 0.5);
    border-radius: 2rem;
    padding: 2rem;
    min-width: 780px;
    width: max-content;
    max-width: 90vw;
    opacity: 0;
    visibility: hidden;
    transition: all 0.25s ease;
    z-index: 1000;
    pointer-events: none;
}
.nav-menu > li:hover .mega-menu {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateX(-50%) translateY(0);
}
.mega-cols {
    display: flex;
    gap: 2rem;
    justify-content: space-between;
}
.mega-col {
    flex: 1;
}
.mega-col strong {
    display: block;
    font-size: 1.6rem;
    font-weight: 700;
    color: #c084fc;
    margin-bottom: 1rem;
    padding-bottom: 0.4rem;
    border-bottom: 2px solid rgba(124, 58, 237, 0.4);
}
.mega-col ul {
    list-style: none;
    padding: 0;
    margin: 0 0 1.5rem 0;
}
.mega-col li {
    margin-bottom: 0.6rem;
}
.mega-col a {
    color: #cbd5e1;
    text-decoration: none;
    font-size: 1.4rem;
    transition: all 0.2s;
}
.mega-col a:hover {
    color: #f97316;
    transform: translateX(4px);
    display: inline-block;
}
.mega-sidebar {
    border-top: 1px solid rgba(124, 58, 237, 0.3);
    padding-top: 1.5rem;
    margin-top: 1rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
}
.mega-sidebar img {
    width: 70px;
    height: 70px;
    object-fit: cover;
    border-radius: 12px;
}
.mega-sidebar strong {
    color: white;
    display: block;
    font-size: 1.5rem;
}
.mega-sidebar p {
    font-size: 1.3rem;
    color: #8b9ab0;
}

/* 普通子菜单（Support, About）示例 */
.sub-menu {
    position: absolute;
    top: calc(100% + 0.8rem);
    left: 50%;
    transform: translateX(-50%);
    background: rgba(18, 22, 35, 0.98);
    backdrop-filter: blur(16px);
    border: 1px solid rgba(124, 58, 237, 0.5);
    border-radius: 1.2rem;
    padding: 0.6rem 0;
    min-width: 200px;
    list-style: none;
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s;
    z-index: 1000;
}
.nav-menu > li:hover .sub-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}
.sub-menu li a {
    display: block;
    padding: 0.6rem 1.5rem;
    color: #cbd5e1;
    text-decoration: none;
    font-size: 1.4rem;
    transition: all 0.2s;
}
.sub-menu li a:hover {
    background: rgba(124, 58, 237, 0.2);
    color: #f97316;
    padding-left: 2rem;
}

/* 响应式 */
@media (max-width: 900px) {
    .header-top {
        flex-wrap: wrap;
    }
    .search-wrapper {
        order: 3;
        width: 100%;
        max-width: none;
        margin: 0.5rem 0 0;
    }
    .mobile-menu-toggle {
        display: block;
    }
    .header-nav {
        display: none;
    }
    /* 简单模拟移动端菜单展开（如需交互可加JS，此处仅为样式演示） */
}