/* ===== 全局重置与基础 ===== */
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    :root {
      --primary: #0b5cff;
      --primary-light: #4a8cff;
      --primary-dark: #003bb3;
      --accent: #ff6a3d;
      --accent-soft: #fff0ea;
      --neutral-50: #f8faff;
      --neutral-100: #f1f5fe;
      --neutral-200: #e3eaf8;
      --neutral-700: #1e2b4a;
      --neutral-800: #0b1a3a;
      --neutral-900: #030f2b;
      --gray-600: #4a5a7a;
      --gray-500: #6b7b9b;
      --white: #ffffff;
      --shadow-sm: 0 4px 12px rgba(11, 92, 255, 0.06);
      --shadow-md: 0 12px 32px rgba(11, 92, 255, 0.10);
      --shadow-lg: 0 24px 48px rgba(11, 92, 255, 0.12);
      --radius-card: 20px;
      --radius-btn: 48px;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background: var(--neutral-50);
      color: var(--neutral-700);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    ul, ol {
      list-style: none;
    }
    button, input, select, textarea {
      font-family: inherit;
      font-size: inherit;
      outline: none;
    }
    .container {
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 通用动画 */
    @keyframes fadeUp {
      from { opacity: 0; transform: translateY(24px); }
      to { opacity: 1; transform: translateY(0); }
    }
    @keyframes floatSoft {
      0%, 100% { transform: translateY(0); }
      50% { transform: translateY(-8px); }
    }
    @keyframes pulseGlow {
      0%, 100% { box-shadow: 0 0 0 0 rgba(11, 92, 255, 0.3); }
      50% { box-shadow: 0 0 0 12px rgba(11, 92, 255, 0); }
    }
    .reveal {
      opacity: 0;
      transform: translateY(28px);
      transition: opacity 0.7s ease, transform 0.7s ease;
    }
    .reveal.visible {
      opacity: 1;
      transform: translateY(0);
    }
    /* ===== 导航 ===== */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.88);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid var(--neutral-200);
      box-shadow: 0 2px 20px rgba(0,0,0,0.02);
    }
    .nav-wrap {
      display: flex;
      align-items: center;
      justify-content: space-between;
      min-height: 72px;
      gap: 16px;
    }
    .brand {
      display: flex;
      align-items: center;
      gap: 10px;
      flex-shrink: 0;
    }
    .brand img {
      width: 120px;
      height: auto;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0; /* 按需求设置 */
      flex-wrap: wrap;
    }
    .nav-links a {
      font-size: 0.9rem;
      font-weight: 500;
      padding: 8px 12px;
      color: var(--neutral-700);
      border-radius: 20px;
      transition: color var(--transition), background var(--transition);
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--primary);
      background: var(--neutral-100);
    }
    .nav-cta {
      display: flex;
      align-items: center;
      gap: 12px;
      flex-shrink: 0;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      border: none;
      cursor: pointer;
      transition: all var(--transition);
      text-align: center;
      line-height: 1.3;
    }
    .btn-primary {
      background: var(--primary);
      color: #fff;
      box-shadow: 0 6px 18px rgba(11, 92, 255, 0.3);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 10px 26px rgba(11, 92, 255, 0.4);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 1.5px solid var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: #fff;
      transform: translateY(-2px);
    }
    .btn-lg {
      padding: 14px 36px;
      font-size: 1rem;
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      width: 40px;
      height: 40px;
      cursor: pointer;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 5px;
      border-radius: 8px;
    }
    .menu-toggle span {
      display: block;
      width: 22px;
      height: 2.5px;
      background: var(--neutral-800);
      border-radius: 4px;
      transition: var(--transition);
    }
    /* ===== 首屏 Hero (无图片) ===== */
    .hero {
      position: relative;
      padding: 80px 0 80px;
      background: linear-gradient(145deg, #f0f5ff 0%, #ffffff 45%, #eaf1ff 100%);
      overflow: hidden;
    }
    .hero::before {
      content: "";
      position: absolute;
      width: 600px;
      height: 600px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(11, 92, 255, 0.07) 0%, transparent 70%);
      top: -200px;
      right: -100px;
      z-index: 0;
      animation: floatSoft 8s ease-in-out infinite;
    }
    .hero::after {
      content: "";
      position: absolute;
      width: 400px;
      height: 400px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(255, 106, 61, 0.06) 0%, transparent 70%);
      bottom: -150px;
      left: -100px;
      z-index: 0;
      animation: floatSoft 10s ease-in-out infinite reverse;
    }
    .hero .container {
      position: relative;
      z-index: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
    }
    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(11, 92, 255, 0.08);
      border: 1px solid rgba(11, 92, 255, 0.15);
      padding: 6px 18px;
      border-radius: 40px;
      font-size: 0.85rem;
      font-weight: 500;
      color: var(--primary);
      margin-bottom: 24px;
      animation: fadeUp 0.8s ease;
    }
    .hero h1 {
      font-size: clamp(2rem, 5vw, 3.6rem);
      font-weight: 800;
      color: var(--neutral-900);
      line-height: 1.25;
      max-width: 1000px;
      margin-bottom: 20px;
      letter-spacing: -0.02em;
      animation: fadeUp 0.9s ease 0.1s both;
    }
    .hero h1 .highlight {
      color: var(--primary);
      position: relative;
      display: inline-block;
    }
    .hero-sub {
      font-size: clamp(1rem, 1.5vw, 1.2rem);
      color: var(--gray-600);
      max-width: 780px;
      margin-bottom: 32px;
      line-height: 1.7;
      animation: fadeUp 0.9s ease 0.2s both;
    }
    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      justify-content: center;
      margin-bottom: 48px;
      animation: fadeUp 0.9s ease 0.3s both;
    }
    /* 数据指标卡片 (首屏底部) */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      width: 100%;
      max-width: 900px;
      margin-top: 8px;
      animation: fadeUp 0.9s ease 0.4s both;
    }
    .metric-item {
      background: rgba(255, 255, 255, 0.75);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255, 255, 255, 0.9);
      box-shadow: var(--shadow-sm);
      border-radius: 20px;
      padding: 18px 12px;
      transition: transform var(--transition), box-shadow var(--transition);
    }
    .metric-item:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .metric-value {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
    }
    .metric-label {
      font-size: 0.8rem;
      color: var(--gray-600);
      margin-top: 4px;
      font-weight: 500;
    }
    /* ===== 通用区块 ===== */
    .section {
      padding: 80px 0;
    }
    .section-header {
      text-align: center;
      max-width: 720px;
      margin: 0 auto 48px;
    }
    .section-subtitle {
      display: inline-block;
      font-size: 0.8rem;
      font-weight: 700;
      letter-spacing: 0.08em;
      text-transform: uppercase;
      color: var(--primary);
      background: rgba(11, 92, 255, 0.08);
      padding: 4px 16px;
      border-radius: 40px;
      margin-bottom: 12px;
    }
    .section-header h2 {
      font-size: clamp(1.7rem, 3.2vw, 2.4rem);
      font-weight: 800;
      color: var(--neutral-900);
      line-height: 1.3;
      margin-bottom: 12px;
    }
    .section-header p {
      font-size: 1rem;
      color: var(--gray-600);
      line-height: 1.7;
    }
    /* ===== 平台介绍 ===== */
    .about-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .about-text h2 {
      font-size: 2rem;
      font-weight: 800;
      color: var(--neutral-900);
      margin-bottom: 20px;
      line-height: 1.3;
    }
    .about-text p {
      color: var(--gray-600);
      margin-bottom: 16px;
      font-size: 1rem;
    }
    .about-features {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
      margin-top: 24px;
    }
    .about-feature {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 500;
      font-size: 0.95rem;
    }
    .about-feature .dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: var(--primary);
      flex-shrink: 0;
    }
    .about-visual {
      background: linear-gradient(150deg, var(--neutral-100), #ffffff);
      border-radius: 32px;
      padding: 40px;
      box-shadow: var(--shadow-md);
      border: 1px solid var(--neutral-200);
    }
    .about-tag-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
    }
    .tag {
      background: #fff;
      border: 1px solid var(--neutral-200);
      padding: 6px 18px;
      border-radius: 40px;
      font-size: 0.85rem;
      font-weight: 500;
      color: var(--neutral-700);
      transition: all var(--transition);
    }
    .tag:hover {
      border-color: var(--primary);
      color: var(--primary);
      box-shadow: var(--shadow-sm);
      transform: translateY(-2px);
    }
    /* ===== 服务能力卡片 ===== */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
      gap: 24px;
    }
    .service-card {
      background: #fff;
      border-radius: var(--radius-card);
      padding: 28px 22px;
      border: 1px solid var(--neutral-200);
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
      border-color: rgba(11, 92, 255, 0.3);
    }
    .service-icon {
      width: 48px;
      height: 48px;
      border-radius: 14px;
      background: var(--neutral-100);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.6rem;
      color: var(--primary);
      margin-bottom: 4px;
    }
    .service-card h3 {
      font-size: 1.1rem;
      font-weight: 700;
      color: var(--neutral-900);
    }
    .service-card p {
      font-size: 0.9rem;
      color: var(--gray-600);
      line-height: 1.6;
    }
    /* ===== 流程步骤 ===== */
    .process-steps {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      counter-reset: step;
    }
    .step-item {
      text-align: center;
      position: relative;
      padding: 24px 16px;
      background: #fff;
      border-radius: 20px;
      border: 1px solid var(--neutral-200);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .step-item:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .step-num {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: var(--primary);
      color: #fff;
      font-weight: 800;
      font-size: 1.2rem;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      box-shadow: 0 6px 14px rgba(11, 92, 255, 0.25);
    }
    .step-item h3 {
      font-size: 1rem;
      font-weight: 700;
      margin-bottom: 6px;
      color: var(--neutral-800);
    }
    .step-item p {
      font-size: 0.85rem;
      color: var(--gray-600);
    }
    /* ===== 对比评测 ===== */
    .compare-wrap {
      background: linear-gradient(135deg, #ffffff, #f5f9ff);
      border-radius: 32px;
      padding: 40px 32px;
      border: 1px solid var(--neutral-200);
      box-shadow: var(--shadow-md);
    }
    .compare-header {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
      margin-bottom: 32px;
    }
    .compare-score {
      display: flex;
      align-items: center;
      gap: 20px;
    }
    .score-big {
      font-size: 3.6rem;
      font-weight: 900;
      color: var(--primary);
      line-height: 1;
    }
    .score-meta {
      display: flex;
      flex-direction: column;
      gap: 4px;
    }
    .stars {
      color: #ffb800;
      font-size: 1.2rem;
      letter-spacing: 2px;
    }
    .score-meta span {
      font-size: 0.85rem;
      color: var(--gray-600);
    }
    .compare-table-wrap {
      overflow-x: auto;
      border-radius: 16px;
      border: 1px solid var(--neutral-200);
      background: #fff;
    }
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      min-width: 620px;
      font-size: 0.9rem;
    }
    .compare-table th {
      background: var(--neutral-100);
      text-align: left;
      padding: 14px 18px;
      font-weight: 700;
      color: var(--neutral-800);
      border-bottom: 1px solid var(--neutral-200);
    }
    .compare-table td {
      padding: 13px 18px;
      border-bottom: 1px solid var(--neutral-100);
      color: var(--neutral-700);
    }
    .compare-table tr:last-child td {
      border-bottom: none;
    }
    .compare-table .check {
      color: var(--primary);
      font-weight: 700;
    }
    /* ===== 案例与用户评论 ===== */
    .case-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .case-card {
      background: #fff;
      border-radius: 20px;
      overflow: hidden;
      border: 1px solid var(--neutral-200);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .case-img {
      width: 100%;
      aspect-ratio: 16/9;
      overflow: hidden;
      background: var(--neutral-100);
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.5s ease;
    }
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    .case-body {
      padding: 18px 20px;
    }
    .case-body h3 {
      font-size: 1.05rem;
      font-weight: 700;
      margin-bottom: 6px;
    }
    .case-body p {
      font-size: 0.85rem;
      color: var(--gray-600);
    }
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
      gap: 20px;
      margin-top: 32px;
    }
    .review-card {
      background: #fff;
      border-radius: 18px;
      padding: 22px 20px;
      border: 1px solid var(--neutral-200);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .review-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .review-text {
      font-size: 0.9rem;
      color: var(--neutral-700);
      line-height: 1.6;
    }
    .review-author {
      display: flex;
      align-items: center;
      gap: 10px;
      border-top: 1px solid var(--neutral-100);
      padding-top: 12px;
    }
    .avatar {
      width: 38px;
      height: 38px;
      border-radius: 50%;
      background: var(--neutral-100);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 0.85rem;
      color: var(--primary);
    }
    .author-info {
      display: flex;
      flex-direction: column;
    }
    .author-name {
      font-weight: 600;
      font-size: 0.85rem;
      color: var(--neutral-800);
    }
    .author-title {
      font-size: 0.75rem;
      color: var(--gray-500);
    }
    /* ===== FAQ ===== */
    .faq-list {
      max-width: 860px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      background: #fff;
      border-radius: 16px;
      border: 1px solid var(--neutral-200);
      overflow: hidden;
      transition: var(--transition);
    }
    .faq-item:hover {
      border-color: rgba(11, 92, 255, 0.3);
    }
    .faq-question {
      width: 100%;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 18px 22px;
      background: none;
      border: none;
      font-weight: 600;
      font-size: 0.98rem;
      color: var(--neutral-800);
      text-align: left;
      cursor: pointer;
      gap: 16px;
      transition: background var(--transition);
    }
    .faq-question:hover {
      background: var(--neutral-50);
    }
    .faq-icon {
      font-size: 1.2rem;
      font-weight: 300;
      transition: transform var(--transition);
      flex-shrink: 0;
      color: var(--primary);
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s ease;
      padding: 0 22px;
      color: var(--gray-600);
      font-size: 0.9rem;
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 0 22px 20px;
    }
    /* ===== 表单 ===== */
    .form-wrap {
      display: grid;
      grid-template-columns: 1fr 1.4fr;
      gap: 48px;
      align-items: start;
      background: #fff;
      border-radius: 32px;
      padding: 48px;
      border: 1px solid var(--neutral-200);
      box-shadow: var(--shadow-md);
    }
    .form-info h2 {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--neutral-900);
      margin-bottom: 16px;
    }
    .form-info p {
      color: var(--gray-600);
      margin-bottom: 24px;
      font-size: 0.95rem;
    }
    .contact-list {
      display: flex;
      flex-direction: column;
      gap: 14px;
      font-size: 0.9rem;
      color: var(--neutral-700);
    }
    .contact-list li {
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .contact-list .icon {
      width: 32px;
      height: 32px;
      background: var(--neutral-100);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      flex-shrink: 0;
    }
    .demand-form {
      display: grid;
      gap: 16px;
    }
    .form-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }
    .form-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }
    .form-group label {
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--neutral-800);
    }
    .form-group input,
    .form-group select,
    .form-group textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1.5px solid var(--neutral-200);
      border-radius: 12px;
      font-size: 0.9rem;
      background: var(--neutral-50);
      transition: border var(--transition), box-shadow var(--transition);
    }
    .form-group input:focus,
    .form-group select:focus,
    .form-group textarea:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(11, 92, 255, 0.08);
    }
    .form-group textarea {
      resize: vertical;
      min-height: 110px;
    }
    .form-submit {
      margin-top: 4px;
    }
    .form-submit .btn {
      width: 100%;
      padding: 14px;
      font-size: 1rem;
    }
    /* ===== 文章列表与友情链接 ===== */
    .article-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
      gap: 16px;
    }
    .article-item {
      background: #fff;
      border: 1px solid var(--neutral-200);
      border-radius: 16px;
      padding: 18px 18px;
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .article-item:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
      border-color: rgba(11, 92, 255, 0.3);
    }
    .article-item h3 {
      font-size: 0.95rem;
      font-weight: 600;
      color: var(--neutral-800);
    }
