/* roulang page: index */
:root {
            --primary: #6C3CF0;
            --primary-dark: #5a2bc9;
            --accent: #FF6B35;
            --accent-light: #ff8c62;
            --deep: #1A1040;
            --bg-light: #F8F7FC;
            --text-dark: #2D2A3A;
            --text-light: #FFFFFF;
            --text-muted: #6A6A7A;
            --border-light: #E8E7ED;
            --card-shadow: 0 8px 32px rgba(108, 60, 240, 0.08);
            --card-hover-shadow: 0 14px 44px rgba(108, 60, 240, 0.18);
            --nav-shadow: 0 2px 20px rgba(0,0,0,0.07);
            --btn-shadow-hover: 0 10px 28px rgba(255, 107, 53, 0.35);
            --danger-glow: rgba(255, 59, 59, 0.20);
            --radius-lg: 22px;
            --radius-md: 16px;
            --radius-sm: 12px;
            --radius-full: 50px;
            --gradient-main: linear-gradient(135deg, #6C3CF0 0%, #FF6B35 100%);
            --gradient-reverse: linear-gradient(135deg, #FF6B35 0%, #6C3CF0 100%);
            --gradient-dark: linear-gradient(140deg, #1A1040 0%, #2D1B5E 100%);
            --transition: 0.25s cubic-bezier(0.3, 0.1, 0.2, 1);
            --navbar-height: 72px;
            --container-max: 1200px;
            --section-padding: 90px 24px;
            --section-padding-mobile: 70px 20px;
            --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", "Noto Sans SC", system-ui, -apple-system, sans-serif;
        }

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

        html {
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }

        body {
            font-family: var(--font-stack);
            font-size: 16px;
            line-height: 1.75;
            color: var(--text-dark);
            background-color: #ffffff;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

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

        a {
            text-decoration: none;
            color: inherit;
        }

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

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

        /* Navbar */
        .navbar {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: var(--navbar-height);
            background: rgba(255, 255, 255, 0.82);
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 32px;
            z-index: 1000;
            box-shadow: var(--nav-shadow);
            border-bottom: 1px solid rgba(240, 240, 246, 0.85);
        }
        .logo {
            display: flex;
            align-items: center;
            gap: 8px;
            font-weight: 800;
            font-size: 1.6rem;
            color: #1A1040;
            letter-spacing: -0.3px;
            white-space: nowrap;
        }
        .logo-icon {
            width: 36px;
            height: 36px;
            background: var(--gradient-main);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: 700;
            font-size: 1.3rem;
        }
        .nav-menu {
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .nav-link {
            padding: 10px 20px;
            font-weight: 500;
            color: #2D2A3A;
            transition: color 0.2s, box-shadow 0.2s;
            position: relative;
            border-radius: 30px;
        }
        .nav-link:hover {
            color: var(--primary);
            background: rgba(108, 60, 240, 0.04);
        }
        .nav-cta-mobile {
            display: none;
        }
        .hamburger {
            display: none;
            flex-direction: column;
            justify-content: space-around;
            width: 24px;
            height: 20px;
            background: transparent;
            border: none;
            cursor: pointer;
            z-index: 1100;
        }
        .hamburger span {
            height: 2.5px;
            width: 100%;
            background: #2D2A3A;
            border-radius: 2px;
            transition: 0.2s;
        }
        .mobile-nav-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
            background: rgba(26, 16, 64, 0.96);
            backdrop-filter: blur(20px);
            z-index: 1050;
            display: flex;
            align-items: center;
            justify-content: center;
            flex-direction: column;
            gap: 28px;
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.35s ease;
        }
        .mobile-nav-overlay.is-open {
            opacity: 1;
            visibility: visible;
        }
        .mobile-nav-link {
            font-size: 1.8rem;
            font-weight: 600;
            color: white;
            padding: 12px 28px;
        }

        /* Sections */
        section {
            padding: var(--section-padding);
            box-sizing: border-box;
        }

        .bg-light {
            background: var(--bg-light);
        }
        .bg-dark {
            background: var(--deep);
        }

        /* Hero */
        #hero {
            position: relative;
            min-height: 100vh;
            display: flex;
            align-items: center;
            background-color: #0a0718;
            background-image: url('/assets/images/backpic/back-1.webp'), linear-gradient(150deg, rgba(26,16,64,0.82) 0%, rgba(108,60,240,0.7) 100%);
            background-size: cover;
            background-position: center 30%;
            background-blend-mode: overlay;
        }
        .hero-content {
            max-width: 760px;
            margin-top: 20px;
            animation: fadeUp 0.8s ease;
        }
        @keyframes fadeUp {
            from { opacity: 0; transform: translateY(25px); }
            to { opacity: 1; transform: none; }
        }
        .hero h1 {
            font-size: clamp(2.4rem, 6vw, 3.6rem);
            font-weight: 800;
            letter-spacing: -0.5px;
            color: #FFFFFF;
            line-height: 1.25;
            text-shadow: 0 8px 28px rgba(0,0,0,0.5);
        }
        .hero .sub {
            font-size: 1.22rem;
            color: rgba(255,255,255,0.9);
            margin: 1.5rem 0 2rem;
            max-width: 600px;
        }

        /* Buttons */
        .btn-primary {
            background: var(--gradient-main);
            color: white;
            font-weight: 700;
            padding: 0.9rem 2.6rem;
            border-radius: var(--radius-full);
            font-size: 1.1rem;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            box-shadow: 0 6px 18px rgba(108,60,240,0.2);
        }
        .btn-primary:hover {
            background: var(--gradient-reverse);
            transform: scale(1.03);
            box-shadow: var(--btn-shadow-hover);
        }
        .btn-outline {
            border: 2px solid var(--primary);
            color: var(--primary);
            background: transparent;
            font-weight: 700;
            padding: 0.8rem 2.4rem;
 border-radius: var(--radius-full);
        }
        .btn-outline:hover {
            background: rgba(108,60,240,0.07);
        }
        /* section titles */
        .section-title {
            font-size: clamp(2rem, 5vw, 2.4rem);
            font-weight: 700;
            margin-bottom: 1rem;
        }
        /* Pain points cards */
        .cards-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 28px;
            margin-top: inherit;
        }
        .pain-card {
            background: #1E1842;
            border-left: 6px solid #FF4949;
            padding: 1.8rem;
            border-radius: var(--radius-lg);
            color: #fff;
        }
        /* Solution special layout */
        .solution-dual {
            display: grid;
            grid-template-columns: 1.15fr 0.85fr;
            gap: 36px;
            align-items: center;
        }
        .highlight-badge {
            font-weight: 800;
            font-size: 3rem;
            color: var(--accent);
        }
        .faq-item {
            background: white;
            border-radius: 16px;
            margin-bottom: 14px;
            padding: 1rem 1.6rem;
            box-shadow: 0 6px 20px rgba(0,0,0,0.03);
            cursor: pointer;
        }
        .footer-links a {color: #aaa; font-size: 0.9rem;}
        @media (max-width: 768px) {
            .nav-menu {display: none;}
            .hamburger {display: flex;}
            .navbar {padding: 0 20px;}
            .solution-dual {grid-template-columns: 1fr;}
        }