:root {
    --bg-color: #f1f4ff;
    --card-bg: #ffffff;
    --text-main: #182033;
    --text-muted: #4b5563;
    --accent-blue: #3b82f6;
    --border-subtle: rgba(24, 32, 51, 0.08);
  }

  body {
    background-color: var(--bg-color);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--text-main);
    line-height: 1.65;
    padding: 40px 20px;
    margin: 0;
    -webkit-font-smoothing: antialiased;
  }

  .content-container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--card-bg);
    padding: 48px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(24, 32, 51, 0.05);
    border: 1px solid var(--border-subtle);
  }

  /* Font Size 36: Product Name */
  .title-36 {
    font-size: 36px;
    font-weight: 800;
    line-height: 1.25;
    color: var(--text-main);
    margin-bottom: 24px;
    letter-spacing: -0.5px;
  }

  /* Font Size 22: Section Headings */
  .heading-22 {
    font-size: 22px;
    font-weight: 700;
    color: var(--accent-blue);
    margin-top: 36px;
    margin-bottom: 16px;
    border-bottom: 2px solid rgba(59, 130, 246, 0.15);
    padding-bottom: 8px;
    letter-spacing: -0.2px;
  }

  /* Font Size 18: Body Text */
  .body-18 {
    font-size: 18px;
    line-height: 1.75;
    color: var(--text-muted);
    margin-bottom: 20px;
  }

  /* Font Size 18: Feature List */
  .list-18 {
    font-size: 18px;
    line-height: 1.85;
    color: var(--text-muted);
    padding-left: 24px;
    margin-bottom: 24px;
  }

  .list-18 li {
    margin-bottom: 12px;
  }

  strong {
    color: var(--text-main);
    font-weight: 700;
  }

  @media (max-width: 640px) {
    .content-container {
      padding: 26px 20px;
    }
    .title-36 {
      font-size: 28px;
    }
    .heading-22 {
      font-size: 20px;
    }
    .body-18, .list-18 {
      font-size: 16px;
    }
  }