/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary: #1B5E9B;
      --primary-dark: #0D3B66;
      --accent: #F4A261;
      --accent-hover: #E07B3C;
      --bg-light: #F8F9FA;
      --card-bg: #FFFFFF;
      --text-main: #1A1A1A;
      --text-secondary: #5A5A5A;
      --text-muted: #8A8A8A;
      --border-light: #E9ECEF;
      --footer-bg: #0D3B66;
      --footer-text: #B0C4DE;
      --copyright-bg: #091D33;
      --copyright-text: #6A7F99;
      
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --radius-img: 8px;
      
      --shadow-card: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-card-hover: 0 6px 20px rgba(0,0,0,0.10);
      --transition-base: 0.25s ease;
      --transition-fast: 0.2s ease;
      
      --font-h1: 36px;
      --font-h2: 28px;
      --font-h3: 22px;
      --font-body: 16px;
      --font-small: 14px;
      
      --container-max: 1200px;
      --nav-height: 64px;
    }
    
    /* ----- 全局重置 ----- */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      font-size: var(--font-body);
      line-height: 1.8;
      color: var(--text-main);
      background-color: var(--bg-light);
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-fast);
    }
    
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      transition: all var(--transition-fast);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }
    
    /* ----- 容器与布局 ----- */
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    section {
      padding: 80px 0;
    }
    
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
      :root {
        --font-h1: 28px;
        --font-h2: 22px;
        --font-h3: 19px;
        --font-body: 15px;
      }
    }
    
    /* ----- 导航栏 ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: background var(--transition-fast);
    }
    
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary-dark);
      letter-spacing: 1px;
    }
    .logo span {
      color: var(--accent);
    }
    
    .nav-links {
      display: flex;
      gap: 32px;
      list-style: none;
    }
    
    .nav-links a {
      font-size: var(--font-small);
      color: var(--text-secondary);
      font-weight: 500;
      position: relative;
      padding: 4px 0;
    }
    
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent);
    }
    
    .btn-nav {
      background: var(--accent);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: var(--font-small);
    }
    .btn-nav:hover {
      background: var(--accent-hover);
      transform: translateY(-1px);
    }
    
    .hamburger {
      display: none;
      font-size: 24px;
      color: var(--primary-dark);
      background: none;
      border: none;
    }
    
    @media (max-width: 768px) {
      .nav-links, .btn-nav.desktop-cta {
        display: none;
      }
      .hamburger {
        display: block;
      }
    }
    
    /* 移动端抽屉菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: white;
      box-shadow: -4px 0 20px rgba(0,0,0,0.1);
      z-index: 1100;
      padding: 24px;
      display: flex;
      flex-direction: column;
      gap: 24px;
      transition: right 0.35s ease;
    }
    .mobile-menu.open {
      right: 0;
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .close-menu {
      align-self: flex-end;
      font-size: 28px;
      color: var(--text-secondary);
    }
    
    /* ----- 按钮体系 ----- */
    .btn-primary {
      background: var(--accent);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: var(--font-body);
      box-shadow: 0 2px 8px rgba(244,162,97,0.3);
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 4px 14px rgba(224,123,60,0.35);
    }
    
    .btn-secondary {
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 10px 26px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      background: transparent;
    }
    .btn-secondary:hover {
      background: var(--primary);
      color: white;
    }
    
    .btn-text {
      color: var(--primary);
      font-weight: 500;
    }
    .btn-text:hover {
      text-decoration: underline;
    }
    
    /* ----- Hero 首屏 ----- */
    .hero {
      padding-top: calc(var(--nav-height) + 60px);
      padding-bottom: 80px;
      background: var(--bg-light);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
      position: relative;
    }
    
    .hero h1 {
      font-size: 42px;
      font-weight: 700;
      color: var(--primary-dark);
      line-height: 1.3;
      margin-bottom: 20px;
    }
    .hero-subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 16px;
    }
    .hero-download-text {
      font-size: var(--font-small);
      color: var(--text-muted);
    }
    
    .hero-image-wrapper {
      background: radial-gradient(circle, rgba(27,94,155,0.08) 0%, transparent 70%);
      border-radius: 40px;
      padding: 20px;
      transform: rotate(-2deg);
      transition: transform 0.3s ease;
    }
    .hero-image-wrapper img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card-hover);
      max-height: 400px;
    }
    
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column-reverse;
        text-align: center;
      }
      .hero h1 {
        font-size: 32px;
      }
      .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
      }
      .hero-buttons {
        justify-content: center;
      }
      .hero-image-wrapper {
        transform: rotate(0);
        max-width: 280px;
        margin: 0 auto;
      }
    }
    
    /* ----- 亮点网格 ----- */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px 20px;
      text-align: center;
      box-shadow: var(--shadow-card);
      transition: all var(--transition-base);
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .feature-icon {
      font-size: 40px;
      color: var(--accent);
      margin-bottom: 20px;
      transition: transform 0.2s;
    }
    .feature-card:hover .feature-icon {
      transform: scale(1.1);
    }
    .feature-card h3 {
      font-size: var(--font-h3);
      margin-bottom: 10px;
    }
    .feature-card p {
      font-size: var(--font-small);
      color: var(--text-secondary);
    }
    
    @media (max-width: 1024px) {
      .features-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 520px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* ----- 案例瀑布流 Masonry ----- */
    .masonry-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .masonry-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all var(--transition-base);
      display: flex;
      flex-direction: column;
    }
    .masonry-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    .masonry-img {
      width: 100%;
      aspect-ratio: 4/3;
      object-fit: cover;
    }
    .masonry-content {
      padding: 20px;
    }
    .masonry-tag {
      display: inline-block;
      background: var(--border-light);
      color: var(--text-secondary);
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 8px;
    }
    .masonry-title {
      font-weight: 600;
      margin-bottom: 6px;
    }
    .masonry-stat {
      font-size: var(--font-small);
      color: var(--accent);
      font-weight: 600;
    }
    
    @media (max-width: 1024px) {
      .masonry-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 520px) {
      .masonry-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* ----- 方案对比表 ----- */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .pricing-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      text-align: center;
      position: relative;
      border: 2px solid transparent;
    }
    .pricing-card.recommended {
      border-color: var(--accent);
    }
    .badge-recommend {
      position: absolute;
      top: -12px;
      right: 20px;
      background: var(--accent);
      color: white;
      padding: 4px 16px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
    }
    .plan-name {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary-dark);
    }
    .plan-price {
      font-size: 32px;
      font-weight: 700;
      margin: 16px 0;
    }
    .plan-features {
      list-style: none;
      text-align: left;
      margin: 24px 0;
    }
    .plan-features li {
      padding: 8px 0;
      font-size: var(--font-small);
      color: var(--text-secondary);
    }
    .plan-features i {
      color: var(--accent);
      margin-right: 8px;
    }
    
    @media (max-width: 768px) {
      .pricing-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto;
      }
    }
    
    /* ----- FAQ 手风琴 ----- */
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      cursor: pointer;
      background: white;
    }
    .faq-question .q-icon {
      color: var(--accent);
      margin-right: 12px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background: #F8F9FA;
      padding: 0 24px;
    }
    .faq-answer p {
      padding: 16px 0;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
    }
    .faq-arrow {
      transition: transform 0.3s;
    }
    .faq-item.active .faq-arrow {
      transform: rotate(180deg);
    }
    
    /* ----- CTA 横幅 ----- */
    .cta-banner {
      background: var(--bg-light);
      text-align: center;
      padding: 60px 0;
    }
    .cta-banner h2 {
      color: var(--primary-dark);
    }
    .cta-banner .btn-primary {
      font-size: 18px;
      padding: 14px 40px;
      margin-top: 20px;
    }
    
    /* ----- 页脚 ----- */
    .site-footer {
      background: var(--footer-bg);
      color: var(--footer-text);
      padding: 60px 0 0;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer-brand p {
      margin: 16px 0;
      font-size: var(--font-small);
    }
    .footer-links h4 {
      color: white;
      margin-bottom: 16px;
      font-size: 16px;
    }
    .footer-links ul {
      list-style: none;
    }
    .footer-links li {
      margin-bottom: 10px;
    }
    .footer-links a:hover {
      color: var(--accent);
    }
    .footer-bottom {
      background: var(--copyright-bg);
      color: var(--copyright-text);
      text-align: center;
      padding: 20px;
      margin-top: 40px;
      font-size: 14px;
    }
    
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      color: var(--primary-dark);
    }
    .section-title p {
      color: var(--text-secondary);
      max-width: 600px;
      margin: 0 auto;
    }