/* roulang page: index */
/* 设计变量与全局样式 */
    :root {
      --primary: #1A1A2E;
      --accent: #E85D04;
      --bg-light: #F8F9FA;
      --bg-alt: #F4F4F9;
      --text-dark: #2D2D3A;
      --text-muted: #6B6B7B;
      --text-footer: #B0B0C0;
      --border-light: #E0E0E0;
      --white: #FFFFFF;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 4px;
      --radius-tag: 20px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 12px 32px rgba(0,0,0,0.1);
      --shadow-btn: 0 4px 12px rgba(232,93,4,0.3);
      --transition-smooth: 200ms ease;
      --transition-bounce: 300ms ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      color: var(--text-dark);
      background-color: var(--white);
      line-height: 1.7;
      margin: 0;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-smooth);
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 56px;
      z-index: 50;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding-left: 24px;
      padding-right: 24px;
      background: rgba(255,255,255,0.7);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      transition: background var(--transition-bounce), box-shadow var(--transition-bounce);
    }
    .navbar.scrolled {
      background: var(--white);
      box-shadow: 0 2px 16px rgba(0,0,0,0.06);
    }
    .logo-wrapper {
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      background: var(--primary);
      width: 28px;
      height: 28px;
      border-radius: 4px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      font-size: 16px;
      position: relative;
    }
    .logo-icon span {
      position: relative;
      z-index: 2;
    }
    .logo-text {
      font-weight: 700;
      font-size: 20px;
      color: var(--text-dark);
      letter-spacing: -0.3px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-dark);
      position: relative;
      padding-bottom: 4px;
      transition: color var(--transition-smooth);
    }
    .nav-link:hover {
      color: var(--accent);
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition-smooth);
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .cta-btn-nav {
      background: var(--accent);
      color: white;
      padding: 8px 20px;
      border-radius: var(--radius-btn);
      font-size: 14px;
      font-weight: 600;
      transition: background var(--transition-smooth), transform var(--transition-smooth);
      display: inline-block;
      white-space: nowrap;
    }
    .cta-btn-nav:hover {
      background: #C94D00;
      transform: scale(1.03);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 4px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      transition: var(--transition-smooth);
    }
    .mobile-menu {
      position: fixed;
      top: 56px;
      left: 0;
      width: 100%;
      height: calc(100vh - 56px);
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(12px);
      display: none;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      opacity: 0;
      transition: opacity 0.3s ease;
      z-index: 40;
    }
    .mobile-menu.open {
      display: flex;
      opacity: 1;
    }
    @media (max-width: 768px) {
      .nav-links, .cta-btn-nav.desktop-only {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .navbar {
        padding-left: 16px;
        padding-right: 16px;
      }
    }

    /* Hero 区域 */
    .hero-section {
      min-height: calc(100vh - 56px);
      margin-top: 56px;
      display: flex;
      align-items: center;
    }
    .hero-grid {
      display: flex;
      width: 100%;
      min-height: inherit;
    }
    .hero-left {
      width: 50%;
      display: flex;
      align-items: center;
      padding-left: 80px;
      padding-right: 40px;
    }
    .hero-right {
      width: 50%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      overflow: hidden;
    }
    .hero-overlay {
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: linear-gradient(135deg, rgba(26,26,46,0.8) 0%, rgba(232,93,4,0.2) 100%);
    }
    .floating-shape {
      position: absolute;
      background: rgba(255,255,255,0.15);
      border-radius: 50%;
      animation: float 8s infinite ease-in-out;
    }
    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-20px); }
      100% { transform: translateY(0px); }
    }
    .hero-title {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--text-dark);
      margin-bottom: 16px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 90%;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      background: transparent;
      transition: all var(--transition-smooth);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .btn-solid {
      background: var(--accent);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all var(--transition-smooth);
      border: none;
    }
    .btn-solid:hover {
      background: #C94D00;
      box-shadow: var(--shadow-btn);
      transform: scale(1.03);
    }
    @media (max-width: 1024px) {
      .hero-left {
        width: 60%;
        padding-left: 40px;
      }
      .hero-right {
        width: 40%;
      }
      .hero-title {
        font-size: 40px;
      }
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-left, .hero-right {
        width: 100%;
      }
      .hero-left {
        padding: 40px 24px;
        order: 1;
      }
      .hero-right {
        height: 280px;
        order: 2;
      }
      .hero-title {
        font-size: 32px;
      }
      .hero-sub {
        font-size: 16px;
      }
    }

    /* 区块标题 */
    .section-title {
      font-size: 36px;
      font-weight: 600;
      text-align: center;
      margin-bottom: 16px;
      color: var(--text-dark);
    }
    .title-decoration {
      width: 40px;
      height: 4px;
      background: var(--accent);
      margin: 0 auto 48px;
    }
    @media (max-width: 768px) {
      .section-title {
        font-size: 26px;
      }
    }

    /* 核心优势卡片 */
    .adv-card {
      background: var(--white);
      border-top: 4px solid var(--primary);
      padding: 32px;
      transition: transform var(--transition-smooth);
    }
    .adv-icon {
      font-size: 48px;
      color: var(--primary);
      margin-bottom: 16px;
    }

    /* 解决方案交错 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }
    .solution-img {
      width: 50%;
      border-radius: var(--radius-card);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }
    .solution-img:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    @media (max-width: 768px) {
      .solution-row {
        flex-direction: column;
      }
      .solution-img {
        width: 100%;
      }
    }

    /* 案例横向滚动 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scroll-snap-type: x mandatory;
    }
    .case-card {
      min-width: 280px;
      max-width: 320px;
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      scroll-snap-align: start;
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      flex-shrink: 0;
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    .case-img {
      aspect-ratio: 16/9;
      object-fit: cover;
      border-radius: 12px 12px 0 0;
    }
    .tag {
      background: rgba(26,26,46,0.08);
      color: var(--primary);
      padding: 4px 12px;
      border-radius: var(--radius-tag);
      font-size: 13px;
      font-weight: 500;
    }
    .data-highlight {
      color: var(--accent);
      font-weight: 700;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      align-items: center;
      gap: 12px;
      cursor: pointer;
      font-weight: 600;
      font-size: 16px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding-left: 36px;
      color: #4A4A4A;
      font-size: 15px;
    }

    /* 表单 */
    .input-line {
      width: 100%;
      padding: 12px 0;
      border: none;
      border-bottom: 1px solid var(--border-light);
      background: transparent;
      font-size: 16px;
      transition: border 0.2s;
    }
    .input-line:focus {
      outline: none;
      border-bottom: 2px solid var(--primary);
    }
    .submit-btn {
      background: var(--accent);
      color: white;
      width: 100%;
      padding: 14px;
      border: none;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: background 0.2s, box-shadow 0.2s;
    }
    .submit-btn:hover {
      background: #C94D00;
      box-shadow: var(--shadow-btn);
    }

    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }