:root {
      --primary-color: #007bff; /* Xanh dương */
      --secondary-color: #6c757d; /* Xám */
      --accent-color: #ffc107; /* Vàng */
      --text-color: #333; /* Đen */
      --background-color: #f8f9fa; /* Trắng xám nhạt */
      --dark-background: #212529; /* Đen đậm */
      --light-text: #ffffff; /* Trắng */
      --border-radius: 8px;
      --spacing-unit: 1rem;
    }

    .page-tai-c54 {
      font-family: 'Arial', sans-serif;
      line-height: 1.6;
      color: var(--text-color);
      background-color: var(--background-color);
      padding-bottom: 80px; /* Để chừa chỗ cho nút tải nổi */
    }

    .page-tai-c54__container {
      max-width: 1200px;
      margin: 0 auto;
      padding: var(--spacing-unit);
    }

    .page-tai-c54__section {
      background-color: var(--light-text);
      border-radius: var(--border-radius);
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
      margin-bottom: calc(var(--spacing-unit) * 2);
      padding: calc(var(--spacing-unit) * 2);
      text-align: center;
    }

    .page-tai-c54__hero-section {
      background-color: var(--dark-background);
      color: var(--light-text);
      padding: 10px var(--spacing-unit) calc(var(--spacing-unit) * 3); /* 10px padding-top for header offset */
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    .page-tai-c54__hero-background {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      object-fit: cover;
      opacity: 0.3;
      z-index: 0;
    }

    .page-tai-c54__hero-content {
      position: relative;
      z-index: 1;
      max-width: 900px;
      margin: 0 auto;
    }

    .page-tai-c54__hero-content h1 {
      font-size: 2.8rem;
      margin-bottom: var(--spacing-unit);
      color: var(--accent-color);
      line-height: 1.2;
    }

    .page-tai-c54__hero-content p {
      font-size: 1.2rem;
      margin-bottom: calc(var(--spacing-unit) * 2);
    }

    .page-tai-c54__download-buttons {
      display: flex;
      justify-content: center;
      gap: var(--spacing-unit);
      margin-top: calc(var(--spacing-unit) * 2);
    }

    .page-tai-c54__download-button {
      display: inline-block;
      background-color: var(--primary-color);
      color: var(--light-text);
      padding: 0.8rem 2rem;
      border-radius: 50px;
      text-decoration: none;
      font-weight: bold;
      font-size: 1.1rem;
      transition: background-color 0.3s ease, transform 0.2s ease;
      border: none;
      cursor: pointer;
    }

    .page-tai-c54__download-button:hover {
      background-color: #0056b3;
      transform: translateY(-2px);
    }

    .page-tai-c54__download-button--accent {
      background-color: var(--accent-color);
      color: var(--dark-background);
    }

    .page-tai-c54__download-button--accent:hover {
      background-color: #e0a800;
    }

    .page-tai-c54__image {
      max-width: 100%;
      height: auto;
      border-radius: var(--border-radius);
      margin-top: calc(var(--spacing-unit) * 2);
      box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
      display: block;
      margin-left: auto;
      margin-right: auto;
      min-width: 200px; /* Minimum size requirement */
      min-height: 200px; /* Minimum size requirement */
      object-fit: cover;
    }

    .page-tai-c54__section h2 {
      color: var(--primary-color);
      font-size: 2rem;
      margin-bottom: calc(var(--spacing-unit) * 1.5);
      text-align: center;
    }

    .page-tai-c54__section h3 {
      color: var(--text-color);
      font-size: 1.5rem;
      margin-top: var(--spacing-unit);
      margin-bottom: calc(var(--spacing-unit) * 0.5);
    }

    .page-tai-c54__benefits-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: calc(var(--spacing-unit) * 2);
      margin-top: calc(var(--spacing-unit) * 2);
      text-align: left;
    }

    .page-tai-c54__benefit-item {
      background-color: var(--background-color);
      padding: var(--spacing-unit);
      border-radius: var(--border-radius);
      box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
      text-align: center;
      display: flex;
      flex-direction: column;
      align-items: center;
      box-sizing: border-box;
    }

    .page-tai-c54__benefit-item img {
      max-width: 100%;
      height: auto;
      margin-bottom: var(--spacing-unit);
      border-radius: var(--border-radius);
      min-width: 200px;
      min-height: 200px;
      object-fit: cover;
    }

    .page-tai-c54__steps-list {
      list-style: none;
      padding: 0;
      text-align: left;
    }

    .page-tai-c54__steps-list li {
      background-color: var(--background-color);
      margin-bottom: var(--spacing-unit);
      padding: var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
      border-left: 5px solid var(--primary-color);
      border-radius: var(--border-radius);
      box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
      display: flex;
      align-items: flex-start;
      gap: var(--spacing-unit);
      box-sizing: border-box;
      word-wrap: break-word; /* Ensure text wraps */
      overflow-wrap: break-word;
    }

    .page-tai-c54__steps-list li strong {
      color: var(--primary-color);
      font-size: 1.2em;
      flex-shrink: 0;
      width: 30px;
      text-align: center;
    }

    .page-tai-c54__game-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: calc(var(--spacing-unit) * 1.5);
      margin-top: calc(var(--spacing-unit) * 2);
    }

    .page-tai-c54__game-card {
      background-color: var(--background-color);
      border-radius: var(--border-radius);
      box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
      overflow: hidden;
      text-align: center;
      transition: transform 0.2s ease;
      box-sizing: border-box;
    }

    .page-tai-c54__game-card:hover {
      transform: translateY(-5px);
    }

    .page-tai-c54__game-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      min-width: 200px;
      min-height: 200px;
    }

    .page-tai-c54__game-card h3 {
      margin: var(--spacing-unit) 0;
      color: var(--primary-color);
      font-size: 1.3rem;
    }

    .page-tai-c54__game-card p {
      padding: 0 var(--spacing-unit) var(--spacing-unit);
      font-size: 0.95rem;
    }

    .page-tai-c54__promotion-banner {
      background-color: var(--primary-color);
      color: var(--light-text);
      padding: calc(var(--spacing-unit) * 2);
      border-radius: var(--border-radius);
      margin-top: calc(var(--spacing-unit) * 2);
    }

    .page-tai-c54__promotion-banner h2 {
      color: var(--accent-color);
      margin-bottom: var(--spacing-unit);
    }

    .page-tai-c54__promotion-banner p {
      font-size: 1.1rem;
      margin-bottom: var(--spacing-unit);
    }

    .page-tai-c54__faq-section {
      text-align: left;
    }

    .page-tai-c54__faq-item {
      background-color: var(--light-text);
      border: 1px solid #ddd;
      border-radius: var(--border-radius);
      margin-bottom: var(--spacing-unit);
      overflow: hidden;
    }

    .page-tai-c54__faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: var(--spacing-unit) calc(var(--spacing-unit) * 1.5);
      background-color: #f1f1f1;
      cursor: pointer;
      font-weight: bold;
      color: var(--text-color);
      transition: background-color 0.3s ease;
      user-select: none;
    }

    .page-tai-c54__faq-question:hover {
      background-color: #e9e9e9;
    }

    .page-tai-c54__faq-question h3 {
      margin: 0;
      font-size: 1.1rem;
      color: var(--primary-color);
      pointer-events: none; /* Prevent h3 from blocking click event */
    }

    .page-tai-c54__faq-toggle {
      font-size: 1.5rem;
      line-height: 1;
      transition: transform 0.3s ease;
      pointer-events: none; /* Prevent toggle icon from blocking click event */
    }

    .page-tai-c54__faq-answer {
      max-height: 0;
      overflow: hidden;
      padding: 0 15px; /* Initial padding to match question padding */
      transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), padding 0.4s ease, opacity 0.4s ease;
      opacity: 0;
      color: var(--text-color);
    }

    .page-tai-c54__faq-item.active .page-tai-c54__faq-answer {
      max-height: 2000px !important; /* Sufficiently large to contain content */
      padding: 20px 15px !important; /* Adjusted padding when active */
      opacity: 1;
    }

    .page-tai-c54__faq-item.active .page-tai-c54__faq-toggle {
      transform: rotate(45deg); /* Change '+' to 'x' visually */
    }

    .page-tai-c54__sticky-cta {
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background-color: var(--primary-color);
      padding: 15px 0;
      text-align: center;
      box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
      z-index: 1000;
    }

    .page-tai-c54__sticky-cta .page-tai-c54__download-button {
      background-color: var(--accent-color);
      color: var(--dark-background);
      font-size: 1.2rem;
      padding: 0.9rem 2.5rem;
    }

    .page-tai-c54__sticky-cta .page-tai-c54__download-button:hover {
      background-color: #e0a800;
    }

    /* Responsive Design */
    @media (max-width: 768px) {
      .page-tai-c54__hero-content h1 {
        font-size: 2rem;
      }

      .page-tai-c54__hero-content p {
        font-size: 1rem;
      }

      .page-tai-c54__download-buttons {
        flex-direction: column;
        gap: 0.8rem;
      }

      .page-tai-c54__download-button {
        width: 80%;
        margin: 0 auto;
        padding: 0.7rem 1.5rem;
      }

      .page-tai-c54__section {
        padding: var(--spacing-unit);
      }

      .page-tai-c54__section h2 {
        font-size: 1.6rem;
      }

      .page-tai-c54__section h3 {
        font-size: 1.3rem;
      }

      .page-tai-c54__benefits-grid,
      .page-tai-c54__game-grid {
        grid-template-columns: 1fr;
      }

      .page-tai-c54__benefit-item,
      .page-tai-c54__game-card {
        width: 100% !important;
        max-width: 100% !important;
        box-sizing: border-box !important;
        margin-left: 0 !important;
        margin-right: 0 !important;
      }

      .page-tai-c54__steps-list {
        width: 100% !important;
        max-width: 100% !important;
        padding: 0 !important;
        margin-left: 0 !important;
        margin-right: 0 !important;
        box-sizing: border-box !important;
      }

      .page-tai-c54__steps-list li {
        width: 100% !important;
        max-width: 100% !important;
        box-sizing: border-box !important;
        padding: 10px 15px !important;
        margin-left: 0 !important;
        margin-right: 0 !important;
        word-wrap: break-word !important;
        overflow-wrap: break-word !important;
      }

      .page-tai-c54__image {
        max-width: 100% !important;
        height: auto !important;
        box-sizing: border-box !important;
        min-width: 200px !important;
        min-height: 200px !important;
      }

      .page-tai-c54__faq-question h3 {
        font-size: 1rem;
      }

      .page-tai-c54__faq-answer {
        padding: 0 10px;
      }

      .page-tai-c54__faq-item.active .page-tai-c54__faq-answer {
        padding: 15px 10px !important;
      }

      .page-tai-c54__sticky-cta {
        padding: 10px 0;
      }

      .page-tai-c54__sticky-cta .page-tai-c54__download-button {
        font-size: 1rem;
        padding: 0.8rem 2rem;
      }
    }