/* roulang page: index */
:root {
      --primary-green: #00A859;
      --accent-red: #E60012;
      --deep-gray: #1A1D21;
      --warm-white: #F7F7F2;
      --card-white: #FFFFFF;
      --text-main: #1A1D21;
      --text-secondary: #5A5D61;
      --text-disabled: #B0B3B8;
      --border-light: #E0E0E0;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 12px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --container-max: 1200px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'Noto Sans SC', sans-serif;
      background-color: var(--warm-white);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, .data-number {
      font-family: 'Montserrat', 'Noto Sans SC', sans-serif;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 20px;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    /* 导航 */
    .nav-bar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(26, 29, 33, 0.85);
      backdrop-filter: blur(12px);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: background 0.3s;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .nav-bar.scrolled {
      background: var(--deep-gray);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 20px;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .logo-graphic {
      width: 40px;
      height: 40px;
      position: relative;
    }
    .logo-graphic svg {
      width: 100%;
      height: 100%;
    }
    .logo-text {
      font-family: 'Montserrat', 'Noto Sans SC', sans-serif;
      font-weight: 700;
      font-size: 1.4rem;
      color: white;
      letter-spacing: -0.3px;
    }
    .logo-text span {
      color: var(--primary-green);
      font-weight: 900;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--primary-green);
      transition: width 0.3s;
    }
    .nav-links a:hover {
      color: white;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-cta-nav {
      background: var(--accent-red);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      transition: background 0.25s, transform 0.2s;
    }
    .btn-cta-nav:hover {
      background: #c4000f;
      transform: scale(1.02);
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
    }
    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: var(--deep-gray);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        transform: translateY(-150%);
        transition: transform 0.4s ease;
        box-shadow: 0 10px 20px rgba(0,0,0,0.3);
        z-index: 999;
      }
      .nav-links.active {
        transform: translateY(0);
      }
      .mobile-toggle {
        display: block;
      }
      .btn-cta-nav {
        width: 100%;
        text-align: center;
      }
    }
    /* Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      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;
      color: white;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(180deg, rgba(26,29,33,0.7) 0%, rgba(0,168,89,0.4) 100%);
      backdrop-filter: blur(2px);
    }
    .hero-content {
      position: relative;
      z-index: 10;
      max-width: 850px;
      padding: 0 20px;
    }
    .hero h1 {
      font-size: 48px;
      line-height: 1.2;
      font-weight: 900;
      letter-spacing: -0.5px;
      margin-bottom: 24px;
    }
    .hero .subtitle {
      font-size: 1.3rem;
      color: rgba(255,255,255,0.9);
      margin-bottom: 40px;
      font-weight: 400;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-red);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      transition: 0.25s;
      display: inline-block;
    }
    .btn-primary:hover {
      background: #c4000f;
      transform: scale(1.02);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      transition: 0.25s;
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.15);
    }
    @media (max-width: 768px) {
      .hero h1 { font-size: 36px; }
    }
    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .section-title::before {
      content: '';
      width: 3px;
      height: 32px;
      background: var(--primary-green);
      display: inline-block;
    }
    .section-desc {
      color: var(--text-secondary);
      max-width: 700px;
      margin-bottom: 48px;
      font-size: 1.1rem;
    }
    /* 服务卡片横向 */
    .service-grid {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .service-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      display: flex;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 1px solid var(--border-light);
    }
    .service-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .service-img {
      width: 280px;
      flex-shrink: 0;
      background: #f0f0f0;
    }
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .service-info {
      padding: 32px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .service-info h3 {
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .service-info p {
      color: var(--text-secondary);
      margin-bottom: 16px;
    }
    @media (max-width: 768px) {
      .service-card {
        flex-direction: column;
      }
      .service-img {
        width: 100%;
        height: 200px;
      }
    }
    /* 数据区 */
    .data-strip {
      background: var(--deep-gray);
      color: white;
      padding: 80px 0;
      text-align: center;
    }
    .data-numbers {
      display: flex;
      justify-content: center;
      gap: 60px;
      flex-wrap: wrap;
    }
    .data-item .num {
      font-size: 48px;
      font-weight: 800;
      color: var(--primary-green);
      line-height: 1.2;
    }
    .data-item .label {
      color: #aaa;
    }
    /* 案例瀑布流 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .case-card img {
      height: 220px;
      object-fit: cover;
      width: 100%;
    }
    .case-info {
      padding: 20px;
    }
    .tag {
      background: var(--accent-red);
      color: white;
      font-size: 0.75rem;
      padding: 4px 10px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 8px;
      font-weight: 600;
    }
    @media (max-width: 768px) {
      .case-grid { grid-template-columns: 1fr; }
    }
    /* 时间轴 */
    .timeline {
      position: relative;
      padding-left: 40px;
      border-left: 3px solid var(--primary-green);
    }
    .timeline-item {
      margin-bottom: 40px;
      position: relative;
    }
    .timeline-item::before {
      content: attr(data-step);
      position: absolute;
      left: -57px;
      background: var(--primary-green);
      color: white;
      width: 32px;
      height: 32px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
    }
    /* FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      border: 1px solid var(--border-light);
    }
    .faq-question {
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 20px 20px;
      color: var(--text-secondary);
      display: none;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-item.open {
      background: #f0faf4;
    }
    /* 全局CTA */
    .global-cta {
      background: url('/assets/images/backpic/back-2.webp') center/cover no-repeat;
      padding: 100px 0;
      text-align: center;
      color: white;
      position: relative;
    }
    .global-cta::before {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(26,29,33,0.75);
    }
    .global-cta .container {
      position: relative;
      z-index: 2;
    }
    /* 页脚 */
    footer {
      background: var(--deep-gray);
      color: #ccc;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }