/* CSS cho trang OK9 */
    :root {
        --page-ok9-primary-color: #e44d26; /* Màu chủ đạo nổi bật */
        --page-ok9-secondary-color: #f7a01d; /* Màu bổ sung */
        --page-ok9-accent-color: #4CAF50; /* Màu nhấn cho thành công/khuyến mãi */
        --page-ok9-text-color: #333;
        --page-ok9-light-text-color: #fff;
        --page-ok9-bg-light: #f9f9f9;
        --page-ok9-bg-dark: #2c3e50;
        --page-ok9-border-color: #ddd;
    }

    .page-ok9 {
        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        line-height: 1.6;
        color: var(--page-ok9-text-color);
        background-color: var(--page-ok9-bg-light);
        padding: 0;
        margin: 0;
    }

    .page-ok9__container {
        max-width: 1200px;
        margin: 0 auto;
        padding: 20px;
    }

    @media (max-width: 768px) {
        .page-ok9__container {
            padding: 10px;
        }
    }

    /* Phần Hero */
    .page-ok9__hero-section {
        position: relative;
        width: 100%;
        background-color: var(--page-ok9-bg-dark);
        color: var(--page-ok9-light-text-color);
        text-align: center;
        overflow: hidden;
        padding-top: 100px; /* Đảm bảo không bị che bởi header cố định */
        padding-bottom: 50px;
    }

    .page-ok9__hero-background {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        object-fit: cover;
        z-index: 1;
        filter: brightness(0.6); /* Làm mờ ảnh nền để dễ đọc chữ */
    }

    .page-ok9__hero-content {
        position: relative;
        z-index: 2;
        max-width: 900px;
        margin: 0 auto;
        padding: 20px;
    }

    .page-ok9__hero-title {
        font-size: 2.8em;
        margin-bottom: 15px;
        color: var(--page-ok9-light-text-color);
        text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
    }

    .page-ok9__hero-subtitle {
        font-size: 1.3em;
        margin-bottom: 30px;
        color: #e0e0e0;
    }

    .page-ok9__cta-button {
        display: inline-block;
        background-color: var(--page-ok9-primary-color);
        color: var(--page-ok9-light-text-color);
        padding: 15px 30px;
        border-radius: 8px;
        text-decoration: none;
        font-weight: bold;
        font-size: 1.1em;
        transition: background-color 0.3s ease, transform 0.2s ease;
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    }

    .page-ok9__cta-button:hover {
        background-color: #ff6a00;
        transform: translateY(-2px);
    }

    @media (max-width: 768px) {
        .page-ok9__hero-section {
            padding-top: 80px; /* Điều chỉnh cho header cố định trên di động */
            padding-bottom: 30px;
        }
        .page-ok9__hero-title {
            font-size: 2em;
        }
        .page-ok9__hero-subtitle {
            font-size: 1em;
        }
        .page-ok9__cta-button {
            padding: 12px 25px;
            font-size: 1em;
        }
    }

    /* Nút Đăng nhập nổi */
    .page-ok9__floating-button {
        position: fixed;
        bottom: 20px;
        right: 20px;
        background-color: var(--page-ok9-accent-color);
        color: var(--page-ok9-light-text-color);
        padding: 15px 25px;
        border-radius: 50px;
        text-decoration: none;
        font-weight: bold;
        font-size: 1.1em;
        box-shadow: 0 5px 20px rgba(0, 0, 0, 0.3);
        z-index: 1000;
        transition: background-color 0.3s ease, transform 0.2s ease;
        display: flex;
        align-items: center;
        justify-content: center;
        text-align: center;
        max-width: 250px; /* Giới hạn chiều rộng cho di động */
    }

    .page-ok9__floating-button:hover {
        background-color: #5cb85c;
        transform: translateY(-3px);
    }

    @media (max-width: 768px) {
        .page-ok9__floating-button {
            bottom: 15px;
            right: 15px;
            padding: 12px 20px;
            font-size: 0.95em;
            max-width: 180px;
        }
    }

    /* Kiểu dáng chung cho các phần */
    .page-ok9__section {
        padding: 60px 0;
        background-color: var(--page-ok9-bg-light);
    }

    .page-ok9__section--dark {
        background-color: var(--page-ok9-bg-dark);
        color: var(--page-ok9-light-text-color);
    }

    .page-ok9__section-title {
        font-size: 2.2em;
        color: var(--page-ok9-primary-color);
        text-align: center;
        margin-bottom: 40px;
        position: relative;
    }

    .page-ok9__section--dark .page-ok9__section-title {
        color: var(--page-ok9-secondary-color);
    }

    .page-ok9__section-title::after {
        content: '';
        display: block;
        width: 80px;
        height: 4px;
        background-color: var(--page-ok9-secondary-color);
        margin: 10px auto 0;
        border-radius: 2px;
    }

    .page-ok9__section--dark .page-ok9__section-title::after {
        background-color: var(--page-ok9-primary-color);
    }

    @media (max-width: 768px) {
        .page-ok9__section {
            padding: 40px 0;
        }
        .page-ok9__section-title {
            font-size: 1.8em;
            margin-bottom: 30px;
        }
    }

    /* Phần Giới thiệu */
    .page-ok9__intro-content {
        text-align: center;
        max-width: 800px;
        margin: 0 auto;
        font-size: 1.1em;
    }

    .page-ok9__intro-content p {
        margin-bottom: 20px;
    }

    /* Phần Danh mục trò chơi */
    .page-ok9__game-grid {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
        gap: 30px;
        padding: 20px;
    }

    .page-ok9__game-card {
        background-color: var(--page-ok9-light-text-color);
        border-radius: 12px;
        box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
        overflow: hidden;
        text-align: center;
        transition: transform 0.3s ease, box-shadow 0.3s ease;
        display: flex;
        flex-direction: column;
        height: 100%;
    }

    .page-ok9__game-card:hover {
        transform: translateY(-5px);
        box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    }

    .page-ok9__game-image {
        width: 100%;
        height: 200px; /* Chiều cao cố định để nhất quán */
        object-fit: cover;
        display: block;
        border-bottom: 1px solid var(--page-ok9-border-color);
    }

    .page-ok9__game-content {
        padding: 20px;
        flex-grow: 1;
        display: flex;
        flex-direction: column;
        justify-content: space-between;
    }

    .page-ok9__game-title {
        font-size: 1.5em;
        color: var(--page-ok9-primary-color);
        margin-bottom: 10px;
    }

    .page-ok9__game-description {
        font-size: 0.95em;
        color: #555;
        margin-bottom: 15px;
        flex-grow: 1;
    }

    @media (max-width: 768px) {
        .page-ok9__game-grid {
            grid-template-columns: 1fr;
            padding: 10px;
        }
        .page-ok9__game-image {
            height: 180px;
        }
        .page-ok9__game-title {
            font-size: 1.3em;
        }
        .page-ok9__game-description {
            font-size: 0.9em;
        }
    }

    /* Phần Hướng dẫn */
    .page-ok9__guide-steps {
        display: flex;
        flex-direction: column;
        gap: 40px;
        max-width: 900px;
        margin: 0 auto;
    }

    .page-ok9__guide-step {
        display: flex;
        align-items: center;
        gap: 30px;
        background-color: var(--page-ok9-light-text-color);
        border-radius: 12px;
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
        padding: 30px;
    }

    .page-ok9__guide-step:nth-child(even) {
        flex-direction: row-reverse;
    }

    .page-ok9__step-number {
        font-size: 2.5em;
        font-weight: bold;
        color: var(--page-ok9-secondary-color);
        min-width: 60px;
        text-align: center;
    }

    .page-ok9__step-content {
        flex: 1;
    }

    .page-ok9__step-title {
        font-size: 1.8em;
        color: var(--page-ok9-primary-color);
        margin-bottom: 10px;
    }

    .page-ok9__step-description {
        font-size: 1em;
        color: #555;
    }

    .page-ok9__step-image-wrapper {
        flex-shrink: 0;
        width: 40%;
        max-width: 350px;
        border-radius: 8px;
        overflow: hidden;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    }
    .page-ok9__step-image {
        width: 100%;
        height: auto;
        display: block;
        max-width: 100%; /* Đảm bảo responsive */
        box-sizing: border-box; /* Bao gồm padding/border trong tính toán chiều rộng */
    }

