/* roulang page: index */
:root {
      --primary: #0A1F2E;
      --secondary: #00C49A;
      --accent: #FF6B3D;
      --bg-light: #F8FAFB;
      --white: #FFFFFF;
      --text-dark: #3A4454;
      --text-muted: #7B8794;
      --border-light: #E5E9F0;
      --deep-bg: #0A1F2E;
      --footer-dark: #061520;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-sm: 0 2px 8px rgba(10,31,46,0.06);
      --shadow-hover: 0 8px 24px rgba(10,31,46,0.12);
      --transition-smooth: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --font-mono: "SF Mono", "Menlo", "Consolas", monospace;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.6;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 640px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 导航透明玻璃沉浸 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(255,255,255,0.15);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.2);
      box-shadow: 0 4px 20px rgba(0,0,0,0.08);
      transition: background 0.3s, box-shadow 0.3s, border-color 0.3s;
      padding: 12px 0;
    }
    #nav.scrolled {
      background: #FFFFFF;
      backdrop-filter: none;
      -webkit-backdrop-filter: none;
      border-bottom: 1px solid var(--border-light);
      box-shadow: 0 2px 12px rgba(0,0,0,0.06);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      text-decoration: none;
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      font-size: 22px;
      color: var(--secondary);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--primary);
      text-decoration: none;
      position: relative;
      transition: color 0.2s;
    }
    .nav-links a:after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -4px;
      width: 0;
      height: 2px;
      background: var(--secondary);
      transition: width 0.25s;
    }
    .nav-links a:hover {
      color: var(--secondary);
    }
    .nav-links a:hover:after {
      width: 100%;
    }
    .cta-btn {
      background: var(--accent);
      color: white;
      padding: 12px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: var(--transition-smooth);
      display: inline-block;
      font-size: 16px;
      border: none;
      cursor: pointer;
    }
    .cta-btn:hover {
      background: #E55A2F;
      transform: scale(1.03);
      color: white;
      text-decoration: none;
    }
    .secondary-btn {
      background: transparent;
      border: 2px solid var(--secondary);
      color: var(--secondary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: var(--transition-smooth);
      display: inline-block;
    }
    .secondary-btn:hover {
      background: var(--secondary);
      color: white;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 4px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: 0.2s;
    }
    @media (max-width: 1024px) {
      .nav-links {
        gap: 20px;
      }
    }
    @media (max-width: 640px) {
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: white;
        padding: 24px;
        box-shadow: var(--shadow-hover);
        border-bottom: 1px solid var(--border-light);
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .nav-inner {
        flex-wrap: wrap;
      }
    }
    /* Hero */
    #hero {
      height: 100vh;
      min-height: 700px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
    }
    #hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(10,31,46,0.85) 0%, rgba(10,31,46,0.4) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      width: 100%;
      padding: 0 24px;
    }
    .hero-title {
      font-size: 48px;
      font-weight: 700;
      color: white;
      letter-spacing: -0.02em;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      max-width: 600px;
      margin: 0 auto 40px;
    }
    .metric-cards {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 24px;
      margin-bottom: 40px;
    }
    .metric-card {
      background: rgba(255,255,255,0.1);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      border: 1px solid rgba(255,255,255,0.2);
      border-radius: 16px;
      padding: 24px 28px;
      min-width: 150px;
      color: white;
    }
    .metric-number {
      font-family: var(--font-mono);
      font-size: 32px;
      font-weight: 600;
      color: var(--secondary);
    }
    .metric-label {
      font-size: 14px;
      color: rgba(255,255,255,0.75);
      margin-top: 8px;
    }
    @media (max-width: 640px) {
      #hero {
        height: auto;
        min-height: 80vh;
        padding: 100px 0 60px;
      }
      .hero-title {
        font-size: 32px;
        line-height: 1.3;
      }
      .metric-cards {
        gap: 16px;
      }
      .metric-card {
        padding: 16px;
        min-width: 130px;
      }
    }
    /* 区块通用 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 640px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 16px;
      letter-spacing: -0.02em;
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-muted);
      margin-bottom: 48px;
    }
    /* 服务矩阵4列 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition-smooth);
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .service-icon {
      width: 64px;
      height: 64px;
      margin-bottom: 20px;
      color: var(--secondary);
      font-size: 40px;
    }
    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .service-card p {
      color: var(--text-muted);
      margin-bottom: 20px;
      flex: 1;
    }
    .arrow-link {
      align-self: flex-start;
      color: var(--secondary);
      font-weight: 600;
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: gap 0.2s;
    }
    .arrow-link:hover {
      gap: 10px;
      color: #00a383;
    }
    @media (max-width: 1024px) and (min-width: 641px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 结果对比 */
    .compare-row {
      display: flex;
      gap: 40px;
      align-items: center;
      flex-wrap: wrap;
    }
    .compare-card {
      flex: 1;
      background: white;
      border-radius: var(--radius-card);
      padding: 40px;
      box-shadow: var(--shadow-sm);
    }
    .compare-card.old {
      background: #f4f6f9;
    }
    .compare-card.new {
      background: var(--white);
      border: 2px solid var(--secondary);
    }
    .vs-badge {
      font-weight: 700;
      font-size: 24px;
      color: var(--accent);
      margin: 0 16px;
    }
    .compare-list {
      list-style: none;
      padding: 0;
    }
    .compare-list li {
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    @media (max-width: 640px) {
      .compare-row {
        flex-direction: column;
      }
    }
    /* 优势3列 */
    .adv-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .adv-item {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-card);
    }
    @media (max-width: 640px) {
      .adv-grid {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .accordion-item {
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
    }
    .accordion-question {
      padding: 20px 24px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .accordion-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: #F8FAFB;
      padding: 0 24px;
    }
    .accordion-answer.open {
      max-height: 300px;
      padding: 24px;
    }
    /* 表单区域 */
    #contact {
      background: var(--deep-bg);
      color: white;
      padding: 80px 0;
    }
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 14px 16px;
      border-radius: var(--radius-btn);
      border: 1px solid #D1D9E0;
      margin-bottom: 16px;
      background: white;
    }
    @media (max-width: 640px) {
      .contact-grid {
        grid-template-columns: 1fr;
      }
    }
    footer {
      background: var(--footer-dark);
      color: #B0C4D8;
      padding: 40px 0 20px;
      font-size: 14px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 30px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }