/* roulang page: index */
/* ----- 设计变量 :root ----- */
    :root {
      --primary-green: #5B8C5A;
      --primary-green-hover: #4A7A49;
      --secondary-blue: #4A5B6B;
      --secondary-blue-dark: #3A4856;
      --bg-body: #FAFBF7;
      --bg-light: #EEF2E8;
      --white: #FFFFFF;
      --text-dark: #2C3E35;
      --text-muted: #5F6B7A;
      --text-footer: #BCC7D1;
      --border-light: #E8ECE4;
      --shadow-card: 0 2px 16px rgba(74, 91, 107, 0.08);
      --shadow-card-hover: 0 8px 28px rgba(74, 91, 107, 0.15);
      --radius-card: 12px;
      --radius-button: 8px;
      --radius-dock: 20px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --max-width: 1200px;
      --transition: 0.3s ease;
    }

    /* ----- Reset & Base ----- */
    *, *::before, *::after {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      font-size: 16px;
      font-weight: 400;
      line-height: 1.75;
      color: var(--text-dark);
      background-color: var(--bg-body);
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, .button {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    h1, h2, h3, h4, p {
      margin: 0;
      padding: 0;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* ----- 浮动导航 Dock ----- */
    .float-dock {
      position: fixed;
      top: 16px;
      left: 50%;
      transform: translateX(-50%);
      width: calc(100% - 32px);
      max-width: 1100px;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-radius: var(--radius-dock);
      box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
      padding: 8px 24px;
      z-index: 999;
      display: flex;
      align-items: center;
      justify-content: space-between;
      transition: all var(--transition);
    }

    .logo-area {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo-text {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary-green);
      letter-spacing: -0.5px;
      line-height: 1.2;
    }

    .logo-icon {
      font-size: 28px;
      color: var(--primary-green);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
      margin: 0;
      padding: 0;
    }

    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-dark);
      padding: 6px 2px;
      border-bottom: 2px solid transparent;
      transition: color var(--transition), border-color var(--transition);
    }

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

    .dock-cta {
      background: var(--primary-green);
      color: white;
      padding: 12px 24px;
      border-radius: var(--radius-button);
      font-weight: 600;
      font-size: 15px;
      transition: background var(--transition);
      white-space: nowrap;
    }

    .dock-cta:hover {
      background: var(--primary-green-hover);
    }

    .hamburger {
      display: none;
      font-size: 24px;
      color: var(--secondary-blue);
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
    }

    /* 移动端导航面板 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 80px;
      left: 16px;
      right: 16px;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(20px);
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.15);
      padding: 24px;
      z-index: 1000;
      flex-direction: column;
      gap: 20px;
    }

    .mobile-menu a {
      display: block;
      font-size: 18px;
      font-weight: 600;
      color: var(--secondary-blue);
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }

    .mobile-menu .mobile-cta {
      background: var(--primary-green);
      color: white;
      text-align: center;
      border-radius: 12px;
      padding: 14px;
      margin-top: 8px;
    }

    /* ----- Hero 首屏 ----- */
    .hero {
      padding: 140px 0 80px;
      background: linear-gradient(135deg, #FAFBF7 0%, #EEF2E8 100%);
    }

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

    .hero-left {
      flex: 0 0 55%;
    }

    .hero-right {
      flex: 0 0 45%;
    }

    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--text-dark);
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--secondary-blue);
      margin-bottom: 32px;
      line-height: 1.6;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--primary-green);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-button);
      font-weight: 600;
      font-size: 16px;
      transition: background var(--transition);
    }

    .btn-primary:hover {
      background: var(--primary-green-hover);
    }

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

    .btn-outline:hover {
      background: var(--secondary-blue);
      color: white;
    }

    .hero-img {
      width: 100%;
      border-radius: 20px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.1);
      position: relative;
    }

    .hero-img img {
      border-radius: 20px;
      width: 100%;
      object-fit: cover;
    }

    .img-overlay {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: rgba(91, 140, 90, 0.08);
      border-radius: 20px;
    }

    /* ----- 通用板块标题 ----- */
    .section {
      padding: 80px 0;
    }

    .section h2 {
      font-size: 36px;
      font-weight: 600;
      letter-spacing: -0.3px;
      color: var(--text-dark);
      margin-bottom: 16px;
      text-align: center;
    }

    .section-sub {
      font-size: 18px;
      color: var(--text-muted);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 48px;
    }

