:root {
      --page-66f-primary-color: #007bff; /* Xanh dương */
      --page-66f-secondary-color: #ffc107; /* Vàng */
      --page-66f-dark-background: #1a1a1a;
      --page-66f-light-text: #f0f0f0;
      --page-66f-gray-text: #cccccc;
      --page-66f-border-color: #333333;
      --page-66f-button-bg: #28a745; /* Xanh lá cây */
      --page-66f-button-hover-bg: #218838;
      --page-66f-red-color: #dc3545; /* Đỏ */
    }

    .page-66f {
      font-family: 'Arial', sans-serif;
      color: var(--page-66f-light-text);
      background-color: var(--page-66f-dark-background);
      line-height: 1.6;
      padding-top: 10px; /* Adjust as per fixed nav bar offset */
    }

    .page-66f__section {
      padding: 40px 20px;
      max-width: 1200px;
      margin: 0 auto;
      text-align: center;
    }

    .page-66f__section--dark {
      background-color: #0d0d0d;
    }

    .page-66f__section-title {
      color: var(--page-66f-secondary-color);
      font-size: 2.5em;
      margin-bottom: 25px;
      text-transform: uppercase;
      font-weight: bold;
    }

    .page-66f__section-subtitle {
      color: var(--page-66f-gray-text);
      font-size: 1.2em;
      margin-bottom: 40px;
    }

    /* Hero Section */
    .page-66f__hero-section {
      position: relative;
      overflow: hidden;
      padding: 10px 0 60px 0; /* Adjusted padding-top */
      min-height: 500px;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-direction: column;
      text-align: center;
      background-color: var(--page-66f-dark-background);
    }

    .page-66f__hero-image {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      object-fit: cover;
      z-index: 1;
      opacity: 0.3;
    }

    .page-66f__hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      padding: 20px;
      background-color: rgba(0, 0, 0, 0.6);
      border-radius: 10px;
    }

    .page-66f__hero-title {
      font-size: 3em;
      color: var(--page-66f-secondary-color);
      margin-bottom: 20px;
      line-height: 1.2;
    }

    .page-66f__hero-description {
      font-size: 1.2em;
      color: var(--page-66f-light-text);
      margin-bottom: 30px;
    }

    /* Floating Buttons */
    .page-66f__floating-buttons {
      position: fixed;
      bottom: 20px;
      left: 50%;
      transform: translateX(-50%);
      display: flex;
      gap: 15px;
      z-index: 1000;
      width: calc(100% - 40px);
      max-width: 400px;
      justify-content: center;
    }

    .page-66f__button {
      background-color: var(--page-66f-button-bg);
      color: var(--page-66f-light-text);
      border: none;
      padding: 12px 25px;
      border-radius: 30px;
      font-size: 1.1em;
      font-weight: bold;
      cursor: pointer;
      transition: background-color 0.3s ease, transform 0.2s ease;
      flex-grow: 1;
      text-align: center;
      text-decoration: none; /* Ensure no underline for external link */
    }

    .page-66f__button:hover {
      background-color: var(--page-66f-button-hover-bg);
      transform: translateY(-2px);
    }

    .page-66f__button--secondary {
      background-color: var(--page-66f-primary-color);
    }

    .page-66f__button--secondary:hover {
      background-color: #0056b3;
    }

    /* Product Display */
    .page-66f__product-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 30px;
      margin-top: 40px;
    }

    .page-66f__product-item {
      background-color: #2a2a2a;
      border-radius: 10px;
      overflow: hidden;
      box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding-bottom: 20px;
      box-sizing: border-box; /* Important for responsive lists */
    }

    .page-66f__product-item:hover {
      transform: translateY(-5px);
      box-shadow: 0 8px 20px rgba(0, 0, 0, 0.5);
    }

    .page-66f__product-image-wrapper {
      width: 100%;
      height: 200px;
      overflow: hidden;
      margin-bottom: 15px;
    }

    .page-66f__product-image {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    .page-66f__product-title {
      font-size: 1.5em;
      color: var(--page-66f-secondary-color);
      margin-bottom: 10px;
      padding: 0 15px;
    }

    .page-66f__product-description {
      font-size: 0.95em;
      color: var(--page-66f-gray-text);
      padding: 0 15px;
    }

    /* Promotions Section */
    .page-66f__promotions-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 25px;
      margin-top: 40px;
    }

    .page-66f__promotion-card {
      background-color: #2a2a2a;
      border-radius: 10px;
      padding: 25px;
      text-align: left;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
      border-left: 5px solid var(--page-66f-primary-color);
      box-sizing: border-box; /* Important for responsive lists */
    }

    .page-66f__promotion-card h3 {
      color: var(--page-66f-secondary-color);
      font-size: 1.4em;
      margin-bottom: 10px;
    }

    .page-66f__promotion-card p {
      color: var(--page-66f-gray-text);
      font-size: 0.95em;
      margin-bottom: 15px;
    }

    .page-66f__promotion-cta {
      display: inline-block;
      background-color: var(--page-66f-button-bg);
      color: var(--page-66f-light-text);
      padding: 10px 20px;
      border-radius: 25px;
      text-decoration: none;
      font-weight: bold;
      transition: background-color 0.3s ease;
    }

    .page-66f__promotion-cta:hover {
      background-color: var(--page-66f-button-hover-bg);
    }

    /* Why Choose Us Section */
    .page-66f__feature-list {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: 25px;
      margin-top: 40px;
      list-style: none;
      padding: 0;
    }

    .page-66f__feature-item {
      background-color: #2a2a2a;
      border-radius: 10px;
      padding: 25px;
      text-align: left;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
      border-top: 5px solid var(--page-66f-secondary-color);
      box-sizing: border-box; /* Important for responsive lists */
    }

    .page-66f__feature-item h3 {
      color: var(--page-66f-primary-color);
      font-size: 1.3em;
      margin-bottom: 10px;
    }

    .page-66f__feature-item p {
      color: var(--page-66f-gray-text);
      font-size: 0.9em;
    }

    /* Providers and Payment Methods */
    .page-66f__logo-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
      gap: 20px;
      margin-top: 40px;
      align-items: center;
      justify-items: center;
    }

    .page-66f__logo-item {
      background-color: #2a2a2a;
      padding: 15px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      height: 100px;
      box-sizing: border-box; /* Important for responsive lists */
    }

    .page-66f__logo-item img {
      max-width: 100%;
      max-height: 70px;
      height: auto;
      object-fit: contain;
      display: block;
    }

    /* FAQ Section */
    .page-66f__faq-container {
      margin-top: 40px;
      text-align: left;
    }

    .page-66f__faq-item {
      background-color: #2a2a2a;
      border-radius: 8px;
      margin-bottom: 15px;
      overflow: hidden;
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
      box-sizing: border-box; /* Important for responsive lists */
    }

    .page-66f__faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 15px 20px;
      background-color: #333333;
      cursor: pointer;
      user-select: none;
      border-bottom: 1px solid var(--page-66f-border-color);
      transition: background-color 0.3s ease;
    }

    .page-66f__faq-question:hover {
      background-color: #444444;
    }

    .page-66f__faq-question h3 {
      margin: 0;
      font-size: 1.1em;
      color: var(--page-66f-light-text);
      pointer-events: none; /* Prevent h3 from blocking click event */
    }

    .page-66f__faq-toggle {
      font-size: 1.5em;
      font-weight: bold;
      color: var(--page-66f-secondary-color);
      transition: transform 0.3s ease;
      pointer-events: none; /* Prevent toggle from blocking click event */
    }

    .page-66f__faq-answer {
      max-height: 0;
      overflow: hidden;
      padding: 0 20px;
      color: var(--page-66f-gray-text);
      transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), padding 0.4s ease, opacity 0.4s ease;
      opacity: 0;
    }

    .page-66f__faq-item.active .page-66f__faq-answer {
      max-height: 2000px !important; /* Sufficiently large */
      padding: 20px 20px !important;
      opacity: 1;
    }

    .page-66f__faq-item.active .page-66f__faq-toggle {
      transform: rotate(45deg); /* Plus to Minus visual effect */
    }

    /* Social Media */
    .page-66f__social-list {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 20px;
      margin-top: 40px;
      list-style: none;
      padding: 0;
    }

    .page-66f__social-item {
      background-color: #2a2a2a;
      border-radius: 8px;
      padding: 15px 25px;
      color: var(--page-66f-primary-color);
      font-weight: bold;
      font-size: 1.1em;
      transition: background-color 0.3s ease, color 0.3s ease;
      box-sizing: border-box; /* Important for responsive lists */
    }

    .page-66f__social-item:hover {
      background-color: var(--page-66f-primary-color);
      color: var(--page-66f-light-text);
    }

    /* Responsive Design */
    @media (max-width: 768px) {
      .page-66f__section {
        padding: 30px 15px;
      }

      .page-66f__section-title {
        font-size: 2em;
      }

      .page-66f__hero-title {
        font-size: 2.2em;
      }

      .page-66f__hero-description {
        font-size: 1em;
      }

      .page-66f__product-grid,
      .page-66f__promotions-grid,
      .page-66f__feature-list,
      .page-66f__logo-grid {
        grid-template-columns: 1fr;
        gap: 20px;
      }

      .page-66f__product-item,
      .page-66f__promotion-card,
      .page-66f__feature-item,
      .page-66f__logo-item,
      .page-66f__faq-item,
      .page-66f__social-item {
        width: 100% !important;
        max-width: 100% !important;
        box-sizing: border-box !important;
        margin-left: 0 !important;
        margin-right: 0 !important;
      }

      .page-66f__product-image-wrapper {
        height: 180px;
      }

      .page-66f__faq-question {
        padding: 12px 15px;
      }

      .page-66f__faq-question h3 {
        font-size: 1em;
      }

      .page-66f__faq-answer {
        padding: 0 15px;
      }

      .page-66f__faq-item.active .page-66f__faq-answer {
        padding: 15px 15px !important;
      }

      .page-66f__social-list {
        flex-direction: column;
        align-items: center;
      }

      .page-66f__floating-buttons {
        gap: 10px;
        bottom: 15px;
        max-width: calc(100% - 30px);
      }

      .page-66f__button {
        padding: 10px 20px;
        font-size: 1em;
      }

      /* Ensure images are responsive and don't overflow */
      .page-66f__product-image,
      .page-66f__logo-item img,
      .page-66f__hero-image {
        max-width: 100%;
        height: auto;
      }

      .page-66f__product-image-wrapper {
        width: 100%;
        max-width: 100%;
        overflow: hidden;
        box-sizing: border-box;
      }

      .page-66f__logo-item {
        width: 100%;
        max-width: 100%;
        overflow: hidden;
        box-sizing: border-box;
      }
    }