/* ===== RESET & BASE ===== */
        * { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            line-height: 1.7;
            color: #333;
            background: #fff;
        }
        a { color: #1a73e8; text-decoration: none; transition: color .2s; }
        a:hover { color: #1557b0; }
        img { max-width: 100%; height: auto; }

        /* ===== NAV BAR ===== */
        .site-nav {
            background: #fff;
            border-bottom: 1px solid #e8eaed;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: 0 1px 3px rgba(0,0,0,.06);
        }
        .nav-inner {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 24px;
            height: 64px;
        }
        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 22px;
            font-weight: 700;
            color: #1a1a1a;
            text-decoration: none;
        }
        .nav-logo span { color: #1a73e8; }
        .nav-logo-img {
            width: 36px;
            height: 36px;
            border-radius: 8px;
        }
        .nav-logo-sub {
            font-size: 11px;
            font-weight: 400;
            color: #555;
            display: block;
            line-height: 1;
            margin-top: 2px;
        }
        .nav-menu {
            display: flex;
            list-style: none;
            gap: 0;
        }
        .nav-menu > li {
            position: relative;
        }
        .nav-menu > li > a {
            display: block;
            padding: 20px 16px;
            color: #444;
            font-size: 15px;
            font-weight: 500;
            text-decoration: none;
            border-bottom: 3px solid transparent;
            transition: all .2s;
        }
        .nav-menu > li > a:hover,
        .nav-menu > li.active > a {
            color: #1a73e8;
            border-bottom-color: #1a73e8;
        }
        /* Dropdown */
        .nav-dropdown {
            display: none;
            position: absolute;
            top: 100%;
            left: 0;
            background: #fff;
            min-width: 200px;
            border-radius: 0 0 8px 8px;
            box-shadow: 0 8px 24px rgba(0,0,0,.12);
            padding: 8px 0;
            z-index: 100;
        }
        .nav-menu > li:hover .nav-dropdown {
            display: block;
        }
        .nav-dropdown a {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 10px 20px;
            color: #444;
            font-size: 14px;
            text-decoration: none;
            transition: background .15s;
        }
        .nav-dropdown a:hover {
            background: #f0f5ff;
            color: #1a73e8;
        }
        .nav-dropdown svg {
            flex-shrink: 0;
        }
        .dropdown-arrow {
            margin-left: 4px;
            transition: transform .2s;
        }
        .has-dropdown:hover .dropdown-arrow {
            transform: rotate(180deg);
        }
        /* Nav right: mobile user + desktop auth + console */
        .nav-right {
            display: flex;
            align-items: center;
            gap: 12px;
        }
        .nav-mobile-user {
            display: flex;
            width: 36px;
            height: 36px;
            border-radius: 50%;
            background: #f0f5ff;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            transition: background .15s;
        }
        .nav-mobile-user:hover { background: #e0ecff; }
        .nav-mobile-user svg { color: #1a73e8; }
        .nav-mobile-user img {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            object-fit: cover;
        }
        .nav-desktop-auth {
            display: flex;
            align-items: center;
            gap: 8px;
            font-size: 14px;
        }
        .nav-desktop-auth a {
            padding: 6px 14px;
            border-radius: 4px;
            font-size: 14px;
        }
        .nav-desktop-auth .btn-login {
            background: #1a73e8;
            color: #fff !important;
            border-radius: 4px;
        }
        .nav-desktop-auth .btn-login:hover {
            background: #1557b0;
        }
        /* Logged-in user area */
        .nav-user {
            display: none;
            align-items: center;
            gap: 8px;
            position: relative;
            cursor: pointer;
            padding: 4px 8px;
            border-radius: 20px;
            transition: background .15s;
        }
        .nav-user:hover { background: #f5f5f5; }
        .nav-user-avatar {
            width: 32px;
            height: 32px;
            border-radius: 50%;
            background: #1a73e8;
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 14px;
            font-weight: 600;
        }
        .nav-user-name {
            font-size: 14px;
            color: #333;
            max-width: 80px;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }
        .nav-user::after {
            content: '';
            position: absolute;
            bottom: -6px;
            left: 0;
            right: 0;
            height: 6px;
        }
        .nav-user-dropdown {
            display: none;
            position: absolute;
            top: calc(100% + 4px);
            right: 0;
            background: #fff;
            min-width: 160px;
            border-radius: 8px;
            box-shadow: 0 8px 24px rgba(0,0,0,.12);
            padding: 8px 0;
            z-index: 100;
        }
        .nav-user:hover .nav-user-dropdown { display: block; }
        .nav-user-dropdown a {
            display: block;
            padding: 8px 16px;
            color: #444;
            font-size: 14px;
            text-decoration: none;
        }
        .nav-user-dropdown a:hover {
            background: #f0f5ff;
            color: #1a73e8;
        }
        .nav-user-dropdown .divider {
            height: 1px;
            background: #e8eaed;
            margin: 4px 0;
        }
        /* Quick links: 文档 / 备案 / 控制台 */
        .nav-quick-links {
            display: flex;
            align-items: center;
            gap: 16px;
        }
        .nav-quick-links a {
            font-size: 14px;
            color: #555;
            text-decoration: none;
            transition: color .15s;
            white-space: nowrap;
        }
        .nav-quick-links a:hover {
            color: #1a73e8;
        }
        /* 默认隐藏登录后的用户区域（由JS控制显示） */
        #navUser { display: none; }
        #mobileUserBtn { display: none; }
        #navAuth { display: block; }
        /* Mobile nav */
        .nav-toggle {
            display: none;
            background: none;
            border: none;
            cursor: pointer;
            padding: 8px;
        }
        .nav-toggle span {
            display: block;
            width: 22px;
            height: 2px;
            background: #333;
            margin: 5px 0;
            border-radius: 1px;
            transition: all .3s;
        }

