/* roulang page: index */
:root {
      --lemon-yellow: #F5C518;
      --deep-navy: #1A1A2E;
      --midnight-blue: #0F3460;
      --warm-white: #FAFAFA;
      --sport-red: #E63946;
      --text-primary: #1A1A2E;
      --text-secondary: #4A4A5A;
      --border-light: #EBEBEB;
      --card-shadow: 0 2px 12px rgba(0,0,0,0.04);
      --card-hover-shadow: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Inter', system-ui, -apple-system, sans-serif;
      --transition-smooth: all 0.3s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--warm-white);
      color: var(--text-primary);
      line-height: 1.8;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .container-custom {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 导航栏 */
    .navbar-lemon {
      background-color: var(--deep-navy);
      padding: 12px 0;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1050;
      box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    }
    .navbar-brand-custom {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 1.5rem;
      color: white;
      letter-spacing: 1px;
    }
    .navbar-brand-custom i {
      font-size: 1.8rem;
      color: var(--lemon-yellow);
    }
    .nav-link-lemon {
      color: rgba(255,255,255,0.85) !important;
      font-weight: 500;
      margin: 0 10px;
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: var(--transition-smooth);
    }
    .nav-link-lemon:hover,
    .nav-link-lemon.active {
      color: var(--lemon-yellow) !important;
      border-bottom-color: var(--lemon-yellow);
    }
    .navbar-toggler {
      border: none;
      color: white;
      font-size: 1.5rem;
    }
    .offcanvas-lemon {
      background-color: var(--deep-navy);
      color: white;
    }
    .offcanvas-lemon .nav-link {
      color: white;
      font-size: 1.2rem;
      padding: 12px 20px;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .offcanvas-lemon .nav-link:hover {
      color: var(--lemon-yellow);
    }

    /* 底部移动Tab */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: var(--deep-navy);
      z-index: 1040;
      box-shadow: 0 -2px 8px rgba(0,0,0,0.1);
      justify-content: space-around;
      padding: 8px 0;
    }
    .mobile-tab {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: rgba(255,255,255,0.7);
      font-size: 0.7rem;
      transition: var(--transition-smooth);
    }
    .mobile-tab i {
      font-size: 1.3rem;
      margin-bottom: 2px;
    }
    .mobile-tab.active {
      color: var(--lemon-yellow);
    }

    /* Hero */
    .hero-section {
      height: 100vh;
      min-height: 600px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
    }
    .hero-overlay {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: linear-gradient(135deg, rgba(26,26,46,0.65) 0%, rgba(15,52,96,0.5) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      color: white;
      max-width: 800px;
      padding: 0 20px;
    }
    .hero-title {
      font-size: 3.5rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 1.2rem;
    }
    .hero-sub {
      font-size: 1.25rem;
      opacity: 0.9;
      margin-bottom: 2rem;
    }
    .btn-lemon-primary {
      background: var(--lemon-yellow);
      border: none;
      color: var(--deep-navy);
      font-weight: 600;
      padding: 12px 30px;
      border-radius: var(--radius-btn);
      transition: var(--transition-smooth);
    }
    .btn-lemon-primary:hover {
      background: var(--deep-navy);
      color: white;
    }
    .btn-outline-white {
      border: 1px solid white;
      color: white;
      background: transparent;
      padding: 12px 30px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-smooth);
    }
    .btn-outline-white:hover {
      background: rgba(255,255,255,0.1);
      border-color: var(--lemon-yellow);
      color: var(--lemon-yellow);
    }
    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      color: var(--lemon-yellow);
      font-size: 2rem;
      animation: bounce 2s infinite;
      z-index: 3;
    }
    @keyframes bounce {
      0%, 100% { transform: translateX(-50%) translateY(0); }
      50% { transform: translateX(-50%) translateY(8px); }
    }

    /* 通用区块 */
    .section-padding {
      padding: 80px 0;
    }
    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      margin-bottom: 1rem;
      color: var(--deep-navy);
    }
    .section-subtitle {
      color: var(--text-secondary);
      max-width: 700px;
      margin: 0 auto 3rem;
    }

