/* roulang page: index */
:root {
            --primary: #1A5F7A;
            --primary-dark: #0D3B4A;
            --accent: #F85C3C;
            --accent-dark: #E04A2E;
            --bg: #F7F9FC;
            --card-bg: #FFFFFF;
            --dark-bg: #0D3B4A;
            --text-main: #1E293B;
            --text-sub: #64748B;
            --text-muted: #94A3B8;
            --border: #E2E8F0;
            --success: #10B981;
            --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
            --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
            --shadow-hover: 0 10px 25px rgba(0,0,0,0.1), 0 4px 10px rgba(0,0,0,0.06);
            --radius-card: 12px;
            --radius-btn: 8px;
            --section-gap: 120px;
        }

        * {
            box-sizing: border-box;
        }

        body {
            font-family: var(--font-stack);
            background: var(--bg);
            color: var(--text-main);
            margin: 0;
            padding: 0;
            line-height: 1.75;
            font-size: 16px;
            -webkit-font-smoothing: antialiased;
        }

        a {
            color: var(--primary);
            text-decoration: none;
            transition: color 0.2s;
        }

        a:hover {
            color: var(--accent);
        }

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

        button, .button {
            border-radius: var(--radius-btn);
            font-weight: 600;
            letter-spacing: 0.5px;
            transition: all 0.25s ease;
            cursor: pointer;
            border: none;
            display: inline-block;
            text-align: center;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* 导航 */
        .site-header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 100;
            background: rgba(255,255,255,0.75);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border-bottom: 1px solid rgba(226,232,240,0.5);
            box-shadow: 0 1px 4px rgba(0,0,0,0.04);
            padding: 12px 0;
            transition: background 0.3s, box-shadow 0.3s;
        }

        .site-header.scrolled {
            background: #FFFFFF;
            box-shadow: 0 2px 8px rgba(0,0,0,0.08);
        }

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

        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--primary);
            letter-spacing: -0.5px;
        }

        .logo i {
            font-size: 1.6rem;
            vertical-align: middle;
            margin-right: 5px;
            color: var(--accent);
        }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 28px;
        }

        .nav-links a {
            color: var(--text-main);
            font-weight: 500;
            font-size: 0.95rem;
            padding: 6px 0;
            border-bottom: 2px solid transparent;
            transition: border-color 0.2s, color 0.2s;
        }

        .nav-links a:hover {
            color: var(--primary);
            border-bottom-color: var(--accent);
        }

        .nav-cta {
            background: var(--accent);
            color: white !important;
            padding: 8px 20px !important;
            border-radius: var(--radius-btn);
            font-size: 0.9rem;
            border: none !important;
        }

        .nav-cta:hover {
            background: var(--accent-dark);
            color: white !important;
            transform: translateY(-1px);
        }

        .menu-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 1.6rem;
            color: var(--text-main);
        }

        /* Hero */
        .hero {
            padding: 160px 0 100px;
            background: linear-gradient(135deg, #F7F9FC 0%, #E8F0F6 100%);
            position: relative;
            overflow: hidden;
        }

        .hero .container {
            display: flex;
            align-items: center;
            gap: 40px;
        }

        .hero-left {
            flex: 1 1 60%;
        }

        .hero-right {
            flex: 1 1 40%;
            text-align: center;
        }

        .hero-right img {
            width: 100%;
            max-width: 500px;
            margin: 0 auto;
            filter: drop-shadow(0 20px 30px rgba(0,0,0,0.15));
            animation: float 6s ease-in-out infinite;
        }

        @keyframes float {
            0% { transform: translateY(0px); }
            50% { transform: translateY(-12px); }
            100% { transform: translateY(0px); }
        }

        .hero h1 {
            font-size: 3rem;
            font-weight: 700;
            line-height: 1.2;
            letter-spacing: -0.5px;
            margin-bottom: 20px;
            color: var(--text-main);
        }

        .hero .subtitle {
            font-size: 1.3rem;
            color: var(--text-sub);
            margin-bottom: 32px;
            max-width: 550px;
        }

        .hero-buttons {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
        }

        .btn-primary {
            background: var(--accent);
            color: white;
            padding: 14px 32px;
            border-radius: var(--radius-btn);
            font-weight: 600;
            font-size: 1rem;
            border: none;
            display: inline-block;
        }

        .btn-primary:hover {
            background: var(--accent-dark);
            box-shadow: 0 4px 14px rgba(248,92,60,0.4);
            transform: translateY(-2px);
            color: white;
        }

        .btn-secondary {
            background: transparent;
            color: var(--primary);
            border: 2px solid var(--primary);
            padding: 14px 32px;
            border-radius: var(--radius-btn);
            font-weight: 600;
            font-size: 1rem;
        }

        .btn-secondary:hover {
            background: var(--primary);
            color: white;
            border-color: var(--primary);
        }

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

        .section-title {
            text-align: center;
            font-size: 2.2rem;
            font-weight: 600;
            margin-bottom: 50px;
            color: var(--text-main);
        }

        /* 亮点 */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 30px;
        }

        .feature-card {
            background: var(--card-bg);
            padding: 32px 24px;
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-sm);
            text-align: center;
            transition: all 0.25s;
        }

        .feature-card:hover {
            box-shadow: var(--shadow-hover);
            transform: translateY(-4px);
        }

        .feature-card i {
            font-size: 2.4rem;
            color: var(--accent);
            margin-bottom: 18px;
        }

        .feature-card h3 {
            font-size: 1.3rem;
            font-weight: 600;
            margin-bottom: 12px;
        }

        .feature-card p {
            color: var(--text-sub);
            font-size: 0.95rem;
        }

        /* 案例瀑布流 */
        .case-grid {
            column-count: 3;
            column-gap: 24px;
        }

        .case-card {
            background: var(--card-bg);
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-sm);
            margin-bottom: 24px;
            break-inside: avoid;
            transition: all 0.25s;
            overflow: hidden;
        }

        .case-card:hover {
            box-shadow: var(--shadow-hover);
            transform: translateY(-4px);
        }

        .case-card img {
            width: 100%;
            border-radius: 12px 12px 0 0;
            transition: transform 0.3s;
        }

        .case-card:hover img {
            transform: scale(1.03);
        }

        .case-body {
            padding: 18px;
        }

        .case-tag {
            background: rgba(248,92,60,0.1);
            color: var(--accent);
            padding: 2px 12px;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
            display: inline-block;
            margin-bottom: 10px;
        }

        .case-body h4 {
            font-weight: 600;
            margin: 8px 0;
        }

        .case-body p {
            color: var(--text-sub);
            font-size: 0.9rem;
        }

        /* 对比表 */
        .compare-wrapper {
            display: flex;
            gap: 30px;
            max-width: 1000px;
            margin: 0 auto;
        }

        .compare-col {
            flex: 1;
            background: var(--card-bg);
            border-radius: var(--radius-card);
            padding: 28px;
            box-shadow: var(--shadow-sm);
        }

        .compare-col.old {
            background: #F1F5F9;
            color: var(--text-muted);
        }

        .compare-col.new {
            background: #EAF6FA;
            border: 1px solid var(--primary);
        }

        .compare-col h3 {
            font-weight: 700;
            margin-bottom: 24px;
            text-align: center;
        }

        .compare-item {
            display: flex;
            align-items: flex-start;
            gap: 10px;
            margin-bottom: 16px;
            font-size: 0.95rem;
        }

        .compare-item i {
            margin-top: 3px;
            font-size: 1rem;
        }

        .new .compare-item i {
            color: var(--success);
        }

        .old .compare-item i {
            color: var(--text-muted);
        }

        /* FAQ */
        .accordion {
            max-width: 820px;
            margin: 0 auto;
        }

        .accordion-item {
            background: white;
            border-radius: 10px;
            margin-bottom: 12px;
            box-shadow: var(--shadow-sm);
        }

        .accordion-title {
            font-weight: 600;
            padding: 18px 24px;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            color: var(--text-main);
        }

        .accordion-content {
            padding: 0 24px 20px;
            color: var(--text-sub);
            display: none;
        }

        .accordion-item.active .accordion-content {
            display: block;
        }

        /* CTA 横幅 */
        .cta-banner {
            background: var(--dark-bg);
            background-image: radial-gradient(circle at 20% 30%, rgba(255,255,255,0.05) 0%, transparent 40%);
            color: white;
            text-align: center;
            padding: 80px 0;
        }

        .cta-banner h2 {
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 16px;
        }

        .cta-banner p {
            color: #CBD5E1;
            margin-bottom: 32px;
        }

        .btn-glow {
            background: var(--accent);
            color: white;
            padding: 16px 36px;
            border-radius: var(--radius-btn);
            box-shadow: 0 0 20px rgba(248,92,60,0.5);
            font-weight: 700;
            font-size: 1.1rem;
        }

        .btn-glow:hover {
            background: #f97316;
            box-shadow: 0 0 28px rgba(248,92,60,0.75);
            color: white;
        }

        /* 页脚 */
        .site-footer {
            background: var(--dark-bg);
            color: #CBD5E1;
            padding: 60px 0 30px;
        }

        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1.5fr;
            gap: 30px;
        }

        .footer-col h4 {
            color: white;
            font-weight: 600;
            margin-bottom: 18px;
        }

        .footer-col a {
            color: #CBD5E1;
            display: block;
            margin-bottom: 8px;
        }

        .footer-col a:hover {
            color: white;
        }

        .copyright {
            border-top: 1px solid rgba(255,255,255,0.1);
            margin-top: 40px;
            padding-top: 20px;
            text-align: center;
            color: var(--text-muted);
            font-size: 0.9rem;
        }