/* Global & CSS Variables */
        :root {
            --primary: #4F46E5; 
            --primary-dark: #3730A3;
            --secondary: #9333EA; 
            --accent: #F97316; 
            --text-main: #0F172A;
            --text-light: #475569;
            --bg-white: #FFFFFF;
            --bg-offwhite: #F8FAFC;
            --glass-bg: rgba(255, 255, 255, 0.85);
            --glass-border: rgba(255, 255, 255, 0.9);
            --shadow-soft: 0 10px 40px -10px rgba(79, 70, 229, 0.12);
            --shadow-hover: 0 20px 40px -10px rgba(147, 51, 234, 0.2);
            --radius-xl: 32px;
            --radius-lg: 24px;
            --radius-md: 16px;
        }

        /* 基础重置与防溢出 */
        * { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Plus Jakarta Sans', sans-serif; }
        html { scroll-behavior: smooth; }
        body { background-color: var(--bg-white); color: var(--text-main); line-height: 1.8; }
        html, body { width: 100%; max-width: 100%; overflow-x: hidden !important; position: relative; }

        /* Dynamic Background Orbs */
        .bg-orb { position: absolute; border-radius: 50%; filter: blur(140px); z-index: -1; opacity: 0.35; animation: float 12s infinite ease-in-out alternate; }
        .orb-1 { top: -5%; left: -10%; width: 600px; height: 600px; background: var(--secondary); }
        .orb-2 { top: 15%; right: -5%; width: 700px; height: 700px; background: var(--primary); animation-delay: 2s; }
        .orb-3 { top: 40%; left: 15%; width: 500px; height: 500px; background: var(--accent); opacity: 0.15; animation-delay: 4s; }
        .orb-4 { top: 70%; right: 10%; width: 600px; height: 600px; background: var(--primary); opacity: 0.2; }

        @keyframes float { 0% { transform: translate(0, 0) scale(1); } 100% { transform: translate(40px, 60px) scale(1.05); } }

        /* Reusable UI Components */
        .glass-card { background: var(--glass-bg); backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px); border: 1px solid var(--glass-border); border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1); }
        .glass-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }
        
        h1, h2, h3, h4, h5 { color: var(--text-main); letter-spacing: -0.02em; font-weight: 800; line-height: 1.3; }
        .text-gradient { background: linear-gradient(135deg, var(--primary), var(--secondary), var(--accent)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
        
        .badge { display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px; border-radius: 30px; font-size: 0.85rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; }
        .badge-purple { background: rgba(147, 51, 234, 0.1); color: var(--secondary); border: 1px solid rgba(147, 51, 234, 0.2); }
        .badge-orange { background: rgba(249, 115, 22, 0.1); color: var(--accent); border: 1px solid rgba(249, 115, 22, 0.2); }
        .badge-blue { background: rgba(79, 70, 229, 0.1); color: var(--primary); border: 1px solid rgba(79, 70, 229, 0.2); }

        .btn { display: inline-flex; align-items: center; justify-content: center; padding: 18px 36px; border-radius: 50px; font-weight: 700; font-size: 1.1rem; text-decoration: none; transition: all 0.3s ease; border: none; cursor: pointer; position: relative; overflow: hidden; }
        .btn-primary { background: linear-gradient(135deg, var(--primary), var(--secondary)); color: white; box-shadow: 0 10px 25px rgba(79, 70, 229, 0.35); }
        .btn-primary::after { content: ''; position: absolute; top: 0; left: -100%; width: 100%; height: 100%; background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent); transition: all 0.6s ease; }
        .btn-primary:hover::after { left: 100%; }
        .btn-primary:hover { box-shadow: 0 15px 35px rgba(147, 51, 234, 0.45); transform: scale(1.02); }

        .image-rich { width: 100%; height: auto; border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); object-fit: cover; }
        
        .container { max-width: 1280px; margin: 0 auto; padding: 0 24px; z-index: 2; box-sizing: border-box; }
        section { padding: 100px 0; }

        /* Navigation */
        nav { padding: 24px 0; position: sticky; top: 0; z-index: 100; backdrop-filter: blur(20px); background: rgba(255,255,255,0.8); border-bottom: 1px solid rgba(255,255,255,0.5); }
        .nav-inner { display: flex; justify-content: space-between; align-items: center; }
        .logo { color: var(--text-main); text-decoration: none; display: flex; align-items: center; gap: 8px; }
        
        /* Layout Grids */
        .grid-12 { display: grid; grid-template-columns: repeat(12, 1fr); gap: 32px; align-items: center; }
        .col-4 { grid-column: span 4; }
        .col-5 { grid-column: span 5; }
        .col-6 { grid-column: span 6; }
        .col-7 { grid-column: span 7; }
        .col-12 { grid-column: span 12; }

        /* Deep Content Scannable Layout */
        .content-pro { font-size: 1.15rem; color: var(--text-light); margin-bottom: 24px; }
        .content-pro strong { color: var(--text-main); font-weight: 700; }
        .icon-list { list-style: none; margin-top: 24px; }
        .icon-list li { display: flex; align-items: flex-start; gap: 16px; margin-bottom: 20px; font-size: 1.1rem; color: var(--text-main); }
        .icon-list .icon-wrap { flex-shrink: 0; width: 32px; height: 32px; border-radius: 8px; background: rgba(79, 70, 229, 0.1); color: var(--primary); display: flex; align-items: center; justify-content: center; font-size: 14px; margin-top: 4px; }

       
        /* Hero Section */
        .hero { 
            display: flex; 
            flex-direction: column; 
            align-items: center; 
            text-align: center; 
            padding: 60px 0 100px; 
            position: relative; /* 必须加这句：锁住背景图层，不让它跑出首屏范围 */
        }
        

        /* --- 新增：美国地标（曼哈顿天际线）强制全屏透明图层 --- */
        .hero::before {
            content: '';
            position: absolute;
            top: -40px; /* 稍微往上延伸一点，填满内边距的空隙 */
            
            /* --- 核心破壁代码：强行左右铺满屏幕 --- */
            left: 50%;
            transform: translateX(-50%);
            width: 100vw; 
            /* ------------------------------------- */

            height: 110%; /* 覆盖整个首屏高度 */
            background-image: url('../images/manhadun.jpg');
            background-size: cover;
            background-position: center 20%;
            opacity: 0.3; /* 淡淡的高级感水印 */
            z-index: -1;
            pointer-events: none;
            
            /* 边缘羽化遮罩：自然融入纯白背景 */
            -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,1) 0%, rgba(0,0,0,0) 95%);
            mask-image: linear-gradient(to bottom, rgba(0,0,0,1) 0%, rgba(0,0,0,0) 95%);
        }
        .hero-text-box { max-width: 900px; margin-bottom: 60px; }
        .hero h1 { font-size: 4.5rem; line-height: 1.15; margin: 24px 0; }
        .hero p.lead { font-size: 1.3rem; color: var(--text-light); margin-bottom: 40px; font-weight: 500; padding: 0 40px; }
        
        .hero-visual { width: 100%; border-radius: var(--radius-xl); overflow: hidden; position: relative; box-shadow: 0 40px 80px -20px rgba(0,0,0,0.15); border: 8px solid white; }
        .hero-visual img { width: 100%; height: 550px; object-fit: cover; display: block; }
        .hero-floating-card { position: absolute; bottom: 40px; left: 40px; background: rgba(255,255,255,0.95); backdrop-filter: blur(10px); padding: 24px; border-radius: var(--radius-md); box-shadow: 0 20px 40px rgba(0,0,0,0.1); border: 1px solid rgba(255,255,255,0.5); display: flex; align-items: center; gap: 20px; }
        .hero-floating-card .icon { font-size: 2rem; color: #10B981; }

        /* --- Floating Collapsible TOC (Bottom Left) --- */
        .floating-toc-container {
            position: fixed;
            bottom: 40px;
            left: 40px; 
            z-index: 99999;
            display: flex;
            flex-direction: column;
            align-items: flex-start;
            gap: 16px;
            /* 开启硬件加速，防止 Safari 移动端滚动时组件闪烁消失 */
            transform: translateZ(0); 
            -webkit-transform: translateZ(0);
        }

        .toc-toggle-btn {
            height: 50px;
            padding: 0 24px; 
            border-radius: 30px; 
            background: linear-gradient(135deg, var(--secondary), #7e22ce);
            color: white;
            border: none;
            box-shadow: 0 10px 25px rgba(147, 51, 234, 0.4);
            cursor: pointer;
            font-size: 1rem;
            font-weight: 600;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }
        .toc-toggle-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 15px 35px rgba(147, 51, 234, 0.5);
        }

        .toc-menu {
            width: 260px;
            padding: 20px 5px 20px 20px;
            background: var(--glass-bg);
            backdrop-filter: blur(24px);
            -webkit-backdrop-filter: blur(24px);
            border: 1px solid var(--glass-border);
            border-radius: var(--radius-md);
            box-shadow: var(--shadow-hover);
            opacity: 0;
            visibility: hidden;
            transform: translateY(20px) scale(0.95);
            transform-origin: bottom left;
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .floating-toc-container.open .toc-menu {
            opacity: 1;
            visibility: visible;
            transform: translateY(0) scale(1);
        }

        .toc-header { font-size: 0.95rem; font-weight: 800; color: var(--secondary); margin-bottom: 16px; display: flex; align-items: center; gap: 8px; text-transform: uppercase; letter-spacing: 0.5px; }
        
        .toc-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; border-left: 2px solid #E2E8F0; padding-left: 16px; max-height: 40vh; overflow-y: auto; padding-right: 15px; scroll-behavior: smooth; }
        .toc-list::-webkit-scrollbar { width: 4px; }
        .toc-list::-webkit-scrollbar-track { background: rgba(0,0,0,0.03); border-radius: 10px; }
        .toc-list::-webkit-scrollbar-thumb { background: rgba(147, 51, 234, 0.3); border-radius: 10px; }
        .toc-list::-webkit-scrollbar-thumb:hover { background: rgba(147, 51, 234, 0.6); }

        .toc-list a { text-decoration: none; color: var(--text-light); font-size: 0.9rem; font-weight: 500; transition: all 0.3s ease; display: flex; align-items: center; position: relative; padding: 4px 0; }
        .toc-list a.active, .toc-list a:hover { color: var(--secondary); font-weight: 700; }
        .toc-list a::before { content: ''; position: absolute; left: -21px; top: 50%; transform: translateY(-50%) scale(0); width: 10px; height: 10px; background-color: var(--secondary); border-radius: 50%; transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275); box-shadow: 0 0 8px rgba(147, 51, 234, 0.4); }
        .toc-list a.active::before { transform: translateY(-50%) scale(1); }


        /* =========================================================
           移动端统一响应式适配 (Clean Media Queries)
           ========================================================= */

        @media (max-width: 1200px) {
            /* 适配移动端悬浮目录，防刘海屏底部遮挡 */
            .floating-toc-container {
                bottom: max(20px, env(safe-area-inset-bottom));
                left: 20px;
            }
            .toc-toggle-btn { height: 44px; padding: 0 16px; font-size: 0.9rem; }
            .toc-menu { width: calc(100vw - 40px); max-width: 260px; }
        }

        @media (max-width: 1024px) {
            .hero h1 { font-size: 3.5rem; }
            .col-4, .col-5, .col-6, .col-7 { grid-column: span 12; }
            .hero-visual img { height: 400px; }
            .hero-floating-card { bottom: 20px; left: 20px; right: 20px; }
            footer .col-2 { display: none; } /* 移动端简化页脚 */
        }

@media (max-width: 768px) {
    .container { padding: 0 20px; }
    section { padding: 60px 0; }
    .hero { padding: 40px 0 60px; }
    .hero h1 { font-size: 2.8rem; }
    .hero p.lead { padding: 0; font-size: 1.1rem; }

    /* --- 彻底修复表单布局（宽度撑满 + 内部空间释放） --- */
    
    /* 1. 强制外层卡片撑满屏幕，解决大板块两边留白太多的问题 */
    #contact-expert .glass-card {
        display: block !important; 
        width: 100% !important;
        max-width: 100% !important;
        box-sizing: border-box !important;
        border-radius: 16px !important;
    }
    
    /* 2. 强制内部网格转为上下堆叠 */
    #contact-expert .grid-12 {
        display: flex !important;
        flex-direction: column !important;
        gap: 0 !important;
        width: 100% !important;
    }
    
    /* 3. 覆盖 HTML 内联 padding，释放内部横向空间 */
    #contact-expert .col-5 {
        padding: 40px 20px !important;
        width: 100% !important;
        box-sizing: border-box !important;
    }
    #contact-expert .col-7 {
        padding: 30px 20px !important;
        width: 100% !important;
        box-sizing: border-box !important;
    }
    
    /* 4. 强制双列输入框变单列，防止手机上姓名输入框太挤 */
    #contact-expert form > div[style*="grid-template-columns"] {
        display: flex !important;
        flex-direction: column !important;
        gap: 24px !important;
    }

    /* 5. 保护电话号码下拉框与输入框的比例 */
    #contact-expert form select[style*="width: 35%"] {
        width: 35% !important;
        min-width: 35% !important;
        padding: 14px 6px !important;
    }
    #contact-expert form input[type="tel"] {
        width: 65% !important;
        min-width: 65% !important;
    }
}
/* --- 终极修复：消除 HTML 结构嵌套导致的表单双重缩水问题 --- */
#contact-expert .container {
    padding: 0 !important;
    width: 100% !important;
    max-width: 100% !important;
}           
/* --- 移动端表单交互体验与 iOS 兼容性深度优化 --- */
@media (max-width: 768px) {
    /* 1. 强制 16px 字体，彻底终结 iPhone 点击输入框自动放大页面的反人类 Bug */
    #contact-expert form input,
    #contact-expert form select {
        font-size: 16px !important; 
        /* 2. 抹除 iOS 默认的丑陋内部阴影和立体感，还原干净的 UI */
        -webkit-appearance: none !important; 
        appearance: none !important;
        border-radius: 8px !important; /* 统一圆角 */
    }

    /* 单独把下拉菜单右边的圆角去掉，好跟电话输入框拼接 */
    #contact-expert form select[style*="width: 35%"] {
        border-radius: 8px 0 0 8px !important;
        /* 3. 稍微向右借 3% 的空间，防止国家名字太长 */
        width: 38% !important;
        min-width: 38% !important;
        /* 4. 如果字还是太长，优雅地显示为省略号，绝不把输入框挤破 */
        text-overflow: ellipsis !important;
        white-space: nowrap !important;
        overflow: hidden !important;
        /* 补偿去掉默认小箭头后的右侧间距 */
        background-image: url("data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%23475569%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-5%200-9.3%201.8-12.9%205.4A17.6%2017.6%200%200%200%200%2082.2c0%205%201.8%209.3%205.4%2012.9l128%20127.9c3.6%203.6%207.8%205.4%2012.8%205.4s9.2-1.8%2012.8-5.4L287%2095c3.5-3.5%205.4-7.8%205.4-12.8%200-5-1.9-9.2-5.5-12.8z%22%2F%3E%3C%2Fsvg%3E") !important;
        background-repeat: no-repeat !important;
        background-position: right 8px top 50% !important;
        background-size: 10px auto !important;
        padding-right: 22px !important;
    }
    
    #contact-expert form input[type="tel"] {
        border-radius: 0 8px 8px 0 !important;
        width: 62% !important;
        min-width: 62% !important;
    }
}