/* roulang page: index */
/* ----- 设计变量与全局重置 ----- */
    :root {
      --primary: #00A86B;
      --primary-deep: #008A5A;
      --secondary: #1A1A2E;
      --accent: #F0C45A;
      --bg-light: #F8F9FA;
      --card-white: #FFFFFF;
      --text-primary: #1E293B;
      --text-secondary: #64748B;
      --border-light: #E2E8F0;
      --border-subtle: #F1F5F9;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,168,107,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition: 0.25s cubic-bezier(0.2, 0.0, 0.0, 1.0);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "Inter", "SF Pro Display", sans-serif;
      --container-max: 1280px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 标题层级强制规范 */
    h1 {
      font-size: clamp(48px, 8vw, 64px);
      font-weight: 800;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }
    h2 {
      font-size: clamp(36px, 6vw, 42px);
      font-weight: 700;
      margin-bottom: 20px;
      letter-spacing: -0.2px;
    }
    h3 {
      font-size: clamp(20px, 3vw, 24px);
      font-weight: 600;
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-family: var(--font-number);
      transition: var(--transition);
      cursor: pointer;
      border: none;
      background: transparent;
      letter-spacing: 0.3px;
      white-space: nowrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      box-shadow: 0 8px 20px rgba(0,168,107,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      transform: translateY(-2px);
      box-shadow: 0 14px 28px rgba(0,168,107,0.25);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }
    .btn-outline:hover {
      background: rgba(0,168,107,0.08);
      border-color: var(--primary-deep);
      color: var(--primary-deep);
    }
    .btn-accent {
      background: var(--accent);
      color: #1A1A2E;
      font-weight: 700;
      box-shadow: 0 8px 18px rgba(240,196,90,0.25);
      transition: all 0.2s;
    }
    .btn-accent:hover {
      transform: scale(1.03);
      box-shadow: 0 12px 24px rgba(240,196,90,0.4);
      background: #FFD966;
    }

    /* ----- 导航系统 ----- */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: background 0.3s, backdrop-filter 0.3s;
      background: transparent;
    }
    #header.scrolled {
      background: rgba(26, 26, 46, 0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.2);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: white;
      letter-spacing: 1px;
      background: linear-gradient(135deg, #ffffff 0%, #e0f2e9 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 16px;
      transition: color 0.2s;
      position: relative;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--accent);
    }
    .nav-cta-mobile {
      display: none;
    }

    /* 移动端汉堡菜单 */
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      width: 25px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }

    /* ----- Hero 区块 ----- */
    #hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #0F172A 0%, #1A1A2E 70%);
      position: relative;
      overflow: hidden;
      color: white;
    }
    .hero-bg-image {
      position: absolute;
      right: 0;
      top: 0;
      width: 55%;
      height: 100%;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.35;
      mask-image: linear-gradient(to left, rgba(0,0,0,0.9) 0%, rgba(0,0,0,0) 100%);
      -webkit-mask-image: linear-gradient(to left, rgba(0,0,0,0.9) 0%, rgba(0,0,0,0) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
      padding: 40px 0;
    }
    .hero-badge {
      display: inline-block;
      background: rgba(240,196,90,0.15);
      color: var(--accent);
      padding: 6px 16px;
      border-radius: 30px;
      font-weight: 600;
      margin-bottom: 24px;
      letter-spacing: 0.5px;
    }
    .hero-subtitle {
      font-size: 1.25rem;
      color: rgba(255,255,255,0.8);
      margin: 24px 0 32px;
      max-width: 550px;
    }
    .hero-actions {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
      margin-bottom: 40px;
    }
    .trust-badge {
      display: flex;
      align-items: center;
      gap: 12px;
      color: #CBD5E1;
      font-size: 0.95rem;
    }
    .trust-badge i {
      color: var(--accent);
    }

    /* ----- 通用板块 ----- */
    section {
      padding: 100px 0;
    }
    .section-header {
      text-align: center;
      margin-bottom: 60px;
    }
    .section-header p {
      color: var(--text-secondary);
      max-width: 600px;
      margin: 16px auto 0;
      font-size: 1.1rem;
    }

    /* 核心优势 features */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .feature-card {
      background: var(--card-white);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-subtle);
      transition: var(--transition);
    }
    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(0,168,107,0.3);
    }
    .feature-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 20px;
    }

    /* 数据背书 stats */
    #stats {
      background: var(--secondary);
      color: white;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 30px;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent);
    }

    /* 服务矩阵 非对称布局 */
    .services-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .service-main-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 40px;
      box-shadow: var(--shadow-sm);
      grid-row: span 2;
      display: flex;
      flex-direction: column;
      justify-content: center;
      background-image: url('/assets/images/coverpic/cover-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      color: white;
      overflow: hidden;
    }
    .service-main-card::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(0deg, rgba(0,0,0,0.75) 0%, rgba(0,0,0,0.2) 70%);
    }
    .service-main-content {
      position: relative;
      z-index: 2;
      margin-top: auto;
    }
    .service-sub-card {
      background: var(--card-white);
      padding: 28px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      display: flex;
      gap: 20px;
      align-items: center;
      transition: var(--transition);
    }
    .service-sub-card:hover {
      box-shadow: var(--shadow-hover);
    }

    /* 案例网格 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }
    .case-card img {
      border-radius: var(--radius-card);
      aspect-ratio: 16/9;
      object-fit: cover;
    }

    /* FAQ */
    .faq-item {
      background: var(--card-white);
      border-left: 4px solid var(--primary);
      margin-bottom: 16px;
      border-radius: 0 var(--radius-card) var(--radius-card) 0;
      transition: 0.2s;
    }
    .faq-question {
      padding: 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 24px 24px;
      color: var(--text-secondary);
      display: none;
    }
    .faq-item.active {
      border-left-color: var(--accent);
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA 深色区 */
    #cta {
      background: var(--secondary);
      text-align: center;
      color: white;
    }

    /* Footer */
    #footer {
      background: #0B0B1A;
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
    }

    /* 响应式设计 */
    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: repeat(2,1fr); }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .services-layout { grid-template-columns: 1fr; }
      .cases-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .hero-bg-image { width: 100%; opacity: 0.2; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 520px) {
      .features-grid, .stats-grid { grid-template-columns: 1fr; }
      .hero-actions { flex-direction: column; }
    }