/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5CE4;
      --primary-light: rgba(78,110,242,0.06);
      --green: #00B578;
      --orange: #FF9F0A;
      --red: #FA5151;
      --bg: #F5F6FA;
      --white: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --border: #E8EAED;
      --radius: 12px;
      --radius-sm: 8px;
      --shadow: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 4px 20px rgba(0,0,0,0.08);
      --font: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --max-width: 1200px;
      --space-section: 80px;
      --space-gutter: 24px;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }

    body {
      font-family: var(--font);
      font-size: 16px;
      line-height: 1.6;
      color: var(--text);
      background-color: var(--bg);
      min-height: 100vh;
      transition: background-color 0.2s;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

    /* 容器 */
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding-left: var(--space-gutter);
      padding-right: var(--space-gutter);
    }

    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 40;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border);
      height: 64px;
      display: flex;
      align-items: center;
      transition: background 0.3s;
    }

    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text);
      transition: color 0.2s;
    }

    .nav-links a:hover {
      color: var(--primary);
    }

    .btn-primary-sm {
      background: var(--primary);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 14px;
      box-shadow: 0 4px 12px rgba(78,110,242,0.3);
      transition: all 0.2s ease;
      border: none;
      cursor: pointer;
    }

    .btn-primary-sm:hover {
      background: var(--primary-hover);
      box-shadow: 0 6px 18px rgba(78,110,242,0.4);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text);
      cursor: pointer;
    }

    /* Hero */
    .hero {
      padding: 60px 0 80px;
    }

    .hero-card {
      background: var(--white);
      border-radius: 16px;
      padding: 48px 48px;
      box-shadow: var(--shadow);
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
    }

    .hero-content {
      flex: 1 1 55%;
    }

    .hero-image {
      flex: 0 0 40%;
    }

    .hero-image img {
      border-radius: var(--radius);
      box-shadow: 0 8px 24px rgba(0,0,0,0.06);
    }

    .hero h1 {
      font-size: 36px;
      line-height: 1.4;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text);
    }

    .hero .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
    }

    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      box-shadow: 0 0 16px rgba(78,110,242,0.35);
      border: none;
      transition: all 0.2s ease;
      cursor: pointer;
      display: inline-block;
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 0 24px rgba(78,110,242,0.55);
    }

    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 1.5px solid var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      transition: background 0.2s;
      cursor: pointer;
      display: inline-block;
    }

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

    .floating-badges {
      display: flex;
      gap: 16px;
      margin-top: 24px;
      flex-wrap: wrap;
    }

    .badge-glass {
      background: rgba(255,255,255,0.7);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(255,255,255,0.6);
      border-radius: 20px;
      padding: 8px 18px;
      font-size: 12px;
      font-weight: 500;
      color: var(--text);
      box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    }

    /* 区块标题 */
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-title h2 {
      font-size: 28px;
      font-weight: 600;
      color: var(--text);
      margin-bottom: 12px;
    }

    .section-title p {
      font-size: 16px;
      color: var(--text-secondary);
      max-width: 600px;
      margin: 0 auto;
    }

    /* 核心优势 */
    .features {
      padding: var(--space-section) 0;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .feature-card {
      background: var(--white);
      border-radius: var(--radius);
      padding: 32px 24px;
      box-shadow: var(--shadow);
      transition: transform 0.3s, box-shadow 0.3s;
      text-align: left;
    }

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

    .feature-icon {
      width: 56px;
      height: 56px;
      background: #EBF0FF;
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 28px;
    }

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

    .feature-card p {
      font-size: 16px;
      color: var(--text-secondary);
    }

    /* 使用场景 */
    .scenarios {
      padding: var(--space-section) 0;
      background: var(--white);
    }

    .grid-2x2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .scenario-card {
      background: var(--white);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow);
      transition: transform 0.2s;
    }

    .scenario-card:hover {
      transform: translateY(-4px);
    }

    .scenario-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      position: relative;
    }

    .scenario-img::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      height: 60%;
      background: linear-gradient(to top, rgba(0,0,0,0.5), transparent);
    }

