/* roulang page: index */
:root {
            --color-primary: #168786;
            --color-primary-hover: #0F6B6A;
            --color-primary-light: #E0F2F1;
            --color-accent: #F4735A;
            --color-accent-hover: #E55D3A;
            --color-bg-body: #FCFDFD;
            --color-bg-section: #F3F6F6;
            --color-text-primary: #1A2C38;
            --color-text-secondary: #5A6B77;
            --color-text-inverse: #FFFFFF;
            --color-card-bg: #FFFFFF;
            --color-card-shadow: rgba(22, 135, 134, 0.06);
            --color-border: #E8EDED;
            --color-footer-bg: #1A2C38;
        }

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

        html {
            scroll-behavior: smooth;
            scroll-padding-top: 76px;
        }

        body {
            margin: 0;
            padding: 0;
            font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
            font-size: 1rem;
            line-height: 1.7;
            color: var(--color-text-primary);
            background-color: var(--color-bg-body);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        a {
            color: inherit;
            text-decoration: none;
            transition: color 0.15s ease;
        }
        a:hover {
            color: var(--color-primary);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        button {
            cursor: pointer;
            font-family: inherit;
            border: none;
            outline: none;
        }
        button:focus-visible,
        a:focus-visible {
            outline: 2px solid var(--color-primary);
            outline-offset: 2px;
            border-radius: 4px;
        }
        input:focus-visible {
            outline: none;
            border-color: var(--color-primary) !important;
            box-shadow: 0 0 0 3px var(--color-primary-light) !important;
        }

        /* 导航 */
        .site-nav {
            position: sticky;
            top: 0;
            z-index: 50;
            background: #FFFFFF;
            height: 68px;
            box-shadow: 0 1px 0 var(--color-border);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            background: rgba(255, 255, 255, 0.97);
        }
        .nav-link {
            position: relative;
            font-size: 0.9375rem;
            font-weight: 500;
            color: var(--color-text-secondary);
            padding: 0.35rem 0;
            transition: color 0.2s ease;
            white-space: nowrap;
        }
        .nav-link:hover {
            color: var(--color-primary);
        }
        .nav-link.active {
            color: var(--color-primary);
        }
        .nav-link.active::after {
            content: '';
            position: absolute;
            bottom: -4px;
            left: 0;
            right: 0;
            height: 2px;
            background: var(--color-primary);
            border-radius: 2px;
        }

        /* 汉堡菜单 */
        .hamburger-line {
            display: block;
            width: 24px;
            height: 2px;
            background: var(--color-text-primary);
            border-radius: 2px;
            transition: all 0.3s ease;
            margin: 5px 0;
        }
        .hamburger-open .hamburger-line:nth-child(1) {
            transform: translateY(7px) rotate(45deg);
        }
        .hamburger-open .hamburger-line:nth-child(2) {
            opacity: 0;
        }
        .hamburger-open .hamburger-line:nth-child(3) {
            transform: translateY(-7px) rotate(-45deg);
        }
        .off-canvas {
            position: fixed;
            top: 0;
            right: -100%;
            width: 75vw;
            max-width: 360px;
            height: 100vh;
            background: #FFFFFF;
            z-index: 60;
            padding: 2rem 1.5rem;
            transition: right 0.35s cubic-bezier(0.4, 0, 0.2, 1);
            box-shadow: -4px 0 24px rgba(0, 0, 0, 0.12);
            overflow-y: auto;
        }
        .off-canvas.open {
            right: 0;
        }
        .off-canvas-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.4);
            z-index: 55;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.35s ease;
        }
        .off-canvas-overlay.show {
            opacity: 1;
            pointer-events: auto;
        }

        /* Hero遮罩 */
        .hero-bg-mask {
            position: relative;
        }
        @media (max-width: 767px) {
            .hero-bg-mask::before {
                content: '';
                position: absolute;
                inset: 0;
                background: linear-gradient(180deg, rgba(252, 253, 253, 0.75) 0%, rgba(252, 253, 253, 0.88) 50%, rgba(252, 253, 253, 0.96) 100%);
                z-index: 1;
                pointer-events: none;
                border-radius: inherit;
            }
            .hero-bg-mask>* {
                position: relative;
                z-index: 2;
            }
        }

        /* 卡片hover */
        .card-hover {
            transition: transform 0.25s ease, box-shadow 0.25s ease;
            border: 1px solid var(--color-border);
            border-radius: 14px;
            background: var(--color-card-bg);
            box-shadow: 0 2px 12px var(--color-card-shadow);
        }
        .card-hover:hover {
            transform: translateY(-4px);
            box-shadow: 0 8px 28px rgba(22, 135, 134, 0.10);
        }

        /* 案例横滚 */
        .cases-scroll {
            display: flex;
            gap: 1.25rem;
            overflow-x: auto;
            scroll-snap-type: x mandatory;
            -webkit-overflow-scrolling: touch;
            scrollbar-width: none;
            padding-bottom: 0.5rem;
        }
        .cases-scroll::-webkit-scrollbar {
            display: none;
        }
        .cases-scroll>* {
            scroll-snap-align: start;
            flex-shrink: 0;
        }
        @media (max-width: 767px) {
            .cases-scroll {
                flex-direction: column;
                overflow-x: visible;
                scroll-snap-type: none;
                gap: 1rem;
            }
            .cases-scroll>* {
                scroll-snap-align: none;
                flex-shrink: 1;
                width: 100%;
            }
        }

        /* 手风琴 */
        .faq-item {
            border-bottom: 1px solid var(--color-border);
        }
        .faq-question {
            width: 100%;
            background: none;
            border: none;
            padding: 1.1rem 0;
            display: flex;
            justify-content: space-between;
            align-items: center;
            text-align: left;
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--color-text-primary);
            cursor: pointer;
            gap: 1rem;
        }
        .faq-question:hover {
            color: var(--color-primary);
        }
        .faq-icon {
            flex-shrink: 0;
            width: 28px;
            height: 28px;
            border-radius: 50%;
            border: 1.5px solid var(--color-primary);
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s ease;
            color: var(--color-primary);
            font-size: 1.2rem;
            line-height: 1;
            font-weight: 500;
        }
        .faq-item.open .faq-icon {
            background: var(--color-primary);
            color: #fff;
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.4s ease, padding 0.4s ease;
            color: var(--color-text-secondary);
            line-height: 1.75;
            font-size: 0.95rem;
        }
        .faq-item.open .faq-answer {
            max-height: 300px;
            padding-bottom: 1rem;
        }

        /* 按钮系统 */
        .btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: var(--color-accent);
            color: #FFFFFF;
            font-weight: 600;
            letter-spacing: 0.01em;
            font-size: 0.9375rem;
            padding: 0.75rem 2rem;
            border-radius: 10px;
            border: none;
            cursor: pointer;
            transition: all 0.2s ease;
            text-decoration: none;
            white-space: nowrap;
        }
        .btn-primary:hover {
            background: var(--color-accent-hover);
            transform: translateY(-1px);
            box-shadow: 0 6px 20px rgba(244, 115, 90, 0.3);
            color: #FFFFFF;
        }
        .btn-secondary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: transparent;
            color: var(--color-primary);
            font-weight: 600;
            letter-spacing: 0.01em;
            font-size: 0.9375rem;
            padding: 0.7rem 1.85rem;
            border-radius: 10px;
            border: 2px solid var(--color-primary);
            cursor: pointer;
            transition: all 0.2s ease;
            text-decoration: none;
            white-space: nowrap;
        }
        .btn-secondary:hover {
            background: var(--color-primary-light);
            border-color: var(--color-primary-hover);
            color: var(--color-primary-hover);
        }
        .btn-white {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: #FFFFFF;
            color: var(--color-primary);
            font-weight: 600;
            letter-spacing: 0.01em;
            font-size: 1rem;
            padding: 0.8rem 2.2rem;
            border-radius: 10px;
            border: none;
            cursor: pointer;
            transition: all 0.2s ease;
            text-decoration: none;
            white-space: nowrap;
        }
        .btn-white:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
            color: var(--color-primary-hover);
        }
        .btn-nav-cta {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: var(--color-accent);
            color: #FFFFFF;
            font-weight: 600;
            font-size: 0.875rem;
            padding: 0.5rem 1.25rem;
            border-radius: 8px;
            border: none;
            cursor: pointer;
            transition: all 0.2s ease;
            text-decoration: none;
            white-space: nowrap;
        }
        .btn-nav-cta:hover {
            background: var(--color-accent-hover);
            transform: translateY(-1px);
            box-shadow: 0 4px 14px rgba(244, 115, 90, 0.25);
            color: #FFFFFF;
        }

        /* 案例箭头 */
        .case-arrow {
            width: 42px;
            height: 42px;
            border-radius: 50%;
            background: #FFFFFF;
            border: 1.5px solid var(--color-border);
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: all 0.2s ease;
            color: var(--color-text-primary);
            font-size: 1.1rem;
            flex-shrink: 0;
        }
        .case-arrow:hover {
            background: var(--color-primary-light);
            border-color: var(--color-primary);
            color: var(--color-primary);
        }

        /* 页脚 */
        .footer-link {
            color: #A8B8C0;
            transition: color 0.2s ease;
            font-size: 0.9rem;
        }
        .footer-link:hover {
            color: #FFFFFF;
        }

        /* 响应式容器 */
        .container-custom {
            max-width: 1200px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 1.5rem;
            padding-right: 1.5rem;
        }
        @media (max-width: 640px) {
            .container-custom {
                padding-left: 1rem;
                padding-right: 1rem;
            }
        }

        /* 数字字体 */
        .font-numeral {
            font-family: 'Inter', 'SF Pro Display', -apple-system, sans-serif;
        }

        /* 图文交替区块图片 */
        .solution-img {
            border-radius: 12px;
            width: 100%;
            height: auto;
            object-fit: cover;
            aspect-ratio: 4/3;
        }