    /* 服务卡片2x2非对称 */
    .service-card {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--card-shadow);
      transition: var(--transition-smooth);
      height: 100%;
      display: flex;
      flex-direction: column;
      position: relative;
    }
    .service-card:hover {
      box-shadow: var(--card-hover-shadow);
      transform: translateY(-4px);
    }
    .service-icon {
      font-size: 2.5rem;
      color: var(--lemon-yellow);
      margin-bottom: 1.2rem;
    }
    .service-card h3 {
      font-weight: 700;
      font-size: 1.4rem;
      margin-bottom: 0.8rem;
    }
    .service-link {
      margin-top: auto;
      font-weight: 600;
      color: var(--deep-navy);
      display: inline-block;
      border-bottom: 2px solid transparent;
      transition: var(--transition-smooth);
    }
    .service-link:hover {
      border-bottom-color: var(--lemon-yellow);
      color: var(--lemon-yellow);
    }
    .extra-tag {
      background: var(--lemon-yellow);
      color: var(--deep-navy);
      font-size: 0.7rem;
      font-weight: 700;
      padding: 2px 10px;
      border-radius: 20px;
      position: absolute;
      top: 16px;
      right: 16px;
    }

    /* 数据指标 */
    .data-metric {
      text-align: center;
      padding: 1.5rem;
    }
    .data-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--lemon-yellow);
      font-family: 'Inter', sans-serif;
    }
    .data-divider {
      width: 60px;
      height: 2px;
      background: var(--border-light);
      margin: 1rem auto;
    }

    /* 案例卡片左右交替 */
    .case-card {
      display: flex;
      align-items: center;
      margin-bottom: 3rem;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--card-shadow);
    }
    .case-img {
      width: 45%;
      object-fit: cover;
      height: 260px;
      border-radius: var(--radius-card) 0 0 var(--radius-card);
    }
    .case-text {
      padding: 2rem;
      width: 55%;
    }
    .case-tag {
      background: var(--lemon-yellow);
      color: var(--deep-navy);
      font-size: 0.75rem;
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 0.8rem;
    }
    .flex-row-reverse .case-img {
      border-radius: 0 var(--radius-card) var(--radius-card) 0;
    }

    /* 解决方案流程 */
    .step-list {
      list-style: none;
      padding: 0;
    }
    .step-item {
      display: flex;
      align-items: baseline;
      gap: 15px;
      margin-bottom: 1.8rem;
      cursor: pointer;
      font-weight: 600;
      color: var(--text-secondary);
      transition: var(--transition-smooth);
    }
    .step-num {
      width: 36px;
      height: 36px;
      background: var(--border-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
    }
    .step-item.active .step-num {
      background: var(--lemon-yellow);
      color: var(--deep-navy);
    }
    .detail-card {
      background: white;
      padding: 2rem;
      border-radius: var(--radius-card);
      border-left: 5px solid var(--lemon-yellow);
      box-shadow: var(--card-shadow);
    }

    /* FAQ */
    .accordion-button:not(.collapsed) {
      background-color: #fff9e6;
      color: var(--deep-navy);
      font-weight: 600;
    }
    .accordion-button:focus {
      box-shadow: none;
      border-color: var(--lemon-yellow);
    }
    .accordion-item {
      border: 1px solid var(--border-light);
      margin-bottom: 0.8rem;
      border-radius: var(--radius-card);
    }

    /* CTA横幅 */
    .cta-banner {
      background: linear-gradient(135deg, var(--deep-navy) 0%, var(--midnight-blue) 100%);
      padding: 4rem 0;
      text-align: center;
      color: white;
    }
    .btn-cta-red {
      background: var(--sport-red);
      border: none;
      color: white;
      font-weight: 700;
      padding: 14px 35px;
      border-radius: var(--radius-btn);
      transition: var(--transition-smooth);
    }
    .btn-cta-red:hover {
      background: var(--lemon-yellow);
      color: var(--deep-navy);
    }

    /* 页脚 */
    .footer-lemon {
      background: var(--deep-navy);
      color: rgba(255,255,255,0.8);
      padding: 3rem 0 1.5rem;
    }
    .social-icon {
      display: inline-flex;
      width: 36px;
      height: 36px;
      background: rgba(255,255,255,0.1);
      border-radius: 50%;
      align-items: center;
      justify-content: center;
      margin-right: 8px;
      transition: var(--transition-smooth);
    }
    .social-icon:hover {
      background: var(--lemon-yellow);
      color: var(--deep-navy);
    }

    @media (max-width: 992px) {
      .hero-title { font-size: 2.8rem; }
      .case-card { flex-direction: column; }
      .case-img, .flex-row-reverse .case-img { width: 100%; height: 220px; border-radius: var(--radius-card) var(--radius-card) 0 0; }
      .case-text { width: 100%; }
    }
    @media (max-width: 768px) {
      .mobile-bottom-nav { display: flex; }
      .navbar-lemon .navbar-nav { display: none; }
      .hero-title { font-size: 2.2rem; }
      .section-title { font-size: 1.8rem; }
      .data-number { font-size: 2.2rem; }
    }
    @media (max-width: 576px) {
      .hero-title { font-size: 1.8rem; }
    }