    /* 卡片网格 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .feature-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      text-align: left;
    }

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

    .icon-circle {
      font-size: 36px;
      color: var(--primary-green);
      margin-bottom: 20px;
    }

    .feature-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
      color: var(--text-dark);
    }

    .feature-card p {
      font-size: 16px;
      color: var(--text-muted);
      margin-bottom: 20px;
      line-height: 1.6;
    }

    .decor-line {
      width: 40px;
      height: 3px;
      background: var(--primary-green);
      border-radius: 2px;
      margin-top: auto;
    }

    /* 数据背书 Stats */
    .stats-bg {
      background: var(--secondary-blue);
      padding: 70px 0;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }

    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: white;
      line-height: 1.2;
    }

    .stat-label {
      font-size: 16px;
      color: rgba(255,255,255,0.8);
      margin-top: 8px;
    }

    /* 案例卡片 */
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
    }

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

    .case-img-wrap {
      position: relative;
      height: 200px;
      overflow: hidden;
    }

    .case-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .case-overlay {
      position: absolute;
      top: 0; left: 0;
      width: 100%; height: 100%;
      background: rgba(91, 140, 90, 0.5);
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 600;
      font-size: 18px;
      opacity: 0;
      transition: opacity var(--transition);
    }

    .case-card:hover .case-overlay {
      opacity: 1;
    }

    .case-info {
      padding: 20px 24px;
    }

    .case-info h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .tag {
      display: inline-block;
      background: #EEF2E8;
      color: var(--primary-green);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 500;
    }

    /* 解决方案图文 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

    .solution-row.reverse {
      flex-direction: row-reverse;
    }

    .solution-img {
      flex: 0 0 500px;
      border-radius: 20px;
      overflow: hidden;
    }

    .solution-img img {
      width: 100%;
      border-radius: 20px;
    }

    .solution-text h3 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .solution-text p {
      color: var(--text-muted);
      margin-bottom: 20px;
    }

    .solution-list {
      list-style: none;
      padding: 0;
    }

    .solution-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 12px;
      font-size: 16px;
    }

    .solution-list li i {
      color: var(--primary-green);
      font-size: 12px;
    }

    /* FAQ 手风琴 */
    .accordion-item {
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 4px;
    }

    .accordion-title {
      font-size: 18px;
      font-weight: 600;
      color: var(--secondary-blue);
      padding: 18px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: transparent;
      width: 100%;
      text-align: left;
    }

    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-muted);
      font-size: 16px;
      padding-right: 20px;
    }

    .accordion-content.open {
      max-height: 200px;
      padding-bottom: 16px;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary-green);
      padding: 70px 24px;
      text-align: center;
      border-radius: 24px;
      margin: 60px 0;
    }

    .cta-banner h2 {
      color: white;
      font-size: 36px;
    }

    .cta-banner p {
      color: rgba(255,255,255,0.9);
      margin: 16px 0 28px;
    }

    .btn-white-outline {
      border: 2px solid white;
      color: white;
      padding: 14px 36px;
      border-radius: 8px;
      font-weight: 600;
      transition: all 0.3s;
    }

    .btn-white-outline:hover {
      background: white;
      color: var(--primary-green);
    }

    /* 页脚 */
    .footer {
      background: var(--secondary-blue-dark);
      color: var(--text-footer);
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
    }

    .footer h4 {
      color: white;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .footer a {
      color: var(--text-footer);
      display: block;
      margin-bottom: 10px;
    }

    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .card-grid { grid-template-columns: repeat(2, 1fr); }
      .solution-row { flex-direction: column; gap: 30px; }
      .solution-row.reverse { flex-direction: column; }
      .solution-img { flex: 0 0 auto; width: 100%; }
    }

    @media (max-width: 768px) {
      .nav-links, .dock-cta { display: none; }
      .hamburger { display: block; }
      .hero-grid { flex-direction: column; }
      .hero-left, .hero-right { flex: 1 1 auto; }
      .hero h1 { font-size: 36px; }
      .stats-grid { grid-template-columns: repeat(2, 1fr); }
      .card-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .section h2 { font-size: 28px; }
    }

    @media (max-width: 640px) {
      .hero h1 { font-size: 32px; }
      .section h2 { font-size: 26px; }
      .feature-card:hover { transform: none; }
      .case-card:hover { transform: none; }
    }