*
  {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  }

  body
  {
      background: #ffffff;
      color: #000000;
      line-height: 1.6;
      min-height: 100vh;
      padding: 20px;
  }

  .container
  {
      max-width: 1200px;
      margin: 0 auto;
  }

  header
  {
      text-align: center;
      padding: 20px 10px;
      margin-bottom: 12px;
  }

  h1
  {
      font-size: 2.8rem;
      color: #000000;
      margin-bottom: 15px;
      font-weight: 700;
      letter-spacing: 3.5px;

      a
      {
          font-family: serif;
      }
  }

  .header-link
  {
      text-decoration: none;
      color: inherit;
      transition: color 0.3s ease;
  }

  .header-link:hover
  {
      color: #666666;
  }

  /* Navigation Grid - Single Column Always */
  .nav-grid
  {
      display: flex;
      flex-direction: column;
      gap: 15px;
      margin-bottom: 40px;
  }

  .nav-card
  {
      background: #f8f8f8;
      border-radius: 8px;
      overflow: hidden;
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
      transition: all 0.3s ease;
      cursor: pointer;
      padding: 25px;
      width: 100%;
  }

  .nav-card:hover
  {
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  }

  .card-content
  {
      display: flex;
      flex-direction: column;
  }

  .card-title
  {
      font-size: 1.4rem;
      margin-bottom: 0;
      color: #000000;
      position: relative;
      cursor: pointer;
      user-select: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
  }

  .card-title::after
  {
      content: '+';
      font-size: 1.6rem;
      color: #000000;
      transition: transform 0.3s ease;
  }

  .card-title.active::after
  {
      content: '-';
  }

  .card-links
  {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
      gap: 10px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, margin-top 0.3s ease;
  }

  .card-links.active
  {
      max-height: 500px;
      margin-top: 20px;
  }

  .card-links a
  {
      text-decoration: none;
      padding: 12px 15px;
      transition: all 0.2s ease;
      border-radius: 4px;
      border-left: 3px solid transparent;
      font-size: 1.1rem;
      background-color: #ffffff;
      display: flex;
      align-items: center;
      color: #000000;
  }

  .card-links a:hover
  {
      background-color: #e8e8e8;
      border-left: 3px solid #000000;
      transform: translateX(5px);
  }

  /* Category Sections */
  .category
  {
      margin-bottom: 50px;
  }

  .category-title
  {
      font-size: 1.8rem;
      color: #000000;
      margin-bottom: 20px;
  }

  /* Footer */
  footer
  {
      text-align: center;
      padding: 30px 0;
      color: #666666;
      font-size: 0.9rem;
      margin-top: 40px;
  }

  .footer-icons
  {
      display: flex;
      justify-content: center;
      gap: 35px;
      margin-bottom: 20px;
  }

  .footer-icon
  {
      font-size: 1.8rem;
      color: #000000;
      transition: all 0.3s ease;
  }

  .footer-icon:hover
  {
      color: #666666;
      transform: translateY(-3px);
  }

  .footer-text
  {
      margin-top: 15px;
      font-size: 1rem;
      color: #666666;
  }

  /* Responsive Design - Link Wrapping */
  @media (min-width: 351px) and (max-width: 700px)
  {
      .card-links
      {
          grid-template-columns: repeat(2, 1fr);
      }
  }

  @media (min-width: 701px) and (max-width: 850px)
  {
      .card-links
      {
          grid-template-columns: repeat(3, 1fr);
      }
  }

  @media (min-width: 851px)
  {
      .card-links
      {
          grid-template-columns: repeat(4, 1fr);
      }
  }

  @media (max-width: 350px)
  {
      .card-links
      {
          grid-template-columns: 1fr;
      }
  }

  @media (max-width: 768px)
  {
      h1
      {
          font-size: 2.2rem;
      }

      .category-title
      {
          font-size: 1.5rem;
      }

      .nav-card
      {
          padding: 20px;
      }

      .footer-icons
      {
          gap: 20px;
      }

      .footer-icon
      {
          font-size: 1.6rem;
      }
  }

  @media (max-width: 480px)
  {
      h1
      {
          font-size: 1.8rem;
      }

      .category-title
      {
          font-size: 1.4rem;
      }

      .card-title
      {
          font-size: 1.3rem;
      }

      .nav-card
      {
          padding: 18px;
      }

      .card-links a
      {
          font-size: 1rem;
          padding: 10px 12px;
      }

      .footer-icons
      {
          gap: 15px;
      }

      .footer-icon
      {
          font-size: 1.4rem;
      }

      .footer-text
      {
          font-size: 0.9rem;
      }
  }