/* roulang page: index */
:root {
      --primary: #1B2A4A;
      --primary-light: #2A3F5E;
      --accent: #C9A96E;
      --accent-hover: #B8944F;
      --surface: #FFFFFF;
      --bg-light: #F4F7FA;
      --bg-cool: #D9E2EC;
      --text-primary: #1E1E1E;
      --text-secondary: #4A4A4A;
      --text-muted: #6B7280;
      --text-on-dark: #FFFFFF;
      --border-light: #D9E2EC;
      --shadow-card: 0 8px 24px rgba(0, 0, 0, 0.06);
      --shadow-hover: 0 12px 32px rgba(0, 0, 0, 0.10);
      --radius-card: 16px;
      --radius-btn: 30px;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --transition: 0.3s ease;
    }

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

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

    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      font-weight: 600;
      color: var(--primary);
    }

    h1 {
      font-size: clamp(2.4rem, 5vw, 3.2rem);
      font-weight: 700;
      line-height: 1.3;
      color: #FFFFFF;
    }

    h2 {
      font-size: clamp(1.8rem, 4vw, 2.2rem);
      margin-bottom: 0.5rem;
      letter-spacing: -0.3px;
    }

    h3 {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 0.5rem;
    }

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

    a:hover {
      color: var(--accent);
    }

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 5vw;
    }

    .section {
      padding: 5rem 0;
    }

    @media (max-width: 640px) {
      .section {
        padding: 3rem 0;
      }
    }

    /* 按钮 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 0.85rem 2.4rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      transition: all var(--transition);
      cursor: pointer;
      border: 1px solid transparent;
      text-align: center;
      line-height: 1.2;
    }

    .btn-primary {
      background-color: var(--accent);
      color: var(--primary);
      border: 1px solid var(--accent);
    }

    .btn-primary:hover {
      background-color: var(--accent-hover);
      border-color: var(--accent-hover);
      color: var(--primary);
      transform: translateY(-2px);
      box-shadow: 0 8px 16px rgba(201, 169, 110, 0.25);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
    }

    .btn-outline:hover {
      background: var(--primary);
      color: #FFFFFF;
      border-color: var(--primary);
    }

    .btn-light {
      background: rgba(255,255,255,0.15);
      backdrop-filter: blur(6px);
      border: 1px solid rgba(255,255,255,0.3);
      color: #FFFFFF;
    }

    .btn-light:hover {
      background: rgba(255,255,255,0.28);
      color: #FFFFFF;
    }

    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      z-index: 50;
      display: flex;
      align-items: center;
    }

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

    .logo {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 1.6rem;
      color: var(--primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 0.3rem;
    }

    .logo i {
      color: var(--accent);
      font-size: 1.8rem;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-menu a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-primary);
      position: relative;
      padding: 0.2rem 0;
    }

    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }

    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      font-size: 1.6rem;
      background: none;
      border: none;
      color: var(--primary);
      cursor: pointer;
    }

    /* 移动端底部Tab */
    .mobile-tab-bar {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background: #FFFFFF;
      box-shadow: 0 -4px 12px rgba(0,0,0,0.04);
      z-index: 60;
      justify-content: space-around;
      align-items: center;
      padding: 0 1rem;
    }

    .tab-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: var(--text-muted);
      font-size: 0.7rem;
      transition: color var(--transition);
      cursor: pointer;
    }

    .tab-item i {
      font-size: 1.3rem;
      margin-bottom: 2px;
    }

    .tab-item.active {
      color: var(--accent);
      font-weight: 600;
    }

    @media (max-width: 1024px) {
      .nav-menu {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .mobile-tab-bar {
        display: flex;
      }
      .site-header {
        height: 64px;
      }
    }

    /* 汉堡全屏菜单 */
    .mobile-overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(27, 42, 74, 0.97);
      backdrop-filter: blur(16px);
      z-index: 100;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2rem;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.3s;
    }

    .mobile-overlay.open {
      opacity: 1;
      pointer-events: auto;
    }

    .mobile-overlay a {
      color: #FFFFFF;
      font-size: 1.5rem;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.2);
      padding-bottom: 0.5rem;
    }

    .close-overlay {
      position: absolute;
      top: 20px;
      right: 25px;
      background: none;
      border: none;
      color: #FFFFFF;
      font-size: 2rem;
      cursor: pointer;
    }

    /* Hero */
    .hero {
      background: linear-gradient(180deg, rgba(27,42,74,0.75) 0%, rgba(27,42,74,0.92) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      margin-top: 72px;
    }

    .hero-content {
      max-width: 620px;
      color: #FFFFFF;
    }

    .hero-content p {
      font-size: 1.15rem;
      color: rgba(255,255,255,0.85);
      margin: 1.2rem 0 2rem;
    }

    .constellation {
      position: absolute;
      right: 5%;
      top: 30%;
      width: 280px;
      height: 280px;
      opacity: 0.5;
    }

    @media (max-width: 640px) {
      .hero {
        min-height: 85vh;
      }
      .constellation {
        display: none;
      }
    }

    /* 核心优势非对称 */
    .advantage-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
      align-items: start;
    }

    .adv-large {
      background: var(--surface);
      border-radius: var(--radius-card);
      padding: 2.2rem;
      box-shadow: var(--shadow-card);
    }

    .adv-small-stack {
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
    }

    .adv-card {
      background: var(--surface);
      border-radius: var(--radius-card);
      padding: 1.6rem;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
    }

    .adv-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .adv-icon {
      font-size: 2.2rem;
      color: var(--accent);
      margin-bottom: 1rem;
    }

    @media (max-width: 768px) {
      .advantage-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 服务卡片网格 特色宽卡 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.8rem;
    }

    .service-card {
      background: var(--surface);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      cursor: pointer;
    }

    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-5px);
    }

    .service-card.featured {
      grid-column: span 2;
      display: flex;
      flex-direction: row;
    }

    .service-card.featured .card-img {
      width: 45%;
      height: auto;
      object-fit: cover;
    }

    .card-img {
      height: 200px;
      width: 100%;
      object-fit: cover;
    }

    .card-body {
      padding: 1.5rem;
    }

    @media (max-width: 900px) {
      .service-grid {
        grid-template-columns: 1fr 1fr;
      }
      .service-card.featured {
        grid-column: span 2;
      }
    }

    @media (max-width: 640px) {
      .service-grid {
        grid-template-columns: 1fr;
      }
      .service-card.featured {
        grid-column: span 1;
        flex-direction: column;
      }
      .service-card.featured .card-img {
        width: 100%;
        height: 200px;
      }
    }

    /* 数据滚动 */
    .stats-bar {
      background: var(--bg-light);
      border-radius: 20px;
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      padding: 2rem 1rem;
      margin: 2rem 0;
    }

    .stat-item {
      text-align: center;
    }

    .stat-number {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }

    /* 案例卡片 */
    .case-card {
      display: flex;
      background: var(--surface);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      margin-bottom: 2rem;
    }

    .case-img {
      width: 40%;
      object-fit: cover;
    }

    .case-text {
      padding: 2rem;
      width: 60%;
    }

    @media (max-width: 768px) {
      .case-card {
        flex-direction: column;
      }
      .case-img, .case-text {
        width: 100%;
      }
    }

    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
      text-align: center;
      gap: 1rem;
    }

    .step {
      flex: 1;
      background: var(--surface);
      padding: 1.8rem 1rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      position: relative;
    }

    .step-num {
      width: 40px;
      height: 40px;
      background: var(--accent);
      color: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      margin: 0 auto 1rem;
    }

    @media (max-width: 640px) {
      .steps {
        flex-direction: column;
      }
    }

    /* FAQ */
    .accordion-item {
      background: var(--bg-light);
      border-radius: 10px;
      margin-bottom: 0.8rem;
      overflow: hidden;
    }

    .accordion-header {
      padding: 1rem 1.4rem;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #F4F7FA;
      transition: 0.2s;
    }

    .accordion-header.active {
      color: var(--accent);
    }

    .accordion-content {
      padding: 0 1.4rem 1.2rem;
      display: none;
      color: var(--text-secondary);
    }

    .accordion-content.open {
      display: block;
    }

    /* CTA */
    .dark-cta {
      background: var(--primary);
      color: #FFFFFF;
      text-align: center;
      padding: 4rem 1rem;
      border-radius: 24px;
    }

    /* Footer */
    .site-footer {
      background: var(--primary);
      color: #D9E2EC;
      padding: 3rem 0 1.5rem;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 2rem;
    }

    .copyright {
      border-top: 1px solid rgba(255,255,255,0.12);
      margin-top: 2rem;
      padding-top: 1.2rem;
      font-size: 0.85rem;
      color: #8899AA;
      text-align: center;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }