/* roulang page: index */
:root {
            --primary-red: #E63946;
            --primary-red-dark: #C1121F;
            --deep-gray: #1D1D1D;
            --track-white: #F8F9FA;
            --victory-gold: #F4A261;
            --card-border: #E9ECEF;
            --text-body: #495057;
            --text-muted: #6C757D;
            --white: #ffffff;
            --shadow-sm: 0 4px 20px rgba(0,0,0,0.06);
            --shadow-md: 0 12px 30px rgba(0,0,0,0.12);
            --border-radius-card: 12px;
            --border-radius-btn: 50px;
            --transition: all 0.3s ease;
            --font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
        }

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

        html {
            scroll-behavior: smooth;
        }

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

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

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

        button, .btn {
            cursor: pointer;
            font-family: inherit;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            white-space: nowrap;
            font-weight: 700;
            letter-spacing: 0.05em;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 2rem;
        }

        /* 导航栏 */
        header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid var(--card-border);
            padding: 1rem 0;
        }
        .nav-container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 2rem;
        }
        .logo {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--deep-gray);
            display: flex;
            align-items: baseline;
            gap: 0.3rem;
        }
        .logo span:first-child {
            color: var(--primary-red);
        }
        .logo .version-tag {
            font-size: 0.9rem;
            font-weight: 500;
            background: var(--primary-red);
            color: white;
            padding: 0.15rem 0.6rem;
            border-radius: 20px;
            margin-left: 0.3rem;
            letter-spacing: 0.02em;
        }
        .nav-menu {
            display: flex;
            align-items: center;
            gap: 2rem;
            list-style: none;
        }
        .nav-menu a {
            font-weight: 600;
            color: var(--deep-gray);
            position: relative;
            padding: 0.2rem 0;
        }
        .nav-menu a::after {
            content: '';
            position: absolute;
            bottom: -4px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--primary-red);
            transition: width 0.3s;
        }
        .nav-menu a:hover::after,
        .nav-menu a.active::after {
            width: 100%;
        }
        .btn-primary {
            background: var(--primary-red);
            color: white;
            border: none;
            padding: 0.8rem 2.2rem;
            border-radius: var(--border-radius-btn);
            box-shadow: 0 4px 12px rgba(230,57,70,0.3);
        }
        .btn-primary:hover {
            background: var(--primary-red-dark);
            box-shadow: 0 0 18px rgba(230,57,70,0.5);
            transform: translateY(-1px);
        }
        .btn-outline {
            background: transparent;
            border: 2px solid var(--primary-red);
            color: var(--primary-red);
            padding: 0.7rem 2rem;
            border-radius: var(--border-radius-btn);
        }
        .btn-outline:hover {
            background: var(--primary-red);
            color: white;
        }
        .hamburger {
            display: none;
            font-size: 1.8rem;
            cursor: pointer;
            color: var(--deep-gray);
        }
        .mobile-menu-overlay {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: linear-gradient(135deg, var(--deep-gray), var(--primary-red-dark));
            z-index: 2000;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 2.5rem;
        }
        .mobile-menu-overlay a {
            color: white;
            font-size: 2rem;
            font-weight: 700;
        }
        .close-menu {
            position: absolute;
            top: 2rem;
            right: 2rem;
            font-size: 2.5rem;
            color: white;
            cursor: pointer;
        }

        /* 板块间距 */
        section {
            padding: 5rem 0;
        }

        /* 首屏 Hero */
        .hero {
            background: linear-gradient(135deg, #1D1D1D 0%, #C1121F 100%);
            position: relative;
            overflow: hidden;
            color: white;
        }
        .hero::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: repeating-linear-gradient(45deg, rgba(255,255,255,0.03) 0px, rgba(255,255,255,0.03) 2px, transparent 2px, transparent 8px);
            pointer-events: none;
        }
        .hero .container {
            display: flex;
            align-items: center;
            gap: 3rem;
            position: relative;
            z-index: 2;
        }
        .hero-left {
            flex: 1;
        }
        .hero-left h1 {
            font-size: clamp(2.5rem, 6vw, 4rem);
            font-weight: 800;
            letter-spacing: -0.02em;
            line-height: 1.2;
            margin-bottom: 1.5rem;
        }
        .hero-left .subtitle {
            font-size: 1.2rem;
            margin-bottom: 2rem;
            opacity: 0.9;
        }
        .hero-buttons {
            display: flex;
            flex-wrap: wrap;
            gap: 1rem;
        }
        .hero-right {
            flex: 1;
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .hero-right img {
            max-width: 100%;
            border-radius: 16px;
            box-shadow: 0 20px 40px rgba(0,0,0,0.5);
            transform: perspective(1000px) rotateY(-5deg);
            transition: transform 0.3s;
        }
        .hero-right img:hover {
            transform: perspective(1000px) rotateY(0deg);
        }

        /* 区块标题 */
        .section-title {
            text-align: center;
            margin-bottom: 3rem;
        }
        .section-title h2 {
            font-size: clamp(2rem, 4vw, 2.8rem);
            font-weight: 700;
            color: var(--deep-gray);
        }
        .section-title p {
            color: var(--text-muted);
            max-width: 600px;
            margin: 0.5rem auto 0;
        }

        /* 功能卡片 */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
            gap: 2rem;
        }
        .feature-card {
            background: white;
            padding: 2rem;
            border-radius: var(--border-radius-card);
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--card-border);
            transition: var(--transition);
            text-align: center;
        }
        .feature-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-md);
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--primary-red);
            margin-bottom: 1rem;
        }
        .feature-card h3 {
            font-size: 1.25rem;
            font-weight: 600;
            color: var(--deep-gray);
            margin-bottom: 0.5rem;
        }

        /* 场景卡片 */
        .scenarios .container {
            display: flex;
            flex-direction: column;
            gap: 2.5rem;
        }
        .scenario-item {
            display: flex;
            align-items: center;
            gap: 2rem;
            background: white;
            border-radius: var(--border-radius-card);
            overflow: hidden;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--card-border);
        }
        .scenario-item.reverse {
            flex-direction: row-reverse;
        }
        .scenario-img {
            flex: 1;
            min-height: 250px;
        }
        .scenario-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        .scenario-text {
            flex: 1;
            padding: 2rem;
        }
        .scenario-text h3 {
            color: var(--deep-gray);
            margin-bottom: 0.8rem;
        }

        /* 数据卡片 */
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 1.5rem;
        }
        .stat-card {
            background: white;
            padding: 2rem;
            border-radius: var(--border-radius-card);
            text-align: center;
            box-shadow: var(--shadow-sm);
            border-left: 4px solid var(--victory-gold);
        }
        .stat-number {
            font-size: 2.5rem;
            font-weight: 800;
            color: var(--victory-gold);
        }

        /* 价格卡片 */
        .pricing-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 2rem;
            align-items: start;
        }
        .pricing-card {
            background: white;
            padding: 2.5rem 2rem;
            border-radius: var(--border-radius-card);
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--card-border);
            text-align: center;
            transition: var(--transition);
        }
        .pricing-card.recommended {
            border: 2px solid var(--primary-red);
            transform: scale(1.02);
            box-shadow: var(--shadow-md);
        }
        .badge {
            background: var(--primary-red);
            color: white;
            padding: 0.3rem 1rem;
            border-radius: 20px;
            font-size: 0.85rem;
            display: inline-block;
            margin-bottom: 1rem;
        }
        .price {
            font-size: 2.2rem;
            font-weight: 800;
            color: var(--victory-gold);
            margin: 1rem 0;
        }

        /* FAQ */
        .faq-item {
            background: white;
            border-radius: var(--border-radius-card);
            margin-bottom: 1rem;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--card-border);
            overflow: hidden;
        }
        .faq-question {
            padding: 1.2rem 2rem;
            font-weight: 600;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            background: var(--track-white);
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.4s ease;
            background: white;
            padding: 0 2rem;
        }
        .faq-item.active .faq-answer {
            max-height: 200px;
            padding: 1rem 2rem;
        }

        /* CTA 横幅 */
        .cta-band {
            background: var(--deep-gray);
            position: relative;
            overflow: hidden;
            text-align: center;
            color: white;
        }
        .cta-band::after {
            content: "";
            position: absolute;
            width: 100%;
            height: 100%;
            top: 0;
            left: 0;
            background: radial-gradient(circle at 30% 40%, rgba(230,57,70,0.3) 0%, transparent 50%);
        }
        .cta-band h2 {
            font-size: 2.5rem;
            margin-bottom: 1.5rem;
            position: relative;
            z-index: 1;
        }

        /* 页脚 */
        footer {
            background: var(--deep-gray);
            color: #adb5bd;
            padding: 3rem 0;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 2rem;
        }
        .footer-col h4 {
            color: white;
            margin-bottom: 1rem;
        }
        .footer-bottom {
            border-top: 1px solid #343a40;
            margin-top: 2rem;
            padding-top: 1.5rem;
            text-align: center;
            font-size: 0.9rem;
        }

        @media (max-width: 768px) {
            .nav-menu { display: none; }
            .hamburger { display: block; }
            .hero .container { flex-direction: column; }
            .stats-grid { grid-template-columns: repeat(2, 1fr); }
            .scenario-item, .scenario-item.reverse { flex-direction: column; }
            .footer-grid { grid-template-columns: 1fr 1fr; }
            .pricing-grid { grid-auto-flow: column; overflow-x: auto; }
        }
        @media (max-width: 520px) {
            .container { padding: 0 1.5rem; }
            section { padding: 3rem 0; }
            .stats-grid { grid-template-columns: 1fr; }
            .footer-grid { grid-template-columns: 1fr; }
        }