/* roulang page: index */
:root {
      --primary: #1E2A3A;
      --accent: #C8A96E;
      --accent-hover: #B8995A;
      --bg: #F7F5F2;
      --card-bg: #FFFFFF;
      --text-main: #1E2A3A;
      --text-secondary: #5A6272;
      --text-muted: #8B919E;
      --border-light: #E5E0D8;
      --shadow-sm: 0 2px 12px rgba(30, 42, 58, 0.06);
      --shadow-md: 0 8px 24px rgba(30, 42, 58, 0.10);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-img: 12px;
      --transition: 0.25s ease;
      --nav-height: 72px;
      --container-max: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      scroll-padding-top: var(--nav-height);
    }
    body {
      font-family: 'Inter', PingFang SC, Microsoft YaHei, Hiragino Sans GB, sans-serif;
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(4px);
      z-index: 1000;
      height: var(--nav-height);
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow var(--transition), border-color var(--transition);
    }
    .navbar.scrolled {
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      display: flex;
      flex-direction: column;
      line-height: 1.2;
    }
    .logo-main {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
    }
    .logo-sub {
      font-size: 0.7rem;
      color: var(--text-muted);
      letter-spacing: 0.3px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 0.25rem 0;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent);
      transform: scaleX(0);
      transition: transform var(--transition);
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      transform: scaleX(1);
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      cursor: pointer;
      transition: background var(--transition), transform 0.15s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-1px);
    }
    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--accent);
      color: var(--accent);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      cursor: pointer;
      transition: background var(--transition), color var(--transition);
      display: inline-block;
      text-align: center;
    }
    .btn-secondary:hover {
      background: rgba(200,169,110,0.08);
    }
    .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: all 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: white;
      z-index: 999;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 2rem;
      transform: translateY(-100%);
      transition: transform 0.35s ease;
    }
    .mobile-menu.open {
      transform: translateY(0);
    }
    .mobile-menu a {
      font-size: 1.3rem;
      font-weight: 500;
      color: var(--primary);
    }
    /* 区块间距 */
    section {
      padding: 80px 0;
    }
    /* Hero */
    .hero {
      padding-top: calc(var(--nav-height) + 40px);
      background-color: var(--bg);
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-content {
      flex: 1;
    }
    .hero h1 {
      font-size: 2.5rem;
      font-weight: 700;
      line-height: 1.3;
      color: var(--primary);
      margin-bottom: 1.2rem;
      letter-spacing: -0.5px;
    }
    .hero-sub {
      font-size: 1rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
      max-width: 450px;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      margin-bottom: 2.5rem;
      flex-wrap: wrap;
    }
    .hero-stats {
      display: flex;
      gap: 2rem;
      flex-wrap: wrap;
    }
    .stat-item {
      display: flex;
      flex-direction: column;
    }
    .stat-number {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--accent);
      font-family: 'Inter', sans-serif;
    }
    .stat-label {
      font-size: 0.8rem;
      color: var(--text-muted);
    }
    .hero-image {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-md);
      background: var(--border-light);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .decor-line {
      position: absolute;
      right: 0;
      bottom: 0;
      width: 180px;
      height: 180px;
      border-right: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
      opacity: 0.4;
    }
    /* 板块标题 */
    .section-title {
      font-size: 2rem;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 1rem;
      text-align: center;
    }
    .section-desc {
      font-size: 1rem;
      color: var(--text-secondary);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 3rem;
    }
    /* 优势卡片 */
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .card-advantage {
      background: var(--card-bg);
      padding: 32px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform var(--transition), box-shadow var(--transition);
      text-align: center;
    }
    .card-advantage:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .adv-icon {
