/* roulang page: index */
:root {
            --primary: #FF5A1F;
            --primary-hover: #E04A10;
            --secondary: #1E1E1E;
            --bg: #F7F7F7;
            --white: #FFFFFF;
            --text: #444444;
            --text-light: #777777;
            --border: #EEEEEE;
            --accent: #00C2BA;
            --radius: 12px;
            --radius-btn: 30px;
            --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
            --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
            --transition: 0.25s ease;
            --font-cn: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
            --font-en: "Inter", "Roboto", system-ui, sans-serif;
            --max-width: 1200px;
            --section-pad: 80px;
        }

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

        body {
            font-family: var(--font-cn);
            font-size: 16px;
            line-height: 1.8;
            color: var(--text);
            background-color: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            overflow-x: hidden;
        }

        h1, h2, h3, h4, h5, h6 {
            font-family: var(--font-cn);
            color: var(--secondary);
            line-height: 1.3;
            margin-bottom: 0.5rem;
        }

        h1 {
            font-size: 36px;
            font-weight: 700;
        }
        h2 {
            font-size: 28px;
            font-weight: 600;
        }
        h3 {
            font-size: 22px;
            font-weight: 600;
        }
        p {
            margin-bottom: 1rem;
            color: var(--text);
        }
        a {
            color: var(--primary);
            text-decoration: none;
            transition: color var(--transition), text-decoration var(--transition);
        }
        a:hover {
            color: var(--primary-hover);
            text-decoration: underline;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }

        /* 导航 */
        .site-header {
            background: var(--white);
            position: sticky;
            top: 0;
            z-index: 100;
            height: 72px;
            border-bottom: 1px solid var(--border);
            transition: box-shadow var(--transition);
            display: flex;
            align-items: center;
        }
        .site-header.scrolled {
            box-shadow: var(--shadow-md);
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
        }
        .logo {
            font-size: 24px;
            font-weight: 700;
            color: var(--secondary);
            display: flex;
            align-items: center;
            gap: 8px;
            text-decoration: none;
        }
        .logo i {
            color: var(--primary);
            font-size: 28px;
        }
        .logo span {
            color: var(--primary);
        }
        .nav-links {
            display: flex;
            align-items: center;
            gap: 32px;
            list-style: none;
            margin: 0;
        }
        .nav-links a {
            color: var(--secondary);
            font-weight: 500;
            font-size: 15px;
            transition: color var(--transition);
            text-decoration: none;
        }
        .nav-links a:hover {
            color: var(--primary);
            text-decoration: none;
        }
        .nav-cta {
            background: var(--primary);
            color: var(--white) !important;
            padding: 10px 24px;
            border-radius: var(--radius-btn);
            font-weight: 600;
            transition: background var(--transition), box-shadow var(--transition);
            text-decoration: none;
            display: inline-block;
        }
        .nav-cta:hover {
            background: var(--primary-hover);
            box-shadow: 0 4px 12px rgba(255,90,31,0.3);
            text-decoration: none;
        }
        .hamburger {
            display: none;
            background: none;
            border: none;
            font-size: 28px;
            color: var(--secondary);
            cursor: pointer;
            padding: 8px;
        }
        @media (max-width: 768px) {
            .nav-links {
                display: none;
                position: fixed;
                top: 72px;
                left: 0;
                width: 100%;
                background: var(--white);
                flex-direction: column;
                padding: 32px 24px;
                box-shadow: var(--shadow-md);
                gap: 24px;
                z-index: 99;
            }
            .nav-links.active {
                display: flex;
            }
            .hamburger {
                display: block;
            }
            .nav-cta.desktop-only {
                display: none;
            }
        }

        /* Hero */
        .hero {
            padding: 100px 0;
            background: var(--white);
            position: relative;
            overflow: hidden;
        }
        .hero-grid {
            display: flex;
            align-items: center;
            gap: 60px;
        }
        .hero-left {
            flex: 1;
            z-index: 2;
        }
        .hero-right {
            flex: 1;
            position: relative;
        }
        .hero-right img {
            border-radius: var(--radius);
            box-shadow: var(--shadow-md);
            transform: rotate(1deg);
            transition: transform 0.3s ease;
            width: 100%;
            object-fit: cover;
            aspect-ratio: 4/3;
        }
        .hero-right img:hover {
            transform: rotate(0deg) scale(1.02);
        }
        .hero h1 {
            margin-bottom: 16px;
        }
        .hero h1 .highlight {
            color: var(--primary);
        }
        .hero p {
            font-size: 18px;
            color: var(--text-light);
            margin-bottom: 32px;
        }
        .btn-group {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
            align-items: center;
        }
        .btn {
            display: inline-block;
            padding: 14px 32px;
            border-radius: var(--radius-btn);
            font-weight: 600;
            font-size: 16px;
            text-decoration: none;
            transition: all var(--transition);
            cursor: pointer;
            border: none;
            text-align: center;
        }
        .btn-primary {
            background: var(--primary);
            color: var(--white);
        }
        .btn-primary:hover {
            background: var(--primary-hover);
            box-shadow: 0 6px 18px rgba(255,90,31,0.25);
            text-decoration: none;
            color: var(--white);
        }
        .btn-outline {
            background: transparent;
            border: 2px solid var(--primary);
            color: var(--primary);
        }
        .btn-outline:hover {
            background: rgba(255,90,31,0.05);
            text-decoration: none;
            color: var(--primary);
        }
        @media (max-width: 768px) {
            .hero {
                padding: 60px 0;
            }
            .hero-grid {
                flex-direction: column;
                gap: 40px;
            }
            .hero-left {
                order: 1;
                text-align: center;
            }
            .hero-right {
                order: 0;
            }
            .hero h1 {
                font-size: 28px;
            }
            .btn-group {
                justify-content: center;
            }
        }

        /* 板块通用 */
        .section {
            padding: var(--section-pad) 0;
        }
        .section-title {
            text-align: center;
            margin-bottom: 48px;
        }
        .section-title h2 {
            margin-bottom: 8px;
        }
        .section-title p {
            color: var(--text-light);
            max-width: 600px;
            margin: 0 auto;
        }
        @media (max-width: 768px) {
            .section {
                padding: 48px 0;
            }
            .section-title {
                margin-bottom: 32px;
            }
        }

        /* 亮点网格 */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .feature-card {
            background: var(--white);
            border-radius: var(--radius);
            padding: 32px 24px;
            text-align: center;
            border: 1px solid var(--border);
            box-shadow: var(--shadow-sm);
            transition: all var(--transition);
        }
        .feature-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-md);
        }
        .feature-icon {
            font-size: 48px;
            color: var(--primary);
            margin-bottom: 16px;
        }
        .feature-card h3 {
            margin-bottom: 8px;
        }
        @media (max-width: 768px) {
            .features-grid {
                grid-template-columns: 1fr 1fr;
            }
        }
        @media (max-width: 520px) {
            .features-grid {
                grid-template-columns: 1fr;
            }
        }

        /* 案例瀑布流 */
        .cases-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 24px;
        }
        .case-card {
            background: var(--white);
            border-radius: var(--radius);
            overflow: hidden;
            border: 1px solid var(--border);
            box-shadow: var(--shadow-sm);
            transition: all var(--transition);
            display: flex;
            flex-direction: column;
        }
        .case-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-md);
        }
        .case-img {
            height: 220px;
            overflow: hidden;
        }
        .case-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.4s ease;
        }
        .case-card:hover .case-img img {
            transform: scale(1.05);
        }
        .case-body {
            padding: 20px;
            flex: 1;
        }
        .case-tags {
            display: flex;
            gap: 8px;
            flex-wrap: wrap;
            margin-bottom: 8px;
        }
        .tag {
            background: rgba(0,194,186,0.1);
            color: var(--accent);
            font-size: 12px;
            padding: 4px 12px;
            border-radius: 20px;
            font-weight: 500;
        }
        .case-body h3 {
            font-size: 18px;
            margin-bottom: 6px;
        }
        @media (max-width: 768px) {
            .cases-grid {
                grid-template-columns: 1fr;
            }
        }

        /* 方案对比 */
        .plans-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
            align-items: start;
        }
        .plan-card {
            background: var(--white);
            border-radius: var(--radius);
            border: 1px solid var(--border);
            overflow: hidden;
            box-shadow: var(--shadow-sm);
            transition: all var(--transition);
            position: relative;
        }
        .plan-card.featured {
            background: var(--primary);
            color: var(--white);
            border-color: var(--primary);
            transform: scale(1.02);
        }
        .plan-card.featured h3,
        .plan-card.featured .plan-price,
        .plan-card.featured ul li {
            color: var(--white);
        }
        .plan-card.featured .btn-outline {
            border-color: var(--white);
            color: var(--white);
        }
        .plan-card.featured .btn-outline:hover {
            background: rgba(255,255,255,0.15);
        }
        .plan-header {
            padding: 24px;
            border-bottom: 1px solid var(--border);
        }
        .plan-card.featured .plan-header {
            border-bottom-color: rgba(255,255,255,0.2);
        }
        .plan-body {
            padding: 24px;
        }
        .plan-body ul {
            list-style: none;
            margin: 0 0 20px;
            padding: 0;
        }
        .plan-body ul li {
            padding: 6px 0;
            color: var(--text);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .plan-body ul li i {
            color: var(--accent);
        }
        .plan-card.featured .plan-body ul li i {
            color: var(--white);
        }
        .plan-price {
            font-size: 32px;
            font-weight: 700;
            color: var(--secondary);
            margin: 8px 0;
        }
        .btn-block {
            display: block;
            width: 100%;
            text-align: center;
        }
        @media (max-width: 768px) {
            .plans-grid {
                grid-template-columns: 1fr;
            }
            .plan-card.featured {
                transform: none;
            }
        }

