/* ……样式与原文一致，此处省略，保留完整CSS…… */
        :root {
            --primary-color: #1A56DB;
            --secondary-color: #1E40AF;
            --bg-color: #F9FAFB;
            --text-main: #111827;
            --text-muted: #4B5563;
            --white: #FFFFFF;
            --border-color: #E5E7EB;
            --section-spacing: 80px;
            --inner-spacing: 32px;
            --grid-gap: 24px;
            --header-height: 72px;
            --border-radius: 8px;
            --transition: all 0.3s ease;
        }
        * { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; scroll-padding-top: var(--header-height); }
        body {
            font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
            color: var(--text-main);
            background-color: var(--bg-color);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
            word-wrap: break-word;
            overflow-wrap: break-word;
            font-size: 16px; /* 【优化11】移动端最小字号保障 */
        }
        .en-text { font-family: "Helvetica Neue", Arial, sans-serif; letter-spacing: 0.5px; }
        a { text-decoration: none; color: inherit; }
        ul { list-style: none; }
        img { max-width: 100%; height: auto; display: block; }

        h1,h2,h3,h4,h5,h6 { font-weight: 700; line-height: 1.3; color: var(--text-main); }
        h1 { font-size: 2.5rem; margin-bottom: 1.5rem; }
        h2 { font-size: 2rem; margin-bottom: 3rem; text-align: center; }
        h3 { font-size: 1.25rem; margin-bottom: 1rem; }
        p { margin-bottom: 1rem; color: var(--text-muted); }

        .container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; }
        section { padding: var(--section-spacing) 0; }

        /* 【优化12】面包屑样式 */
        .breadcrumb { padding: 12px 0; font-size: .875rem; color: var(--text-muted); }
        .breadcrumb ol { display: flex; gap: 8px; list-style: none; flex-wrap: wrap; }
        .breadcrumb li+li::before { content: "›"; margin-right: 8px; color: #9CA3AF; }
        .breadcrumb a { color: var(--text-muted); }
        .breadcrumb a:hover { color: var(--primary-color); }

        .btn { display: inline-flex; align-items: center; justify-content: center; padding: 12px 28px; font-size: 1rem; font-weight: 600; border-radius: var(--border-radius); cursor: pointer; transition: var(--transition); border: none; text-align: center; }
        .btn-primary { background-color: var(--primary-color); color: var(--white); }
        .btn-primary:hover { background-color: var(--secondary-color); transform: translateY(-2px); box-shadow: 0 4px 12px rgba(26,86,219,.3); }

        .placeholder-img { background-color: #E5E7EB; border-radius: var(--border-radius); display: flex; align-items: center; justify-content: center; color: var(--text-muted); font-weight: 600; width: 100%; min-height: 300px; border: 2px dashed #D1D5DB; }

        header { position: fixed; top: 0; left: 0; width: 100%; height: var(--header-height); background-color: rgba(255,255,255,.95); backdrop-filter: blur(8px); z-index: 1000; transition: var(--transition); border-bottom: 1px solid transparent; }
        header.scrolled { box-shadow: 0 4px 6px -1px rgba(0,0,0,.1); border-bottom-color: var(--border-color); }
        .nav-container { display: flex; justify-content: space-between; align-items: center; height: 100%; }
        .logo { font-size: 1.5rem; font-weight: 700; color: var(--primary-color); display: flex; align-items: center; gap: 8px; }
        .nav-links { display: flex; gap: 32px; }
        .nav-links a { font-weight: 500; color: var(--text-muted); transition: var(--transition); }
        .nav-links a:hover { color: var(--primary-color); }

        /* 【优化13】移动端汉堡菜单 */
        .nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
        .nav-toggle span { display: block; width: 24px; height: 2px; background: var(--text-main); margin: 5px 0; transition: var(--transition); }
        @media (max-width: 767px) {
            .nav-toggle { display: block; }
            .nav-links {
                position: fixed; top: var(--header-height); left: 0; right: 0;
                background: var(--white); flex-direction: column; gap: 0;
                padding: 16px 24px; box-shadow: 0 8px 16px rgba(0,0,0,.1);
                transform: translateY(-120%); transition: transform .3s ease;
            }
            .nav-links.open { transform: translateY(0); }
            .nav-links a { padding: 12px 0; border-bottom: 1px solid var(--border-color); }
        }

        #hero { padding-top: calc(var(--section-spacing) + var(--header-height)); background: linear-gradient(135deg,#F9FAFB 0%,#EBF0FF 100%); }
        .hero-content { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
        .hero-text .subtitle { font-size: 1.25rem; color: var(--primary-color); font-weight: 600; margin-bottom: 1rem; display: block; }
        .hero-features { margin: 24px 0 32px; }
        .hero-features li { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; font-size: 1.1rem; color: var(--text-main); }
        .hero-features svg { width: 24px; height: 24px; fill: var(--primary-color); }

        #pain-points { background-color: var(--white); }
        .pain-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: var(--grid-gap); }
        .pain-card { background-color: var(--bg-color); padding: var(--inner-spacing); border-radius: var(--border-radius); border: 1px solid var(--border-color); text-align: center; transition: var(--transition); }
        .pain-card:hover { transform: translateY(-5px); box-shadow: 0 10px 15px -3px rgba(0,0,0,.1); }
        .pain-icon { width: 48px; height: 48px; margin: 0 auto 16px; color: #EF4444; }