        /* ===== HERO ===== */
        .hero {
            background: linear-gradient(135deg, #1a73e8 0%, #0d47a1 100%);
            color: #fff;
            padding: 80px 24px;
            margin-top: 4px;
            text-align: center;
        }
        .hero-inner {
            max-width: 800px;
            margin: 0 auto;
        }
        .hero h1 {
            font-size: 40px;
            font-weight: 700;
            margin-bottom: 16px;
            line-height: 1.3;
        }
        .hero p {
            font-size: 18px;
            opacity: .9;
            margin-bottom: 32px;
            line-height: 1.6;
        }
        .hero-actions {
            display: flex;
            gap: 16px;
            justify-content: center;
            flex-wrap: wrap;
        }
        .btn {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 12px 28px;
            border-radius: 6px;
            font-size: 16px;
            font-weight: 500;
            text-decoration: none;
            transition: all .2s;
        }
        .btn-white {
            background: #fff;
            color: #1a73e8 !important;
        }
        .btn-white:hover { background: #f0f5ff; }
        .btn-outline-white {
            border: 1.5px solid rgba(255,255,255,.6);
            color: #fff !important;
            background: transparent;
        }
        .btn-outline-white:hover {
            background: rgba(255,255,255,.1);
            border-color: #fff;
        }
        .btn-primary {
            background: #1a73e8;
            color: #fff !important;
        }
        .btn-primary:hover { background: #1557b0; }
        .btn-outline {
            border: 1.5px solid #1a73e8;
            color: #1a73e8 !important;
            background: transparent;
        }
        .btn-outline:hover {
            background: #f0f5ff;
        }

        /* ===== SECTION COMMON ===== */
        .section {
            padding: 72px 24px;
        }
        .section-alt {
            background: #f8fafc;
        }
        .section-header {
            text-align: center;
            max-width: 640px;
            margin: 0 auto 48px;
        }
        .section-header h2 {
            font-size: 28px;
            color: #1a1a1a;
            margin-bottom: 12px;
        }
        .section-header p {
            font-size: 16px;
            color: #666;
        }
        .section-inner {
            max-width: 1200px;
            margin: 0 auto;
        }

        /* ===== PRODUCT GRID ===== */
        .product-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
        }
        .product-card {
            background: #fff;
            border: 1px solid #e8eaed;
            border-radius: 12px;
            padding: 32px 24px;
            text-align: center;
            transition: all .25s;
            text-decoration: none;
            display: block;
        }
        .product-card:hover {
            border-color: #1a73e8;
            box-shadow: 0 8px 24px rgba(26,115,232,.1);
            transform: translateY(-2px);
        }
        .product-icon {
            width: 56px;
            height: 56px;
            margin: 0 auto 16px;
            background: #f0f5ff;
            border-radius: 14px;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .product-card:hover .product-icon {
            background: #1a73e8;
        }
        .product-card:hover .product-icon svg {
            stroke: #fff;
        }
        .product-icon svg {
            stroke: #1a73e8;
            transition: stroke .25s;
        }
        .product-card h3 {
            font-size: 17px;
            color: #1a1a1a;
            margin-bottom: 8px;
        }
        .product-card p {
            font-size: 14px;
            color: #666;
            line-height: 1.5;
        }

        /* ===== FEATURES ===== */
        .feature-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 32px;
        }
        .feature-item {
            text-align: center;
        }
        .feature-num {
            font-size: 36px;
            font-weight: 700;
            color: #1a73e8;
            line-height: 1;
            margin-bottom: 8px;
        }
        .feature-label {
            font-size: 15px;
            color: #555;
            font-weight: 500;
        }
        .feature-desc {
            font-size: 13px;
            color: #888;
            margin-top: 4px;
        }

        /* ===== SOLUTION CARDS ===== */
        .solution-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .solution-card {
            background: #fff;
            border: 1px solid #e8eaed;
            border-radius: 12px;
            padding: 36px 28px;
            transition: all .25s;
        }
        .solution-card:hover {
            border-color: #1a73e8;
            box-shadow: 0 8px 24px rgba(26,115,232,.08);
        }
        .solution-card h3 {
            font-size: 20px;
            color: #1a1a1a;
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .solution-card ul {
            list-style: none;
            padding: 0;
        }
        .solution-card li {
            padding: 6px 0;
            font-size: 14px;
            color: #555;
            display: flex;
            align-items: center;
            text-align: center;
            gap: 8px;
        }
        /* 圆点样式已移除，各页面自行定义 li::before */
        .solution-tag {
            display: inline-block;
            background: #f0f5ff;
            color: #1a73e8;
            font-size: 12px;
            padding: 2px 10px;
            border-radius: 10px;
            margin-bottom: 16px;
        }

        /* ===== CTA ===== */
        .cta {
            background: linear-gradient(135deg, #1a73e8 0%, #0d47a1 100%);
            color: #fff;
            text-align: center;
            padding: 64px 24px;
        }
        .cta h2 {
            font-size: 28px;
            margin-bottom: 12px;
        }
        .cta p {
            font-size: 16px;
            opacity: .9;
            margin-bottom: 28px;
            max-width: 500px;
            margin-left: auto;
            margin-right: auto;
        }

        /* ===== FOOTER ===== */
        .site-footer {
            background: #1a1a2e;
            color: #aab;
            padding: 48px 24px 24px;
        }
        .footer-inner {
            max-width: 1200px;
            margin: 0 auto;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
            gap: 40px;
            padding-bottom: 32px;
            border-bottom: 1px solid rgba(255,255,255,.08);
        }
        .footer-brand h3 {
            color: #fff;
            font-size: 20px;
            margin-bottom: 12px;
        }
        .footer-brand p {
            font-size: 14px;
            line-height: 1.7;
        }
        .footer-col h4 {
            color: #fff;
            font-size: 15px;
            margin-bottom: 16px;
        }
        .footer-col a {
            display: block;
            color: #aab;
            font-size: 14px;
            padding: 4px 0;
            text-decoration: none;
            transition: color .2s;
        }
        .footer-col a:hover { color: #fff; }
        .footer-bottom {
            display: flex;
            flex-direction: column;
            align-items: center;
            text-align: center;
            padding-top: 24px;
            font-size: 13px;
            gap: 6px;
        }
        .footer-bottom a {
            color: #aab;
            text-decoration: none;
        }
        .footer-bottom a:hover { color: #fff; }
        .footer-icp { display: flex; gap: 16px; flex-wrap: wrap; justify-content: center; }
        .license-mobile { display: none; }

        /* ===== RESPONSIVE ===== */
        @media (max-width: 1024px) {
            .nav-menu > li > a { padding: 20px 10px; font-size: 14px; }
            .nav-logo-sub { display: none; }
            .nav-quick-links { display: none; }
            .nav-desktop-auth { display: none; }
            .nav-user { display: none !important; }
            .product-grid { grid-template-columns: repeat(2, 1fr); }
            .feature-grid { grid-template-columns: repeat(2, 1fr); }
            .solution-grid { grid-template-columns: 1fr; }
            .footer-grid { grid-template-columns: 1fr 1fr; }
        }
        @media (max-width: 768px) {
            .nav-inner { gap: 8px; }
            .nav-right { margin-right: 0; gap: 8px; }
            .hero h1 { font-size: 28px; }
            .hero p { font-size: 16px; }
            .product-grid { grid-template-columns: 1fr; }
            .feature-grid { grid-template-columns: repeat(2, 1fr); gap: 20px; }
            .footer-grid { grid-template-columns: 1fr; gap: 24px; }
            .footer-bottom { align-items: center;
            text-align: center; text-align: left; }
            .section { padding: 48px 16px; }
            .license-detail { display: none; }
            .license-desktop { display: none; }
            .license-mobile { display: inline; font-size: 12px; color: #99a; line-height: 1.6; }
            .footer-icp { flex-direction: column; gap: 2px; align-items: center; }
        }

        @media (max-width: 480px) {
            .nav-user-name { display: none; }
            .hero-actions { flex-direction: column; align-items: center; }
        }

        /* ===== MEGA MENU (Desktop) ===== */
        .mega-menu {
            display: none;
            position: fixed;
            top: 66px;
            left: 0;
            right: 0;
            background: #fff;
            box-shadow: 0 4px 6px -2px rgba(0,0,0,.07);
            z-index: 100;
            padding: 24px 0;
        }
        .has-mega:hover .mega-menu,
        .has-mega.mega-open .mega-menu {
            display: block;
        }
        .mega-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 0;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }
        .mega-column {
            display: flex;
            flex-direction: column;
            padding: 0 12px;
        }
        .mega-column:not(:first-child) {
            border-left: 1px solid #f0f0f0;
        }
        .mega-column-title {
            font-size: 13px;
            font-weight: 600;
            color: #1a73e8;
            letter-spacing: 0.5px;
            padding: 7px 12px;
            margin-bottom: 6px;
            background: linear-gradient(135deg, #f0f5ff, #e8f0fe);
            border-radius: 6px;
            border-bottom: none;
        }
        .mega-item {
            display: flex;
            align-items: flex-start;
            gap: 14px;
            padding: 12px 14px;
            border-radius: 8px;
            text-decoration: none;
            color: #333;
            transition: all .2s;
            margin: 3px 0;
            border: 1px solid transparent;
        }
        .mega-item:hover {
            background: #f0f5ff;
            border-color: #d4e4fc;
        }
        .mega-item svg {
            flex-shrink: 0;
            margin-top: 2px;
        }
        .mega-item-text {
            display: flex;
            flex-direction: column;
            gap: 4px;
        }
        .mega-title {
            font-size: 15px;
            font-weight: 600;
            color: #1a1a2e;
        }
        .mega-desc {
            font-size: 13px;
            color: #888;
            line-height: 1.5;
        }
        /* 无链接的一级菜单（纯 hover 触发子菜单） */
        .mega-parent-link {
            display: block;
            padding: 20px 16px;
            color: #444;
            font-size: 15px;
            font-weight: 500;
            text-decoration: none;
            border-bottom: 3px solid transparent;
            transition: color .2s, border-color .2s;
            cursor: pointer;
        }
        .mega-parent-link:hover,
        .has-mega:hover .mega-parent-link {
            color: #1a73e8;
            border-bottom-color: #1a73e8;
        }
        /* 小尺寸 mega menu（生态合作等子项较少的面板） */
        .mega-menu-sm {
            padding: 16px 0;
        }
        .mega-grid-sm {
            grid-template-columns: repeat(3, 1fr);
            gap: 4px;
            max-width: 900px;
        }