    .scenario-text {
      padding: 24px;
    }

    .scenario-text h3 {
      font-size: 20px;
      margin-bottom: 6px;
    }

    .scenario-text p {
      color: var(--text-secondary);
      font-size: 14px;
    }

    /* 案例 */
    .cases {
      padding: var(--space-section) 0;
    }

    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .case-card {
      background: var(--white);
      border-radius: var(--radius);
      padding: 32px;
      display: flex;
      gap: 24px;
      align-items: center;
      box-shadow: var(--shadow);
    }

    .case-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1;
    }

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

    .case-info p {
      color: var(--text-secondary);
      margin-top: 6px;
    }

    /* 价格 */
    .pricing {
      padding: var(--space-section) 0;
      background: var(--white);
    }

    .price-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      align-items: stretch;
    }

    .price-card {
      background: var(--white);
      border-radius: var(--radius);
      padding: 32px 24px;
      box-shadow: var(--shadow);
      display: flex;
      flex-direction: column;
      border: 2px solid transparent;
    }

    .price-card.recommended {
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      border-color: var(--primary);
      box-shadow: var(--shadow-hover);
      position: relative;
    }

    .badge-recommend {
      background: var(--orange);
      color: white;
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 20px;
      font-weight: 600;
      display: inline-block;
      margin-bottom: 12px;
      align-self: flex-start;
    }

    .price {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
    }

    .price span {
      font-size: 16px;
      font-weight: 400;
      color: var(--text-secondary);
    }

    .feature-list {
      list-style: none;
      margin: 24px 0;
    }

    .feature-list li {
      margin-bottom: 12px;
      font-size: 14px;
      color: var(--text-secondary);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .fa-check {
      color: var(--green);
    }

    .fa-times {
      color: var(--border);
    }

    .btn-outline {
      margin-top: auto;
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 12px 24px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      cursor: pointer;
      transition: background 0.2s;
    }

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

    /* FAQ */
    .faq {
      padding: var(--space-section) 0;
    }

    .faq-card {
      background: var(--white);
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow);
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      color: var(--text);
      transition: color 0.2s;
    }

    .faq-question.active {
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      font-size: 16px;
      margin-top: 0;
    }

    .faq-answer.open {
      max-height: 200px;
      margin-top: 12px;
    }

    .indicator {
      font-size: 20px;
      color: var(--primary);
    }

    /* CTA 横幅 */
    .cta-banner {
      padding: var(--space-section) 0;
    }

    .cta-card {
      background: var(--white);
      border-radius: 16px;
      padding: 48px;
      text-align: center;
      box-shadow: var(--shadow);
    }

    .cta-card h2 {
      font-size: 28px;
      margin-bottom: 12px;
    }

    .subscribe {
      display: flex;
      gap: 12px;
      justify-content: center;
      margin-top: 24px;
      flex-wrap: wrap;
    }

    .input-capsule {
      padding: 14px 24px;
      border-radius: 24px;
      border: 1px solid var(--border);
      background: white;
      width: 260px;
      outline: none;
      transition: border 0.2s, box-shadow 0.2s;
    }

    .input-capsule:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(78,110,242,0.15);
    }

    /* 页脚 */
    .footer {
      background: #1F2329;
      color: var(--text-secondary);
      padding: 48px 0 24px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    .footer-logo {
      font-size: 20px;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }

    .footer a {
      color: var(--text-secondary);
      font-size: 14px;
      display: block;
      margin-bottom: 8px;
    }

    .footer a:hover {
      color: white;
    }

    .copyright {
      text-align: center;
      font-size: 12px;
      margin-top: 32px;
      color: var(--text-secondary);
      border-top: 1px solid #2E3239;
      padding-top: 16px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .grid-3, .price-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .case-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 768px) {
      :root {
        --space-section: 48px;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        box-shadow: 0 8px 20px rgba(0,0,0,0.1);
      }
      .nav-links.active {
        display: flex;
      }
      .menu-toggle {
        display: block;
      }
      .hero-card {
        flex-direction: column;
        padding: 32px;
      }
      .hero-image {
        order: -1;
      }
      .grid-2x2, .grid-3, .price-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }