/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --primary-deep: #0B1E2E;
      --accent-gold: #C8A96E;
      --accent-gold-hover: #B8995A;
      --bg-light: #FAFAFA;
      --card-white: #FFFFFF;
      --text-dark: #1E293B;
      --text-body: #333333;
      --text-muted: #666666;
      --text-light: #CCCCCC;
      --border-light: #E5E7EB;
      --shadow-sm: 0 2px 16px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 32px rgba(0,0,0,0.08);
      --shadow-nav: 0 2px 20px rgba(0,0,0,0.06);
      --radius-md: 12px;
      --radius-btn: 8px;
      --transition: 0.3s ease;
      --font-title: 'PingFang SC', 'Noto Sans SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      --font-body: 'PingFang SC', 'Noto Sans SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 板块间距 */
    section {
      padding: 100px 0;
    }

    /* 导航样式 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(12px);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: box-shadow var(--transition);
    }
    .site-header.scrolled {
      box-shadow: var(--shadow-nav);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary-deep);
      text-decoration: none;
      letter-spacing: -0.5px;
    }
    .logo i {
      color: var(--accent-gold);
      font-size: 2rem;
      transform: rotate(45deg);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 36px;
      list-style: none;
    }
    .nav-menu a {
      font-weight: 500;
      color: var(--text-dark);
      font-size: 1rem;
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color var(--transition), border-color var(--transition);
    }
    .nav-menu a:hover {
      color: var(--accent-gold);
      border-bottom-color: var(--accent-gold);
    }
    .btn-cta {
      background: var(--accent-gold);
      color: var(--primary-deep);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      transition: background var(--transition), box-shadow var(--transition);
      white-space: nowrap;
      letter-spacing: 0.3px;
    }
    .btn-cta:hover {
      background: var(--accent-gold-hover);
      box-shadow: 0 0 0 2px rgba(200,169,110,0.5);
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--primary-deep);
      cursor: pointer;
    }
    .mobile-drawer {
      position: fixed;
      top: 0;
      right: -100%;
      width: 80%;
      max-width: 360px;
      height: 100vh;
      background: rgba(11,30,46,0.97);
      backdrop-filter: blur(20px);
      z-index: 2000;
      display: flex;
      flex-direction: column;
      padding: 32px;
      transition: right 0.4s ease;
    }
    .mobile-drawer.open {
      right: 0;
    }
    .drawer-close {
      align-self: flex-end;
      font-size: 2rem;
      color: #fff;
      background: transparent;
      border: none;
      margin-bottom: 40px;
    }
    .drawer-menu {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 28px;
    }
    .drawer-menu a {
      color: #fff;
      font-size: 1.5rem;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.2);
      padding-bottom: 8px;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0B1E2E 0%, #0A1A2B 100%);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      padding: 160px 0 120px;
      color: white;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-text {
      flex: 1 1 55%;
    }
    .hero-graphic {
      flex: 1 1 45%;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .hero h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 24px;
      color: white;
    }
    .hero .sub {
      font-size: 1.125rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 36px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-gold);
      color: var(--primary-deep);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: all var(--transition);
    }
    .btn-outline:hover {
      background: white;
      color: var(--primary-deep);
    }
    .geometric-shape {
      width: 320px;
      height: 320px;
      border: 2px solid rgba(200,169,110,0.4);
      border-radius: 50%;
      position: relative;
      animation: slowSpin 20s infinite linear;
    }
    @keyframes slowSpin {
      from { transform: rotate(0deg); }
      to { transform: rotate(360deg); }
    }

    /* 优势不对称栅格 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 24px;
    }
    .adv-card {
      background: var(--card-white);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
    }
    .adv-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .big-number {
      font-size: 3.5rem;
      font-weight: 800;
      color: var(--accent-gold);
      line-height: 1;
    }

    /* 服务体系 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: white;
      padding: 32px 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      border-bottom: 3px solid transparent;
    }
    .service-card:hover {
      border-bottom-color: var(--accent-gold);
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-icon {
      font-size: 2.2rem;
      color: var(--accent-gold);
      margin-bottom: 16px;
    }

    /* 数据墙 */
    .data-wall {
      background: #F0F0F0;
      background-image: url('/assets/images/backpic/back-2.webp');
      background-blend-mode: overlay;
    }
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
    }

    /* 案例 */
    .case-row {
      display: flex;
      align-items: center;
      gap: 0;
      margin-bottom: 48px;
    }
    .case-img {
      flex: 1 1 50%;
      min-height: 360px;
      background-size: cover;
      background-position: center;
      position: relative;
      border-radius: var(--radius-md) 0 0 var(--radius-md);
    }
    .case-img::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(to right, transparent, rgba(11,30,46,0.7));
    }
    .case-content {
      flex: 1 1 50%;
      background: white;
      padding: 48px;
      border-left: 4px solid var(--accent-gold);
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
    }
    .faq-item {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: white;
      transition: background 0.2s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: #F8F8F8;
      padding: 0 24px;
    }

    /* CTA */
    .cta-dark {
      background: var(--primary-deep);
      position: relative;
      overflow: hidden;
    }
    .particles {
      position: absolute;
      inset: 0;
      pointer-events: none;
    }

    /* 页脚 */
    .footer {
      background: var(--primary-deep);
      color: var(--text-light);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .advantages-grid { grid-template-columns: 1fr 1fr; }
      .services-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      .nav-menu { display: none; }
      .hamburger { display: block; }
      .hero-grid { flex-direction: column; }
      .advantages-grid, .services-grid, .data-grid, .faq-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .case-row { flex-direction: column; }
      .case-img { width: 100%; border-radius: var(--radius-md) var(--radius-md) 0 0; }
    }