    .article-item span {
      font-size: 0.8rem;
      color: var(--gray-500);
    }
    .friend-links {
      display: flex;
      flex-wrap: wrap;
      gap: 12px 20px;
      justify-content: center;
      margin-top: 24px;
    }
    .friend-links a {
      font-size: 0.85rem;
      color: var(--gray-600);
      transition: color var(--transition);
      padding: 4px 0;
    }
    .friend-links a:hover {
      color: var(--primary);
    }
    /* ===== 页脚 ===== */
    .site-footer {
      background: var(--neutral-900);
      color: #b0c4de;
      padding: 48px 0 28px;
      margin-top: 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.4fr 1fr 1fr 1fr;
      gap: 32px;
      padding-bottom: 28px;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .footer-brand img {
      width: 120px;
      margin-bottom: 12px;
      
    }
    .footer-brand p {
      font-size: 0.85rem;
      color: #9ab0d0;
      line-height: 1.7;
      margin-bottom: 12px;
    }
    .footer-col h4 {
      color: #fff;
      font-size: 0.9rem;
      margin-bottom: 14px;
      font-weight: 600;
    }
    .footer-col ul {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .footer-col a {
      font-size: 0.85rem;
      color: #9ab0d0;
      transition: color var(--transition);
    }
    .footer-col a:hover {
      color: #fff;
    }
    .footer-bottom {
      padding-top: 24px;
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      align-items: center;
      gap: 12px;
      font-size: 0.8rem;
      color: #7a94b8;
    }
    /* ===== 浮动客服 ===== */
    .float-service {
      position: fixed;
      right: 24px;
      bottom: 88px;
      z-index: 99;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .float-btn {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      background: #fff;
      border: 1px solid var(--neutral-200);
      box-shadow: var(--shadow-md);
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: var(--transition);
      font-size: 1.2rem;
      color: var(--primary);
    }
    .float-btn:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-lg);
    }
    .back-top {
      position: fixed;
      right: 24px;
      bottom: 24px;
      width: 46px;
      height: 46px;
      border-radius: 50%;
      background: var(--primary);
      color: #fff;
      border: none;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.2rem;
      box-shadow: 0 8px 24px rgba(11, 92, 255, 0.35);
      opacity: 0;
      visibility: hidden;
      transition: var(--transition);
      z-index: 99;
    }
    .back-top.visible {
      opacity: 1;
      visibility: visible;
    }
    .back-top:hover {
      background: var(--primary-dark);
      transform: translateY(-3px);
    }
    /* ===== 响应式 ===== */
    @media (max-width: 1024px) {
      .about-grid { grid-template-columns: 1fr; }
      .process-steps { grid-template-columns: repeat(2, 1fr); }
      .form-wrap { grid-template-columns: 1fr; padding: 32px; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 860px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        align-items: stretch;
        padding: 16px 24px;
        border-bottom: 1px solid var(--neutral-200);
        box-shadow: var(--shadow-md);
        gap: 4px;
      }
      .nav-links.open { display: flex; }
      .nav-links a { padding: 10px 12px; border-radius: 10px; }
      .menu-toggle { display: flex; }
      .nav-cta .btn-outline { display: none; }
      .hero { padding: 56px 0 56px; }
      .metrics-grid { grid-template-columns: repeat(2, 1fr); }
      .case-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 640px) {
      .container { padding: 0 16px; }
      .hero h1 { font-size: 1.9rem; }
      .hero-actions { flex-direction: column; width: 100%; }
      .hero-actions .btn { width: 100%; }
      .metrics-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
      .metric-value { font-size: 1.4rem; }
      .process-steps { grid-template-columns: 1fr; }
      .form-row { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .compare-header { flex-direction: column; align-items: flex-start; }
      .form-wrap { padding: 24px; }
      .section { padding: 56px 0; }
      .about-features { grid-template-columns: 1fr; }
    }
    @media (prefers-reduced-motion: reduce) {
      .reveal { opacity: 1; transform: none; transition: none; }
      .hero::before, .hero::after { animation: none; }
      * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
    }