/* roulang page: index */
:root {
            --primary: #7B2FBE;
            --primary-glow: #9B4DE0;
            --secondary: #00F0FF;
            --secondary-glow: #33F3FF;
            --bg-dark: #0B0C10;
            --bg-card: #1A1A1E;
            --text-white: #FFFFFF;
            --text-gray: #B0B3C1;
            --text-muted: #6B6E7B;
            --accent: #FF4D2E;
            --border-subtle: rgba(255,255,255,0.06);
            --border-light: rgba(255,255,255,0.12);
            --radius-card: 16px;
            --radius-btn: 8px;
            --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
            --transition-base: 0.25s ease;
            --max-width: 1280px;
            --padding-x: 24px;
            --section-space: 120px;
            --card-gap: 24px;
            --font-h1: clamp(42px, 8vw, 56px);
            --font-h2: clamp(30px, 5vw, 40px);
            --font-h3: clamp(22px, 3vw, 28px);
            --font-h4: 20px;
            --font-body: 16px;
            --line-height-body: 1.8;
        }

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

        body {
            font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
            background-color: var(--bg-dark);
            color: var(--text-gray);
            line-height: var(--line-height-body);
            font-size: var(--font-body);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            overflow-x: hidden;
        }

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

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

        button, .btn {
            cursor: pointer;
            font-family: inherit;
            border: none;
            background: none;
            transition: all var(--transition-base);
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            font-weight: 600;
            letter-spacing: 0.02em;
            border-radius: var(--radius-btn);
            white-space: nowrap;
        }

        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 var(--padding-x);
        }

        /* 导航 */
        .header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            padding: 1rem 0;
            transition: background var(--transition-base), backdrop-filter var(--transition-base), box-shadow var(--transition-base);
            background: transparent;
        }

        .header.scrolled {
            background: rgba(11, 12, 16, 0.85);
            backdrop-filter: blur(12px);
            box-shadow: 0 2px 12px rgba(0,0,0,0.3);
            border-bottom: 2px solid rgba(123, 47, 190, 0.3);
        }

        .header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .logo {
            font-size: 28px;
            font-weight: 800;
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            letter-spacing: -0.02em;
            line-height: 1;
        }

        .nav {
            display: flex;
            gap: 2rem;
            align-items: center;
        }

        .nav a {
            font-size: 14px;
            font-weight: 500;
            letter-spacing: 0.05em;
            color: var(--text-gray);
            padding: 4px 0;
            position: relative;
            border-bottom: 2px solid transparent;
            transition: color var(--transition-base), border-color var(--transition-base);
        }

        .nav a:hover,
        .nav a.active {
            color: var(--text-white);
            border-bottom: 2px solid var(--secondary);
            padding-bottom: 2px;
        }

        .nav a.active {
            color: var(--text-white);
            border-bottom: 2px solid var(--secondary);
        }

        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            background: none;
            border: none;
            padding: 8px;
            z-index: 1001;
        }

        .hamburger span {
            display: block;
            width: 25px;
            height: 3px;
            background: var(--text-white);
            border-radius: 3px;
            transition: var(--transition-base);
        }

        .hamburger.active span:nth-child(1) {
            transform: rotate(45deg) translate(5px, 6px);
        }
        .hamburger.active span:nth-child(2) {
            opacity: 0;
        }
        .hamburger.active span:nth-child(3) {
            transform: rotate(-45deg) translate(5px, -6px);
        }

        /* Hero */
        .hero {
            min-height: 100vh;
            display: flex;
            align-items: center;
            position: relative;
            background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
            background-attachment: fixed;
            margin-bottom: 0;
        }

        .hero::before {
            content: '';
            position: absolute;
            inset: 0;
            background: radial-gradient(ellipse at center, rgba(11,12,16,0.3) 0%, rgba(11,12,16,0.9) 80%);
            z-index: 1;
        }

        .hero-content {
            position: relative;
            z-index: 2;
            max-width: 720px;
            width: 100%;
        }

        .hero h1 {
            font-size: var(--font-h1);
            font-weight: 800;
            letter-spacing: -0.03em;
            color: var(--text-white);
            margin-bottom: 1.5rem;
            line-height: 1.15;
        }

        .hero .subtitle {
            font-size: 18px;
            color: var(--text-gray);
            margin-bottom: 2.5rem;
            max-width: 580px;
            line-height: 1.6;
        }

        .btn-primary {
            background: var(--primary);
            color: #fff;
            padding: 14px 36px;
            font-size: 17px;
            box-shadow: 0 4px 15px rgba(123,47,190,0.4);
        }

        .btn-primary:hover {
            background: var(--secondary);
            box-shadow: 0 6px 20px rgba(0,240,255,0.4);
            transform: translateY(-2px);
        }

        .btn-outline {
            border: 1px solid var(--secondary);
            color: var(--secondary);
            background: transparent;
            padding: 14px 36px;
            font-size: 17px;
        }

        .btn-outline:hover {
            background: rgba(0,240,255,0.15);
            border-color: var(--text-white);
            color: var(--text-white);
        }

        .btn-lg {
            padding: 18px 44px;
            font-size: 18px;
            border-radius: 10px;
        }

        /* Sections */
        section {
            padding: var(--section-space) 0;
        }

        .section-title {
            font-size: var(--font-h2);
            font-weight: 700;
            color: var(--text-white);
            margin-bottom: 1rem;
            letter-spacing: -0.02em;
        }

        .section-subtitle {
            font-size: 18px;
            color: var(--text-gray);
            max-width: 680px;
            margin-bottom: 3.5rem;
        }

        .text-center {
            text-align: center;
        }
        .mx-auto {
            margin-left: auto;
            margin-right: auto;
        }

        /* 卡片系统 */
        .card {
            background: rgba(26, 26, 30, 0.8);
            backdrop-filter: blur(12px);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-card);
            padding: 2rem;
            box-shadow: var(--shadow-card);
            transition: transform var(--transition-base), border-color var(--transition-base);
        }

        .card:hover {
            transform: translateY(-6px);
            border-color: rgba(0,240,255,0.3);
        }

        /* 核心优势 - 非对称布局 */
        .features-grid {
            display: grid;
            grid-template-columns: 1.5fr 1fr 1fr;
            gap: var(--card-gap);
        }

        .feature-card {
            background: rgba(26,26,30,0.8);
            backdrop-filter: blur(12px);
            border: 1px solid rgba(255,255,255,0.06);
            border-radius: 16px;
            padding: 2.2rem 1.8rem;
            display: flex;
            flex-direction: column;
            transition: all 0.3s ease;
        }

        .feature-card:hover {
            transform: translateY(-6px);
            border-color: rgba(0,240,255,0.3);
        }

        .feature-icon {
            width: 64px;
            height: 64px;
            margin-bottom: 1.5rem;
            border-radius: 12px;
            object-fit: cover;
        }

        .feature-card h3 {
            font-size: var(--font-h3);
            font-weight: 700;
            color: var(--text-white);
            margin-bottom: 0.8rem;
            letter-spacing: -0.02em;
        }

        .feature-card p {
            color: var(--text-gray);
            line-height: 1.7;
        }

        /* 使用场景 - 2x2 网格 */
        .scenarios-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: var(--card-gap);
        }
        .scenario-card {
            background: rgba(26,26,30,0.8);
            backdrop-filter: blur(12px);
            border: 1px solid rgba(255,255,255,0.06);
            border-radius: 16px;
            overflow: hidden;
            transition: 0.3s;
        }
        .scenario-card:hover {
            transform: translateY(-6px);
            border-color: rgba(0,240,255,0.25);
        }
        .scenario-img {
            width: 100%;
            height: 240px;
            object-fit: cover;
        }
        .scenario-body {
            padding: 1.8rem;
        }
        .scenario-body h4 {
            font-size: 22px;
            font-weight: 700;
            color: #fff;
            margin-bottom: 0.5rem;
        }

        /* 案例卡片 */
        .cases-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: var(--card-gap);
        }
        .case-card {
            background: rgba(26,26,30,0.8);
            backdrop-filter: blur(12px);
            border-left: 3px solid var(--secondary);
            border-radius: 0 16px 16px 0;
            padding: 1.8rem;
            transition: 0.3s;
        }
        .case-card:hover {
            transform: translateY(-4px);
        }
        .case-stat {
            font-size: 36px;
            font-weight: 800;
            color: var(--secondary);
        }

        /* 价格卡片 */
        .pricing-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 28px;
            align-items: start;
        }
        .pricing-card {
            background: rgba(26,26,30,0.9);
            border: 1px solid rgba(255,255,255,0.08);
            border-radius: 20px;
            padding: 2.2rem;
            position: relative;
            transition: 0.3s;
        }
        .pricing-card.featured {
            border: 2px solid var(--primary);
            box-shadow: 0 0 25px rgba(123,47,190,0.3);
        }
        .badge {
            position: absolute;
            top: -12px;
            right: 20px;
            background: var(--accent);
            color: #fff;
            padding: 4px 14px;
            border-radius: 20px;
            font-size: 13px;
            font-weight: 700;
        }
        .price {
            font-size: 48px;
            font-weight: 800;
            color: var(--secondary);
        }

        /* FAQ */
        .faq-item {
            border-bottom: 1px solid rgba(255,255,255,0.06);
        }
        .faq-question {
            width: 100%;
            background: none;
            border: none;
            padding: 1.5rem 0;
            font-size: 18px;
            font-weight: 600;
            color: var(--text-white);
            display: flex;
            justify-content: space-between;
            align-items: center;
            text-align: left;
            cursor: pointer;
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease;
            color: var(--text-gray);
            padding: 0 0;
            line-height: 1.8;
        }
        .faq-item.active .faq-answer {
            max-height: 300px;
            padding-bottom: 1.2rem;
        }

        /* CTA Banner */
        .cta-banner {
            background: var(--bg-dark);
            background-image: radial-gradient(circle at 30% 40%, rgba(123,47,190,0.15) 0%, transparent 50%);
            padding: 5rem 0;
            text-align: center;
            border-top: 1px solid rgba(255,255,255,0.05);
        }

        /* Footer */
        .footer {
            background: var(--bg-card);
            padding: 4rem 0 2rem;
            color: var(--text-muted);
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr;
            gap: 2.5rem;
        }

        @media (max-width: 1024px) {
            .features-grid { grid-template-columns: 1fr 1fr; }
            .cases-grid { grid-template-columns: 1fr 1fr; }
            .pricing-grid { grid-template-columns: 1fr 1fr; }
        }

        @media (max-width: 768px) {
            .nav { display: none; }
            .hamburger { display: flex; }
            .nav-mobile {
                display: none;
                position: fixed;
                top: 0; left: 0;
                width: 100%; height: 100%;
                background: rgba(11,12,16,0.95);
                backdrop-filter: blur(20px);
                flex-direction: column;
                align-items: center;
                justify-content: center;
                gap: 2.5rem;
                z-index: 999;
            }
            .nav-mobile.open { display: flex; }
            .features-grid, .scenarios-grid, .cases-grid, .pricing-grid, .footer-grid {
                grid-template-columns: 1fr;
            }
            .hero h1 { font-size: 38px; }
        }