/* roulang page: index */
:root {
            --primary: #0A66C2;
            --primary-deep: #004C99;
            --secondary-bg: #F0F6FF;
            --accent: #FF6B35;
            --accent-hover: #E55A2B;
            --neon: #00E5FF;
            --text-main: #1E293B;
            --text-secondary: #475569;
            --text-muted: #64748B;
            --text-light: #94A3B8;
            --card-bg: #FFFFFF;
            --border: #E2E8F0;
            --neutral-bg: #F8FAFC;
            --success: #10B981;
            --dark-bg: #0F172A;
            --nav-text: #CBD5E1;
            --white: #FFFFFF;
            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-lg: 16px;
            --shadow-card: 0 4px 20px rgba(0,0,0,0.04), 0 1px 3px rgba(0,0,0,0.06);
            --shadow-card-hover: 0 12px 32px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
            --shadow-btn: 0 4px 10px rgba(0,0,0,0.08);
            --transition: all 0.25s ease;
            --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Inter", system-ui, sans-serif;
            --container: 1280px;
            --section-gap: 120px;
            --card-padding: 32px;
            --grid-gap: 32px;
        }

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

        html {
            scroll-behavior: smooth;
            font-size: 16px;
        }

        body {
            font-family: var(--font-sans);
            color: var(--text-main);
            background-color: var(--white);
            line-height: 1.7;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: var(--transition);
        }

        button, .btn {
            cursor: pointer;
            font-family: inherit;
            border: none;
            outline: none;
            transition: var(--transition);
        }

        .container {
            max-width: var(--container);
            margin: 0 auto;
            padding: 0 24px;
            width: 100%;
        }

        /* 导航栏：暗色霓虹内容导航 */
        .site-header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 72px;
            background: rgba(15, 23, 42, 0.85);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            z-index: 1000;
            border-bottom: 1px solid rgba(255,255,255,0.08);
            display: flex;
            align-items: center;
        }

        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
        }

        .logo {
            font-size: 24px;
            font-weight: 700;
            color: var(--white);
            letter-spacing: 1px;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .logo-icon {
            width: 32px;
            height: 32px;
            background: linear-gradient(135deg, var(--neon), var(--primary));
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: 700;
            font-size: 18px;
        }

        .nav-menu {
            display: flex;
            align-items: center;
            gap: 28px;
            list-style: none;
        }

        .nav-link {
            font-size: 15px;
            font-weight: 500;
            color: var(--nav-text);
            padding: 8px 0;
            position: relative;
            transition: color 0.2s;
        }
        .nav-link:hover {
            color: var(--white);
        }
        .nav-link.active {
            color: var(--white);
            font-weight: 600;
        }
        .nav-link.active::after {
            content: '';
            position: absolute;
            bottom: -4px;
            left: 0;
            width: 100%;
            height: 3px;
            background: var(--neon);
            border-radius: 3px;
            box-shadow: 0 0 8px rgba(0,229,255,0.6);
        }

        .btn-primary {
            background: var(--accent);
            color: var(--white);
            padding: 14px 32px;
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 15px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 4px 12px rgba(255,107,53,0.25);
            transition: all 0.25s;
            white-space: nowrap;
        }
        .btn-primary:hover {
            background: var(--accent-hover);
            box-shadow: 0 0 16px rgba(255,107,53,0.5);
            transform: translateY(-1px);
        }

        .btn-outline {
            border: 2px solid var(--primary);
            color: var(--primary);
            background: transparent;
            padding: 14px 32px;
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 15px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            white-space: nowrap;
        }
        .btn-outline:hover {
            background: var(--primary);
            color: var(--white);
            box-shadow: var(--shadow-btn);
        }

        .btn-white {
            background: white;
            color: var(--primary);
            padding: 14px 32px;
            border-radius: var(--radius-sm);
            font-weight: 700;
            box-shadow: var(--shadow-card);
        }
        .btn-white:hover {
            background: #f1f5f9;
            box-shadow: var(--shadow-card-hover);
        }

        .text-link {
            color: var(--primary);
            font-weight: 500;
            border-bottom: 1px solid currentColor;
            transition: color 0.2s;
        }
        .text-link:hover {
            color: var(--accent);
        }

        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            background: transparent;
            border: none;
            cursor: pointer;
        }
        .hamburger span {
            width: 24px;
            height: 2px;
            background: white;
            border-radius: 4px;
            transition: 0.3s;
        }

        /* 通用板块 */
        section {
            padding: var(--section-gap) 0;
        }

        .section-title {
            font-size: 36px;
            font-weight: 600;
            line-height: 1.3;
            margin-bottom: 16px;
            color: var(--text-main);
        }
        .section-sub {
            font-size: 18px;
            color: var(--text-secondary);
            max-width: 680px;
            margin: 0 auto 48px;
            text-align: center;
        }

        .grid-3 {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: var(--grid-gap);
        }
        .grid-2 {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: var(--grid-gap);
        }

        .card {
            background: var(--card-bg);
            border-radius: var(--radius-md);
            padding: var(--card-padding);
            box-shadow: var(--shadow-card);
            border: 1px solid var(--border);
            transition: var(--transition);
        }
        .card:hover {
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-4px);
        }

        /* Hero */
        .hero {
            padding: 160px 0 100px;
            background: #FFFFFF;
            display: flex;
            align-items: center;
        }
        .hero-grid {
            display: flex;
            align-items: center;
            gap: 80px;
        }
        .hero-left {
            flex: 1;
        }
        .hero-right {
            flex: 1;
        }
        .hero-right img {
            border-radius: 24px;
            box-shadow: 0 25px 50px -12px rgba(0,0,0,0.15);
        }
        .hero h1 {
            font-size: 48px;
            font-weight: 700;
            line-height: 1.2;
            margin-bottom: 24px;
        }
        .hero h1 span {
            background: linear-gradient(135deg, var(--primary), var(--neon));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .hero p {
            font-size: 18px;
            color: var(--text-secondary);
            max-width: 480px;
            margin-bottom: 32px;
        }
        .hero-buttons {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
        }

        /* 价值主张 */
        .value-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
            text-align: center;
        }
        .value-item i {
            font-size: 32px;
            color: var(--primary);
            margin-bottom: 16px;
        }

        /* 功能图文交替 */
        .feature-row {
            display: flex;
            align-items: center;
            gap: 80px;
            margin-bottom: 80px;
        }
        .feature-row.reverse {
            flex-direction: row-reverse;
        }
        .feature-text {
            flex: 1;
        }
        .feature-img {
            flex: 1;
            background: #f1f5f9;
            border-radius: var(--radius-md);
            overflow: hidden;
            box-shadow: var(--shadow-card);
        }
        .feature-img img {
            width: 100%;
            height: auto;
        }
        .check-list {
            list-style: none;
            margin-top: 20px;
        }
        .check-list li {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 12px;
            color: var(--text-main);
        }
        .check-list li::before {
            content: "✓";
            color: var(--success);
            font-weight: bold;
            font-size: 18px;
        }

        /* 价格卡片 */
        .pricing-card {
            text-align: center;
            position: relative;
        }
        .pricing-card.featured {
            border: 2px solid var(--accent);
            transform: scale(1.03);
        }
        .badge {
            background: var(--accent);
            color: white;
            padding: 5px 16px;
            border-radius: 20px;
            font-size: 13px;
            font-weight: 600;
            position: absolute;
            top: -12px;
            left: 50%;
            transform: translateX(-50%);
        }
        .price {
            font-size: 48px;
            font-weight: 700;
            color: var(--primary);
            margin: 16px 0;
        }
        .faq-item {
            background: var(--neutral-bg);
            border-radius: var(--radius-sm);
            margin-bottom: 16px;
            overflow: hidden;
            border: 1px solid var(--border);
        }
        .faq-question {
            padding: 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 600;
            cursor: pointer;
            background: #F8FAFC;
        }
        .faq-answer {
            padding: 0 20px 20px;
            color: var(--text-secondary);
            display: none;
            border-left: 3px solid var(--primary);
            margin-left: 20px;
        }
        .faq-item.open .faq-answer {
            display: block;
        }
        .cta-banner {
            background: linear-gradient(135deg, #0A66C2 0%, #004C99 100%);
            padding: 80px 0;
            text-align: center;
            color: white;
        }
        .footer {
            background: #0F172A;
            color: #94A3B8;
            padding: 60px 0 30px;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
        }
        @media (max-width: 1024px) {
            .grid-3, .value-grid { grid-template-columns: repeat(2,1fr); }
            .feature-row { flex-direction: column; gap: 40px; }
            .hero-grid { flex-direction: column; }
            .section-title { font-size: 32px; }
        }
        @media (max-width: 768px) {
            .hamburger { display: flex; }
            .nav-menu {
                display: none;
                position: absolute;
                top: 72px;
                left: 0;
                width: 100%;
                background: #0F172A;
                flex-direction: column;
                padding: 24px;
                gap: 20px;
            }
            .nav-menu.open { display: flex; }
            .grid-3, .value-grid, .footer-grid { grid-template-columns: 1fr; }
            .hero h1 { font-size: 36px; }
        }