/* roulang page: index */
:root {
      --primary-black: #1A1A1A;
      --accent-orange: #E94E1F;
      --accent-orange-hover: #C43D14;
      --bg-warm: #FAF9F7;
      --bg-light-gray: #F5F3F0;
      --card-white: #FFFFFF;
      --border-light: #E8E4DF;
      --text-main: #1A1A1A;
      --text-secondary: #5A5A5A;
      --text-muted: #8A8A8A;
      --text-footer: #B3B3B3;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
      --shadow-sm: 0 4px 12px rgba(26, 26, 26, 0.06);
      --shadow-md: 0 8px 24px rgba(26, 26, 26, 0.08);
      --radius-card: 8px;
      --radius-btn: 6px;
      --radius-input: 6px;
      --transition: all 0.2s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

    button, input, textarea {
      font-family: inherit;
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--card-white);
      border-bottom: 1px solid var(--border-light);
      height: 64px;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 20px;
      color: var(--primary-black);
      letter-spacing: -0.3px;
    }

    .logo-icon {
      width: 12px;
      height: 12px;
      background: var(--accent-orange);
      display: inline-block;
      border-radius: 2px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 4px 0;
      white-space: nowrap;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-orange);
      transition: width 0.2s ease;
    }

    .nav-links a:hover {
      color: var(--accent-orange);
    }

    .nav-links a:hover::after {
      width: 100%;
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      cursor: pointer;
      color: var(--primary-black);
    }

    /* Hero */
    .hero {
      padding: 60px 0 70px;
      background: var(--bg-warm);
      position: relative;
      overflow: hidden;
    }

    .hero::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.08;
      pointer-events: none;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 40px;
      position: relative;
      z-index: 2;
    }

    .hero-left {
      flex: 1;
    }

    .hero-left h1 {
      font-size: 52px;
      font-weight: 700;
      line-height: 1.25;
      letter-spacing: -0.5px;
      color: var(--primary-black);
      margin-bottom: 20px;
    }

    .hero-left .subtitle {
      font-size: 17px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }

    .btn-primary {
      background: var(--accent-orange);
      color: white;
      border: none;
      padding: 14px 32px;
      font-size: 16px;
      font-weight: 600;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 6px;
      box-shadow: 0 4px 10px rgba(233, 78, 31, 0.2);
    }

    .btn-primary:hover {
      background: var(--accent-orange-hover);
      transform: translateY(-2px);
      box-shadow: 0 6px 16px rgba(233, 78, 31, 0.3);
    }

    .hero-right {
      flex: 0.9;
      display: flex;
      flex-direction: column;
      gap: 16px;
      position: relative;
    }

    .data-card-stack {
      background: var(--card-white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 18px 22px;
      display: flex;
      align-items: center;
      gap: 16px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      position: relative;
    }

    .data-card-stack:nth-child(1) {
      align-self: flex-end;
      margin-right: 20px;
    }

    .data-card-stack:nth-child(2) {
      align-self: flex-start;
      margin-left: 20px;
    }

    .data-card-stack:nth-child(3) {
      align-self: flex-end;
      margin-right: 0;
    }

    .data-icon {
      font-size: 28px;
      color: var(--accent-orange);
      width: 40px;
      text-align: center;
    }

    .data-text strong {
      display: block;
      font-size: 22px;
      font-weight: 700;
      color: var(--primary-black);
    }

    .data-text span {
      font-size: 13px;
      color: var(--text-muted);
    }

    /* 板块通用 */
    section {
      padding: 70px 0;
    }

    .section-title {
      font-size: 34px;
      font-weight: 600;
      letter-spacing: -0.3px;
      margin-bottom: 16px;
      color: var(--primary-black);
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .section-title .num {
      font-size: 20px;
      color: var(--accent-orange);
      font-weight: 700;
      border: 1px solid var(--accent-orange);
      border-radius: 4px;
      padding: 0 8px;
      line-height: 1.4;
    }

    .section-desc {
      color: var(--text-secondary);
      margin-bottom: 40px;
      max-width: 700px;
      font-size: 16px;
    }

    .bg-gray {
      background: var(--bg-light-gray);
    }

    /* 数据看板 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
      text-align: center;
    }

    .metric-item .metric-number {
      font-size: 42px;
      font-weight: 700;
      color: var(--accent-orange);
      line-height: 1.2;
    }

    .metric-item .metric-label {
      font-size: 15px;
      color: var(--text-secondary);
      margin-top: 6px;
    }

    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .service-card {
      background: var(--card-white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      transition: var(--transition);
    }

    .service-card:hover {
      border-color: var(--accent-orange);
      box-shadow: var(--shadow-sm);
    }

    .service-icon {
      font-size: 36px;
      color: var(--accent-orange);
      margin-bottom: 20px;
    }

    .service-card h3 {
      font-weight: 600;
      font-size: 20px;
      margin-bottom: 12px;
    }

    .service-card p {
      color: var(--text-secondary);
      font-size: 14px;
      margin-bottom: 18px;
      line-height: 1.65;
    }

    .text-link {
      color: var(--accent-orange);
      font-weight: 600;
      font-size: 14px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      border-bottom: 1px solid transparent;
    }

    .text-link:hover {
      border-bottom: 1px solid var(--accent-orange);
    }

    /* 对比 */
    .compare-wrapper {
      display: flex;
      align-items: center;
      gap: 30px;
      justify-content: center;
      flex-wrap: wrap;
    }

    .compare-card {
      background: var(--card-white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px;
      flex: 1 1 280px;
      max-width: 380px;
      transition: var(--transition);
    }

    .compare-card.negative {
      opacity: 0.8;
    }

    .compare-card.positive {
      border-color: var(--accent-orange);
      background: #FFF9F7;
    }

    .compare-card h4 {
      font-size: 18px;
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .vs-badge {
      background: var(--primary-black);
      color: white;
      width: 48px;
      height: 48px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 18px;
    }

    .footnote {
      text-align: center;
      font-size: 13px;
      color: var(--text-muted);
      margin-top: 28px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }

    .faq-question {
      display: flex;
      align-items: center;
      justify-content: space-between;
      cursor: pointer;
      font-weight: 600;
      font-size: 17px;
      gap: 12px;
    }

    .faq-question .q-num {
      color: var(--accent-orange);
      font-weight: 700;
      margin-right: 8px;
    }

    .faq-toggle {
      font-size: 22px;
      color: var(--accent-orange);
      transition: transform 0.2s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 14px;
      padding-left: 32px;
      margin-top: 0;
    }

    .faq-item.open .faq-answer {
      max-height: 150px;
      margin-top: 12px;
    }

    /* 表单 */
    .contact-form {
      max-width: 560px;
      margin: 0 auto;
      background: var(--card-white);
      padding: 40px;
      border-radius: var(--radius-card);
      border: 1px solid var(--border-light);
    }

    .form-group {
      margin-bottom: 20px;
    }

    .form-group input {
      width: 100%;
      padding: 14px 16px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-input);
      font-size: 15px;
      background: #FAFAFA;
      transition: var(--transition);
    }

    .form-group input:focus {
      outline: none;
      border-color: var(--accent-orange);
      box-shadow: 0 0 0 3px rgba(233,78,31,0.1);
    }

    .btn-full {
      width: 100%;
    }

    .form-guide {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 24px;
      text-align: center;
    }

    /* Footer */
    .footer {
      background: var(--primary-black);
      color: var(--text-footer);
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      color: white;
      font-weight: 600;
      margin-bottom: 16px;
      font-size: 16px;
    }

    .footer-col ul {
      list-style: none;
    }

    .footer-col li {
      margin-bottom: 10px;
      font-size: 14px;
    }

    .footer-col a:hover {
      color: var(--accent-orange);
    }

    .copyright {
      border-top: 1px solid #2A2A2A;
      padding-top: 24px;
      font-size: 13px;
      text-align: center;
      color: #7A7A7A;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-left h1 { font-size: 40px; }
      .metrics-grid { grid-template-columns: repeat(2,1fr); }
      .services-grid { grid-template-columns: repeat(2,1fr); }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .hero-grid { flex-direction: column; text-align: center; }
      .hero-left h1 { font-size: 34px; }
      .hero-right { width: 100%; margin-top: 24px; }
      .services-grid { grid-template-columns: 1fr; }
      .metrics-grid { grid-template-columns: 1fr 1fr; }
      .compare-wrapper { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
      .section-title { font-size: 28px; }
    }

    @media (max-width: 520px) {
      .metrics-grid { grid-template-columns: 1fr; }
      .contact-form { padding: 24px; }
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      background: white;
      border-bottom: 1px solid var(--border-light);
      flex-direction: column;
      padding: 24px;
      gap: 20px;
      z-index: 40;
    }

    .mobile-menu.active { display: flex; }