/* roulang page: index */
:root {
            --primary: #0A6EFF;
            --primary-glow: rgba(10, 110, 255, 0.8);
            --secondary: #FF5C00;
            --secondary-glow: rgba(255, 92, 0, 0.7);
            --bg-deep: #0B0F19;
            --bg-dark: #111827;
            --card-bg: rgba(20, 30, 50, 0.6);
            --glass-border: rgba(255, 255, 255, 0.15);
            --text-body: #E0E0E0;
            --text-title: #FFFFFF;
            --text-muted: #9CA3AF;
            --radius-lg: 16px;
            --radius-md: 8px;
            --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
            --font-sans: 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
            --transition-speed: 0.25s ease;
        }

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

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

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

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

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

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

        button, .btn {
            cursor: pointer;
            font-family: inherit;
            border: none;
            background: none;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            transition: all var(--transition-speed);
            border-radius: var(--radius-md);
            font-weight: 600;
            letter-spacing: 0.5px;
        }

        /* 导航 */
        .header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 50;
            padding: 1rem 0;
            transition: background 0.3s ease, backdrop-filter 0.3s ease, box-shadow 0.3s ease;
            background: transparent;
        }

        .header.scrolled {
            background: rgba(11, 15, 25, 0.85);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            box-shadow: 0 4px 25px rgba(0, 0, 0, 0.4);
            border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        }

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

        .logo {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--text-title);
            letter-spacing: 1px;
            background: linear-gradient(135deg, #fff, #a0c4ff);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 2.2rem;
        }

        .nav-links a {
            font-weight: 500;
            color: var(--text-body);
            position: relative;
            padding: 0.3rem 0;
            font-size: 0.95rem;
            transition: color 0.2s;
        }

        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0%;
            height: 2px;
            background: var(--primary);
            transition: width 0.3s ease;
            border-radius: 2px;
        }

        .nav-links a:hover {
            color: #fff;
        }
        .nav-links a:hover::after {
            width: 100%;
        }

        .btn-primary {
            background: var(--primary);
            color: #fff;
            padding: 0.7rem 1.8rem;
            border-radius: var(--radius-md);
            box-shadow: 0 0 20px var(--primary-glow);
        }

        .btn-primary:hover {
            background: #1e84ff;
            box-shadow: 0 0 28px rgba(10, 110, 255, 0.9);
            transform: translateY(-2px);
        }

        .btn-outline {
            border: 1px solid var(--primary);
            color: #fff;
            padding: 0.7rem 1.8rem;
            background: transparent;
        }

        .btn-outline:hover {
            background: rgba(10, 110, 255, 0.15);
            border-color: #fff;
        }

        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            z-index: 100;
        }
        .hamburger span {
            width: 26px;
            height: 2.5px;
            background: #fff;
            border-radius: 4px;
            transition: 0.3s;
        }
        .mobile-menu {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100vh;
            background: rgba(11, 15, 23, 0.96);
            backdrop-filter: blur(20px);
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 2.5rem;
            z-index: 60;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.3s;
        }
        .mobile-menu.active {
            opacity: 1;
            pointer-events: auto;
        }

        /* Hero */
        .hero {
            padding: 10rem 0 6rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 3rem;
            background: radial-gradient(circle at 20% 30%, #0a1a3a, #0B0F19 75%);
            position: relative;
            overflow: hidden;
        }
        .hero-left {
            flex: 1;
            max-width: 580px;
        }
        .hero-left h1 {
            font-size: 3.2rem;
            font-weight: 700;
            line-height: 1.25;
            margin-bottom: 1.5rem;
            color: #fff;
        }
        .hero-left .subtitle {
            font-size: 1.15rem;
            color: var(--text-muted);
            margin-bottom: 2.2rem;
            max-width: 500px;
        }
        .hero-buttons {
            display: flex;
            gap: 1.2rem;
            flex-wrap: wrap;
        }
        .hero-right {
            flex: 1;
            position: relative;
            height: 420px;
            min-width: 320px;
        }
        .hero-bg-img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            border-radius: 24px;
            filter: brightness(0.8) contrast(1.1);
            box-shadow: 0 25px 50px -12px rgba(0,0,0,0.6);
        }
        .floating-card {
            position: absolute;
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            border: 1px solid var(--glass-border);
            border-radius: var(--radius-lg);
            padding: 1rem 1.5rem;
            color: #fff;
            font-weight: 600;
            box-shadow: 0 15px 30px rgba(0,0,0,0.5);
            display: flex;
            align-items: center;
            gap: 0.7rem;
        }
        .card-top {
            top: 15px;
            right: -15px;
        }
        .card-bottom {
            bottom: 30px;
            left: -15px;
        }

        /* 通用板块 */
        .section {
            padding: 5.5rem 0;
        }
        .section-title {
            font-size: 2.2rem;
            font-weight: 700;
            color: #fff;
            margin-bottom: 1rem;
            text-align: center;
        }
        .section-desc {
            color: var(--text-muted);
            text-align: center;
            max-width: 650px;
            margin: 0 auto 3.5rem;
        }

        /* 亮点网格 */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 2rem;
        }
        .feature-card {
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            border: 1px solid var(--glass-border);
            border-radius: var(--radius-lg);
            padding: 2rem 1.5rem;
            transition: all 0.3s;
        }
        .feature-card:hover {
            border-color: rgba(255,255,255,0.3);
            transform: translateY(-6px);
            box-shadow: 0 15px 35px rgba(10,110,255,0.2);
        }
        .feature-icon {
            font-size: 2rem;
            color: var(--primary);
            margin-bottom: 1.3rem;
        }

        /* 案例瀑布 */
        .masonry {
            columns: 3;
            column-gap: 2rem;
        }
        .case-card {
            break-inside: avoid;
            margin-bottom: 2rem;
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            border: 1px solid var(--glass-border);
            border-radius: var(--radius-lg);
            overflow: hidden;
            transition: 0.3s;
        }
        .case-card:hover {
            border-color: rgba(255,255,255,0.25);
            transform: translateY(-5px);
        }
        .case-img {
            width: 100%;
            aspect-ratio: 16/9;
            object-fit: cover;
        }
        .case-content {
            padding: 1.4rem;
        }

        /* 对比 */
        .compare-row {
            display: flex;
            gap: 2.5rem;
            align-items: center;
        }
        .compare-col {
            flex:1;
            background: rgba(20,30,50,0.5);
            border-radius: var(--radius-lg);
            padding: 2rem;
        }
        .vs-badge {
            font-size: 2rem;
            font-weight: 800;
            color: var(--secondary);
        }

        /* FAQ */
        .faq-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1.5rem;
        }
        .faq-item {
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            border: 1px solid var(--glass-border);
            border-radius: var(--radius-lg);
            padding: 1.2rem 1.8rem;
        }
        .faq-question {
            font-weight: 600;
            color: #fff;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
        }

        /* CTA */
        .cta-banner {
            background: var(--bg-dark);
            text-align: center;
            padding: 5rem 1rem;
        }
        .footer {
            background: #0a0e15;
            padding: 4rem 0 2rem;
        }

        @media (max-width: 1024px) {
            .features-grid { grid-template-columns: repeat(2,1fr); }
            .masonry { columns: 2; }
            .compare-row { flex-direction: column; }
        }
        @media (max-width: 768px) {
            .nav-links { display: none; }
            .hamburger { display: flex; }
            .hero { flex-direction: column; padding: 8rem 0 3rem; }
            .hero-right { width: 100%; height: 300px; }
            .features-grid { grid-template-columns: 1fr; }
            .masonry { columns: 1; }
            .faq-grid { grid-template-columns: 1fr; }
        }