/* roulang page: index */
:root {
      --primary: #FF4D00;
      --primary-hover: #D43F00;
      --accent: #00E5FF;
      --dark: #1A1A1A;
      --bg: #F5F3F0;
      --text: #1E1E1E;
      --muted: #6B6B6B;
      --border-light: #E5E2DF;
      --card-shadow: 0 4px 20px rgba(0,0,0,0.06);
      --card-shadow-hover: 0 12px 32px rgba(0,0,0,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-title: "Noto Sans SC", "PingFang SC Heavy", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      --font-body: "Noto Sans SC", "PingFang SC Regular", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      --font-number: "Oswald", "DIN Alternate Bold", "Inter", sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-body);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input, textarea {
      font-family: inherit;
      outline: none;
    }
    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      box-shadow: 0 1px 0 rgba(0,0,0,0.05);
      z-index: 1000;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .brand {
      font-family: var(--font-title);
      font-weight: 900;
      font-size: 1.8rem;
      color: var(--dark);
      letter-spacing: -0.5px;
      display: flex;
      align-items: baseline;
      gap: 2px;
    }
    .brand span {
      color: var(--primary);
      font-size: 1.1rem;
      font-weight: 700;
      margin-left: 4px;
      letter-spacing: 0;
    }
    .nav-menu {
      display: flex;
      gap: 2rem;
      align-items: center;
      font-weight: 500;
    }
    .nav-menu a {
      color: var(--text);
      transition: color 0.2s;
      font-size: 1rem;
      padding: 0.25rem 0;
      border-bottom: 2px solid transparent;
    }
    .nav-menu a:hover {
      color: var(--primary);
    }
    .nav-menu a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--dark);
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 1.5rem;
        box-shadow: 0 10px 20px rgba(0,0,0,0.08);
        border-radius: 0 0 16px 16px;
      }
      .nav-menu.active-mobile {
        display: flex;
      }
      .hamburger {
        display: block;
      }
    }
    /* Hero */
    .hero {
      padding: 120px 0 80px;
      display: flex;
      align-items: center;
      gap: 2rem;
      background-color: var(--bg);
      position: relative;
      overflow: hidden;
    }
    .hero-left {
      flex: 1 1 55%;
      z-index: 2;
    }
    .hero-right {
      flex: 1 1 45%;
      position: relative;
      min-height: 360px;
      border-radius: 24px;
      overflow: hidden;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      box-shadow: 0 20px 40px rgba(0,0,0,0.15);
    }
    .hero-right::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(255,77,0,0.25) 0%, rgba(0,229,255,0.1) 100%);
    }
    .hero h1 {
      font-family: var(--font-title);
      font-weight: 900;
      font-size: clamp(2.8rem, 6vw, 4rem);
      color: var(--dark);
      line-height: 1.2;
      margin-bottom: 1.2rem;
    }
    .hero .subtitle {
      font-size: 1.25rem;
      color: var(--muted);
      margin-bottom: 2rem;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: all 0.25s;
      box-shadow: 0 4px 12px rgba(255,77,0,0.25);
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(255,77,0,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: all 0.25s;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      transform: translateY(-2px);
    }
    @media (max-width: 768px) {
      .hero {
        flex-direction: column;
        padding: 100px 20px 60px;
      }
      .hero-right {
        width: 100%;
        min-height: 260px;
        order: -1;
      }
    }
    /* 通用区块 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-family: var(--font-title);
      font-weight: 800;
      font-size: 2.2rem;
      margin-bottom: 2.5rem;
      text-align: center;
      color: var(--dark);
    }
    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--card-shadow);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      border: 1px solid var(--border-light);
    }
    .feature-card:nth-child(2) {
      transform: translateY(-10px);
    }
    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--card-shadow-hover);
    }
    .feature-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 1.25rem;
    }
    .feature-card h3 {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 1.4rem;
      margin-bottom: 0.5rem;
    }
    .feature-card p {
      color: var(--muted);
    }
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
      .feature-card:nth-child(2) {
        transform: none;
      }
    }
    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .service-item {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: all 0.3s;
      display: flex;
      flex-direction: column;
    }
    .service-img {
      height: 180px;
      background-size: cover;
      background-position: center;
      position: relative;
      transition: transform 0.4s;
    }
    .service-item:hover .service-img {
      transform: scale(1.05);
    }
    .service-item:hover {
      box-shadow: var(--card-shadow-hover);
    }
    .service-content {
      padding: 1.5rem;
    }
    .service-content h3 {
      font-weight: 700;
      font-size: 1.2rem;
      margin-bottom: 0.3rem;
    }
    .service-content p {
      color: var(--muted);
      font-size: 0.95rem;
    }
    @media (max-width: 1024px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 576px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 数据看板 */
    .data-panel {
      background: var(--dark);
      border-radius: 24px;
      padding: 48px 24px;
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 20px;
      text-align: center;
      color: white;
    }
    .stat-item .stat-number {
      font-family: var(--font-number);
      font-size: 3rem;
      font-weight: 700;
      color: var(--primary);
      line-height: 1;
    }
    .stat-unit {
      font-size: 1rem;
      color: var(--muted);
      margin-left: 2px;
    }
    .stat-label {
      font-size: 0.9rem;
      color: #aaa;
      margin-top: 0.5rem;
    }
    @media (max-width: 768px) {
      .data-panel {
        grid-template-columns: repeat(3, 1fr);
      }
    }
    @media (max-width: 520px) {
      .data-panel {
        grid-template-columns: 1fr 1fr;
      }
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--dark);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.3s;
      color: var(--muted);
      font-size: 1rem;
      line-height: 1.6;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-top: 0.8rem;
    }
    .faq-icon {
      font-size: 1.3rem;
      color: var(--primary);
    }
    /* CTA */
    .cta-section {
      background: var(--dark);
      color: white;
      padding: 80px 0;
    }
    .cta-form {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-top: 2rem;
      justify-content: center;
    }
    .cta-form input {
      background: rgba(255,255,255,0.1);
      border: 1px solid #444;
      border-radius: var(--radius-input);
      padding: 12px 16px;
      color: white;
      flex: 1 1 200px;
      transition: border 0.2s;
    }
    .cta-form input:focus {
      border-color: var(--accent);
    }
    .btn-accent {
      background: var(--accent);
      color: var(--dark);
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      cursor: pointer;
      transition: 0.25s;
    }
    .btn-accent:hover {
      box-shadow: 0 0 20px rgba(0,229,255,0.5);
    }
    /* 页脚 */
    .footer {
      background: var(--dark);
      color: #999;
      padding: 32px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      border-top: 1px solid #333;
    }
    .footer a {
      color: var(--primary);
    }