/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --primary: #2BA471;      /* 竹青绿 */
      --primary-soft: #F0F8F4;
      --secondary: #1F2329;    /* 墨韵黑 */
      --accent: #FF7D00;       /* 竞技橙 */
      --accent-hover: #E66A00;
      --bg: #F9F9F6;          /* 暖瓷白 */
      --white: #FFFFFF;
      --text: #1F2329;
      --text-soft: #5E646E;
      --border-light: rgba(0,0,0,0.04);
      --shadow-card: 0 8px 30px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 16px 40px rgba(0, 0, 0, 0.08);
      --radius-card: 16px;
      --radius-btn: 40px;
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Inter", sans-serif;
      --transition: all 0.25s ease;
    }

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

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 排版辅助 */
    h1, h2, h3 {
      font-weight: 600;
      letter-spacing: -0.02em;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    /* 导航栏 - 沉浸式模糊效果 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      transition: var(--transition);
      padding: 16px 0;
    }

    .header.scrolled {
      background: rgba(249, 249, 246, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      padding: 10px 0;
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 22px;
      color: var(--secondary);
      letter-spacing: -0.5px;
    }

    .logo-icon {
      display: flex;
      align-items: center;
      justify-content: center;
      background: var(--primary);
      color: white;
      width: 36px;
      height: 36px;
      border-radius: 10px;
      font-size: 20px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-weight: 500;
      font-size: 16px;
      color: var(--secondary);
      transition: color 0.2s;
      position: relative;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--secondary);
      border-radius: 4px;
      transition: var(--transition);
    }

    /* 移动端导航面板 */
    .mobile-menu {
      position: fixed;
      top: 0;
      right: 0;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: rgba(249, 249, 246, 0.98);
      backdrop-filter: blur(20px);
      box-shadow: -8px 0 30px rgba(0,0,0,0.05);
      transform: translateX(100%);
      transition: transform 0.3s ease;
      z-index: 200;
      display: flex;
      flex-direction: column;
      padding: 32px 24px;
    }

    .mobile-menu.active {
      transform: translateX(0);
    }

    .mobile-menu a {
      padding: 16px 0;
      font-size: 18px;
      font-weight: 500;
      border-bottom: 1px solid rgba(0,0,0,0.04);
      color: var(--secondary);
    }

    /* 首屏 Hero */
    .hero {
      padding: 140px 0 80px;
      background: radial-gradient(circle at 80% 30%, rgba(43,164,113,0.05) 0%, transparent 60%);
      position: relative;
      overflow: hidden;
    }

    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-content {
      flex: 1;
    }

    .hero-content h1 {
      font-size: 52px;
      line-height: 1.2;
      margin-bottom: 24px;
      color: var(--secondary);
    }

    .hero-highlight {
      color: var(--primary);
      position: relative;
    }

    .hero-content p {
      font-size: 18px;
      color: var(--text-soft);
      margin-bottom: 36px;
      max-width: 480px;
    }

    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: var(--transition);
      box-shadow: 0 6px 16px rgba(255,125,0,0.25);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 12px 24px rgba(255,125,0,0.35);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
    }

    .btn-outline:hover {
      background: rgba(43,164,113,0.06);
    }

    .hero-visual {
      flex: 1;
      display: flex;
      justify-content: center;
      position: relative;
    }

    .hero-visual img {
      max-height: 420px;
      border-radius: 32px;
      box-shadow: var(--shadow-hover);
    }

    /* 板块通用 */
    .section {
      padding: 90px 0;
    }

    .section-title {
      font-size: 34px;
      margin-bottom: 16px;
      color: var(--secondary);
    }

    .section-sub {
      color: var(--text-soft);
      margin-bottom: 48px;
      font-size: 17px;
    }

    /* 服务区 - 交错布局 */
    .services-grid {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }

    .service-row {
      display: flex;
      gap: 24px;
      align-items: center;
    }

    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      flex: 1;
    }

    .service-card.wide {
      flex: 2;
      background: linear-gradient(135deg, #F0F8F4 0%, #FFFFFF 100%);
      display: flex;
      gap: 24px;
      align-items: center;
    }

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

    .service-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 20px;
    }

    .service-card h3 {
      font-size: 22px;
      margin-bottom: 12px;
    }

    /* 数据徽章 */
    .data-badges {
      background: var(--secondary);
      color: white;
      padding: 70px 0;
    }

    .badge-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 30px;
    }

    .badge-item .number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      font-family: 'Inter', sans-serif;
      letter-spacing: -1px;
    }

    .badge-item span {
      display: block;
      font-size: 16px;
      color: rgba(255,255,255,0.75);
      margin-top: 8px;
    }

    /* 案例卡片 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scroll-snap-type: x mandatory;
    }

    .case-card {
      min-width: 300px;
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      scroll-snap-align: start;
      transition: var(--transition);
    }

    .case-card img {
      border-radius: 16px 16px 0 0;
      height: 180px;
      object-fit: cover;
      width: 100%;
    }

    .case-info {
      padding: 20px;
    }

    .tag {
      background: rgba(43,164,113,0.1);
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.05);
    }

    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      padding: 24px 0;
      font-size: 18px;
      font-weight: 600;
      text-align: left;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--secondary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.3s;
      background: var(--primary-soft);
      border-radius: 12px;
      padding: 0 20px;
      margin-bottom: 8px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 20px;
    }

    /* CTA 块 */
    .cta-block {
      background: var(--accent);
      color: white;
      text-align: center;
      padding: 80px 24px;
      border-radius: 32px;
      margin: 0 24px;
    }

    .footer {
      background: var(--secondary);
      color: rgba(255,255,255,0.7);
      text-align: center;
      padding: 40px 0;
      font-size: 14px;
    }

    @media (max-width: 1024px) {
      .hero .container {
        flex-direction: column;
        text-align: center;
      }
      .hero-content p {
        margin-left: auto;
        margin-right: auto;
      }
      .btn-group {
        justify-content: center;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .service-row {
        flex-direction: column;
      }
      .hero-content h1 {
        font-size: 36px;
      }
    }