      font-size: 2.4rem;
      color: var(--accent);
      margin-bottom: 1.2rem;
    }
    .card-advantage h3 {
      font-size: 1.2rem;
      font-weight: 600;
      margin-bottom: 0.8rem;
    }
    .card-advantage p {
      color: var(--text-secondary);
      font-size: 0.9rem;
    }
    /* 场景交替 */
    .scene-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 80px;
    }
    .scene-row.reverse {
      flex-direction: row-reverse;
    }
    .scene-img {
      flex: 1;
      border-radius: var(--radius-img);
      overflow: hidden;
      background: #e0dbd2;
    }
    .scene-img img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .scene-text {
      flex: 1;
    }
    .scene-text h2 {
      font-size: 1.8rem;
      font-weight: 600;
      margin-bottom: 1rem;
    }
    .scene-text p {
      color: var(--text-secondary);
      margin-bottom: 1.5rem;
    }
    .link-more {
      color: var(--accent);
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: gap 0.2s;
    }
    .link-more:hover {
      gap: 8px;
    }
    /* 案例卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card-case {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: transform var(--transition), box-shadow var(--transition);
    }
    .card-case:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .case-img {
      height: 200px;
      background: #d9d3ca;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-body {
      padding: 24px;
    }
    .case-tag {
      background: #f0ede7;
      color: var(--text-secondary);
      font-size: 0.7rem;
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 0.8rem;
    }
    .case-body h3 {
      font-size: 1.2rem;
      margin-bottom: 0.8rem;
    }
    .case-result {
      font-size: 1.8rem;
      font-weight: 700;
      color: #0D5C4A;
      font-family: 'Inter', sans-serif;
    }
    .case-quote {
      font-style: italic;
      color: var(--text-muted);
      margin-top: 0.6rem;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
    }
    .faq-question {
      display: flex;
      align-items: center;
      justify-content: space-between;
      cursor: pointer;
      font-weight: 600;
      font-size: 1rem;
      position: relative;
      padding-left: 12px;
    }
    .faq-question::before {
      content: '';
      position: absolute;
      left: 0;
      top: 4px;
      bottom: 4px;
      width: 3px;
      background: var(--accent);
      border-radius: 2px;
    }
    .faq-toggle {
      font-size: 1.3rem;
      color: var(--accent);
      transition: transform 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 0.9rem;
      padding-left: 12px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-item.active .faq-toggle {
      transform: rotate(45deg);
    }
    /* CTA */
    .cta-band {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 80px 24px;
    }
    .cta-band h2 {
      font-size: 2rem;
      font-weight: 600;
      margin-bottom: 1rem;
    }
    .cta-sub {
      color: #cfd3da;
      margin-bottom: 2rem;
    }
    .cta-buttons {
      display: flex;
      gap: 1rem;
      justify-content: center;
      flex-wrap: wrap;
    }
    .btn-white {
      border: 1.5px solid white;
      color: white;
      background: transparent;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background 0.2s;
    }
    .btn-white:hover {
      background: rgba(255,255,255,0.1);
    }
    /* 页脚 */
    .footer {
      background: #EDEBE6;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    .footer h4 {
      font-weight: 600;
      margin-bottom: 1rem;
    }
    .footer p, .footer a {
      color: var(--text-secondary);
      font-size: 0.9rem;
      line-height: 1.8;
    }
    .footer a:hover {
      color: var(--accent);
    }
    .social-icons {
      display: flex;
      gap: 12px;
      margin-top: 1rem;
    }
    .social-icons span {
      width: 32px;
      height: 32px;
      background: #ccc;
      border-radius: 50%;
      display: inline-block;
    }
    .copyright {
      border-top: 1px solid #d9d5cd;
      margin-top: 2.5rem;
      padding-top: 1.5rem;
      display: flex;
      justify-content: space-between;
      font-size: 0.8rem;
      color: var(--text-muted);
    }
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .hero .container { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu { display: flex; }
      .grid-4, .grid-3 { grid-template-columns: 1fr; }
      .scene-row, .scene-row.reverse { flex-direction: column; }
      section { padding: 60px 0; }
      .hero h1 { font-size: 1.8rem; }
      .footer-grid { grid-template-columns: 1fr; }
    }
    .img-placeholder {
      background-color: #E5E0D8;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-muted);
    }