        /* CTA 色块 */
        .cta-section {
            background: linear-gradient(135deg, #FF5A1F 0%, #E04A10 100%);
            color: var(--white);
            padding: 80px 0;
            text-align: center;
        }
        .cta-section h2,
        .cta-section p {
            color: var(--white);
        }
        .cta-form {
            max-width: 600px;
            margin: 32px auto 0;
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 16px;
        }
        .cta-form .full-width {
            grid-column: span 2;
        }
        .cta-form input,
        .cta-form textarea {
            width: 100%;
            background: rgba(255,255,255,0.15);
            border: none;
            border-bottom: 2px solid rgba(255,255,255,0.5);
            padding: 12px 8px;
            color: var(--white);
            font-size: 16px;
            outline: none;
            transition: border-color 0.2s;
            border-radius: 0;
        }
        .cta-form input::placeholder,
        .cta-form textarea::placeholder {
            color: rgba(255,255,255,0.7);
        }
        .cta-form input:focus,
        .cta-form textarea:focus {
            border-bottom-color: var(--white);
        }
        .cta-form .btn-white {
            background: var(--white);
            color: var(--primary);
            font-weight: 600;
            padding: 14px 32px;
            border-radius: var(--radius-btn);
            border: none;
            cursor: pointer;
            transition: all var(--transition);
            grid-column: span 2;
            justify-self: center;
            min-width: 200px;
        }
        .cta-form .btn-white:hover {
            background: #f0f0f0;
            box-shadow: 0 6px 18px rgba(0,0,0,0.15);
        }
        @media (max-width: 768px) {
            .cta-form {
                grid-template-columns: 1fr;
            }
            .cta-form .full-width,
            .cta-form .btn-white {
                grid-column: span 1;
            }
        }

        /* FAQ */
        .faq-list {
            max-width: 800px;
            margin: 0 auto;
        }
        .faq-item {
            border-bottom: 1px solid var(--border);
            padding: 16px 0;
            cursor: pointer;
        }
        .faq-question {
            font-weight: 600;
            font-size: 18px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            color: var(--secondary);
        }
        .faq-question i {
            transition: transform 0.3s ease;
            color: var(--primary);
        }
        .faq-item.open .faq-question i {
            transform: rotate(45deg);
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease, padding 0.3s ease;
            background: #FAFAFA;
            border-radius: 8px;
            margin-top: 8px;
        }
        .faq-item.open .faq-answer {
            max-height: 200px;
            padding: 16px;
        }
        .faq-answer p {
            margin: 0;
            color: var(--text);
        }

        /* 页脚 */
        .site-footer {
            background: var(--secondary);
            color: #CCCCCC;
            padding: 60px 0 24px;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 40px;
        }
        .footer-col h4 {
            color: var(--white);
            margin-bottom: 16px;
            font-size: 16px;
        }
        .footer-col ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }
        .footer-col ul li {
            margin-bottom: 8px;
        }
        .footer-col a {
            color: #CCCCCC;
            text-decoration: none;
            transition: color var(--transition);
        }
        .footer-col a:hover {
            color: var(--white);
            text-decoration: none;
        }
        .footer-logo {
            font-size: 24px;
            font-weight: 700;
            color: var(--white);
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .social-icons {
            display: flex;
            gap: 16px;
            margin-top: 16px;
        }
        .social-icons a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background: rgba(255,255,255,0.1);
            color: #CCCCCC;
            font-size: 18px;
            transition: all var(--transition);
        }
        .social-icons a:hover {
            background: var(--primary);
            color: var(--white);
            text-decoration: none;
        }
        .copyright {
            border-top: 1px solid rgba(255,255,255,0.1);
            padding-top: 24px;
            text-align: center;
            font-size: 14px;
        }
        @media (max-width: 768px) {
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 32px;
            }
        }
        @media (max-width: 520px) {
            .footer-grid {
                grid-template-columns: 1fr;
            }
        }

        /* 装饰速度线 */
        .speed-line {
            position: absolute;
            height: 3px;
            background: var(--primary);
            opacity: 0.2;
            width: 120px;
            transform: skewX(-25deg);
        }