        /* ===== MOBILE SIDE NAV ===== */
        .mobile-nav-overlay {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0,0,0,.4);
            z-index: 998;
        }
        .mobile-nav-overlay.open {
            display: block;
        }
        .mobile-nav-panel {
            position: fixed;
            top: 0;
            left: 0;
            bottom: 0;
            width: 100%;
            max-width: 420px;
            background: #fff;
            z-index: 999;
            display: none;
            flex-direction: column;
            overflow: hidden;
        }
        .mobile-nav-panel.open {
            display: flex;
        }
        .mobile-nav-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 14px 16px;
            border-bottom: 1px solid #e8eaed;
            flex-shrink: 0;
        }
        .mobile-nav-header h3 {
            font-size: 16px;
            color: #1a1a2e;
            margin: 0;
        }
        .mobile-nav-close {
            width: 32px;
            height: 32px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: none;
            border: none;
            cursor: pointer;
            color: #666;
            font-size: 20px;
        }
        .mobile-nav-body {
            display: flex;
            flex: 1;
            overflow: hidden;
        }
        .mobile-nav-categories {
            width: 120px;
            flex-shrink: 0;
            overflow-y: auto;
            border-right: 1px solid #e8eaed;
            padding: 8px 0;
        }
        .mobile-nav-cat-item {
            display: block;
            padding: 14px 16px;
            font-size: 14px;
            color: #555;
            text-decoration: none;
            border-left: 3px solid transparent;
            transition: all .15s;
        }
        .mobile-nav-cat-item:hover,
        .mobile-nav-cat-item.active {
            color: #1a73e8;
            background: #f0f5ff;
            border-left-color: #1a73e8;
        }
        .mobile-nav-subitems {
            flex: 1;
            overflow-y: auto;
            padding: 12px 16px;
        }
        .mobile-nav-subitem {
            display: block;
            padding: 12px 14px;
            font-size: 14px;
            color: #333;
            text-decoration: none;
            border-radius: 8px;
            margin-bottom: 2px;
            transition: background .15s;
        }
        .mobile-nav-subitem:hover {
            background: #f0f5ff;
            color: #1a73e8;
        }
        .mobile-nav-subitem.active {
            background: #e8f0fe;
            color: #1a73e8;
            font-weight: 600;
            border-left: 3px solid #1a73e8;
            padding-left: 11px;
        }
        .mobile-nav-subitem.active .sub-desc {
            color: #5f8dee;
        }
        .mobile-nav-subitem .sub-desc {
            display: block;
            font-size: 12px;
            color: #999;
            margin-top: 2px;
        }
        .mobile-nav-subgroup-title {
            font-size: 12px;
            font-weight: 600;
            color: #1a73e8;
            letter-spacing: 0.5px;
            padding: 10px 14px 6px;
            margin-top: 8px;
            background: linear-gradient(135deg, #f0f5ff 0%, #e8f0fe 100%);
            border-radius: 6px;
            margin-left: 4px;
            margin-right: 4px;
        }
        .mobile-nav-subgroup-title:first-child {
            margin-top: 0;
        }
        .mobile-nav-footer {
            padding: 12px 16px;
            border-top: 1px solid #e8eaed;
            flex-shrink: 0;
        }
        .mobile-nav-footer a {
            display: block;
            padding: 10px 14px;
            font-size: 14px;
            color: #555;
            text-decoration: none;
        }
        .mobile-nav-footer a:hover {
            color: #1a73e8;
        }

        @media (max-width: 768px) {
            .nav-menu,
            .nav-desktop-auth,
            .nav-user,
            .nav-quick-links {
                display: none !important;
            }
            .nav-toggle {
                display: block;
                margin-left: auto;
            }
        }