        .solution-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: var(--grid-gap); }
        .solution-card { background-color: var(--white); padding: var(--inner-spacing); border-radius: var(--border-radius); box-shadow: 0 4px 6px -1px rgba(0,0,0,.05); border: 1px solid var(--border-color); }
        .solution-icon { width: 40px; height: 40px; color: var(--primary-color); margin-bottom: 16px; }

        #trust { background-color: var(--white); }
        .trust-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: var(--grid-gap); text-align: center; }
        .trust-item h3 { font-size: 2.5rem; color: var(--primary-color); margin-bottom: 8px; }

        .keywords-grid { display: grid; grid-template-columns: repeat(auto-fill,minmax(250px,1fr)); gap: 16px; }
        .keyword-card { background-color: var(--white); padding: 20px; border-radius: var(--border-radius); border: 1px solid var(--border-color); }
        .keyword-card h3 { font-size: 1.1rem; margin-bottom: 8px; color: var(--secondary-color); }
        .keyword-card p { font-size: .9rem; margin-bottom: 0; }

        #faq { background-color: var(--white); }
        .faq-container { max-width: 800px; margin: 0 auto; }
        .faq-item { border: 1px solid var(--border-color); border-radius: var(--border-radius); margin-bottom: 12px; overflow: hidden; }
        /* 【优化14】FAQ 问题用 h3 语义化 + button 结构 */
        .faq-question { width: 100%; padding: 20px 24px; background-color: var(--bg-color); cursor: pointer; display: flex; justify-content: space-between; align-items: center; font-weight: 600; font-size: 1rem; border: none; text-align: left; transition: var(--transition); font-family: inherit; color: var(--text-main); }
        .faq-question:hover { background-color: #F3F4F6; }
        .faq-icon { width: 20px; height: 20px; transition: transform .3s ease; flex-shrink: 0; }
        .faq-item.active .faq-icon { transform: rotate(180deg); }
        /* 【优化15】改用 grid 动画避免 CLS */
        .faq-answer { display: grid; grid-template-rows: 0fr; transition: grid-template-rows .3s ease-out; background-color: var(--white); }
        .faq-item.active .faq-answer { grid-template-rows: 1fr; }
        .faq-answer-inner { overflow: hidden; padding: 0 24px; border-top: 1px solid var(--border-color); color: var(--text-muted); }
        .faq-item.active .faq-answer-inner { padding: 20px 24px; }

        #contact { background-color: var(--primary-color); color: var(--white); }
        #contact h2, #contact p { color: var(--white); }
        .contact-wrapper { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
        .contact-form { background-color: var(--white); padding: var(--inner-spacing); border-radius: var(--border-radius); color: var(--text-main); }
        .form-group { margin-bottom: 20px; }
        .form-group label { display: block; margin-bottom: 8px; font-weight: 500; }
        .form-control { width: 100%; padding: 12px 16px; border: 1px solid var(--border-color); border-radius: 4px; font-family: inherit; font-size: 1rem; transition: var(--transition); }
        .form-control:focus { outline: none; border-color: var(--primary-color); box-shadow: 0 0 0 3px rgba(26,86,219,.1); }
        textarea.form-control { resize: vertical; min-height: 100px; }
        .form-submit { width: 100%; font-size: 1.1rem; }
        .error-msg { color: #EF4444; font-size: .875rem; margin-top: 4px; display: none; }

        footer { background-color: var(--text-main); color: #9CA3AF; padding: 48px 0 24px; text-align: center; }
        .footer-content { margin-bottom: 24px; }
        .footer-content p { color: #9CA3AF; margin-bottom: 8px; }
        /* 【优化16】页脚内链聚合 */
        .footer-links { display: flex; justify-content: center; flex-wrap: wrap; gap: 16px; margin: 24px 0; font-size: .875rem; }
        .footer-links a { color: #9CA3AF; }
        .footer-links a:hover { color: var(--white); }

        /* 【优化17】移动端悬浮客服按钮 */
        .float-cta { position: fixed; right: 16px; bottom: 16px; z-index: 999; background: var(--primary-color); color: var(--white); padding: 12px 20px; border-radius: 32px; box-shadow: 0 8px 20px rgba(26,86,219,.4); font-weight: 600; display: flex; align-items: center; gap: 6px; }
        .float-cta:hover { background: var(--secondary-color); }

        @media (max-width: 1024px) {
            .hero-content, .contact-wrapper { grid-template-columns: 1fr; text-align: center; }
            .hero-features li { justify-content: center; }
            .solution-grid, .trust-grid { grid-template-columns: repeat(2,1fr); }
        }
        @media (max-width: 767px) {
            :root { --section-spacing: 48px; --inner-spacing: 24px; }
            h1 { font-size: 2rem; }
            h2 { font-size: 1.5rem; margin-bottom: 2rem; }
            .pain-grid, .solution-grid, .trust-grid { grid-template-columns: 1fr; }
            .keywords-grid { grid-template-columns: 1fr; }
        }