    @media (max-width: 768px) {
        .page-ok9__guide-step,
        .page-ok9__guide-step:nth-child(even) {
            flex-direction: column;
            text-align: center;
            padding: 20px;
        }
        .page-ok9__step-image-wrapper {
            width: 100%;
            max-width: 100%;
            margin-top: 20px;
        }
        .page-ok9__step-number {
            font-size: 2em;
            min-width: unset;
        }
        .page-ok9__step-title {
            font-size: 1.5em;
        }
    }

    /* Phần Khuyến mãi */
    .page-ok9__promo-list {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
        gap: 25px;
        padding: 20px;
    }

    .page-ok9__promo-item {
        background-color: var(--page-ok9-light-text-color);
        border-radius: 12px;
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
        padding: 25px;
        text-align: left;
        transition: transform 0.3s ease, box-shadow 0.3s ease;
        border-left: 5px solid var(--page-ok9-secondary-color);
        display: flex;
        flex-direction: column;
        height: 100%;
    }

    .page-ok9__promo-item:hover {
        transform: translateY(-5px);
        box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
    }

    .page-ok9__promo-title {
        font-size: 1.4em;
        color: var(--page-ok9-primary-color);
        margin-bottom: 10px;
    }

    .page-ok9__promo-description {
        font-size: 0.95em;
        color: #666;
        margin-bottom: 15px;
        flex-grow: 1;
    }

    .page-ok9__promo-button {
        display: inline-block;
        background-color: var(--page-ok9-accent-color);
        color: var(--page-ok9-light-text-color);
        padding: 10px 20px;
        border-radius: 6px;
        text-decoration: none;
        font-weight: bold;
        font-size: 0.9em;
        transition: background-color 0.3s ease;
        align-self: flex-start; /* Căn chỉnh nút về phía đầu */
    }

    .page-ok9__promo-button:hover {
        background-color: #5cb85c;
    }

    @media (max-width: 768px) {
        .page-ok9__promo-list {
            grid-template-columns: 1fr;
            padding: 10px;
        }
        .page-ok9__promo-item {
            padding: 20px;
        }
        .page-ok9__promo-title {
            font-size: 1.2em;
        }
    }

    /* Phần Tại sao chọn */
    .page-ok9__features-list {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
        gap: 30px;
        padding: 20px;
    }

    .page-ok9__feature-item {
        background-color: var(--page-ok9-light-text-color);
        border-radius: 12px;
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
        padding: 30px;
        text-align: center;
        border-bottom: 4px solid var(--page-ok9-primary-color);
        transition: transform 0.3s ease;
    }

    .page-ok9__feature-item:hover {
        transform: translateY(-5px);
    }

    .page-ok9__feature-icon {
        font-size: 3em;
        color: var(--page-ok9-secondary-color);
        margin-bottom: 15px;
        display: block; /* Đảm bảo icon là block để căn lề */
    }

    .page-ok9__feature-title {
        font-size: 1.4em;
        color: var(--page-ok9-primary-color);
        margin-bottom: 10px;
    }

    .page-ok9__feature-description {
        font-size: 0.95em;
        color: #666;
    }

    @media (max-width: 768px) {
        .page-ok9__features-list {
            grid-template-columns: 1fr;
            padding: 10px;
        }
        .page-ok9__feature-item {
            padding: 25px;
        }
        .page-ok9__feature-title {
            font-size: 1.2em;
        }
    }

    /* Phần FAQ */
    .page-ok9__faq-list {
        max-width: 800px;
        margin: 0 auto;
        padding: 20px;
    }

    .page-ok9__faq-item {
        background-color: var(--page-ok9-light-text-color);
        border-radius: 10px;
        margin-bottom: 15px;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
        border: 1px solid var(--page-ok9-border-color);
    }

    .page-ok9__faq-question {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 15px 20px;
        cursor: pointer;
        user-select: none;
        background-color: #f0f0f0;
        border-radius: 10px;
        transition: background-color 0.3s ease;
    }

    .page-ok9__faq-question:hover {
        background-color: #e5e5e5;
    }

    .page-ok9__faq-question h3 {
        margin: 0;
        font-size: 1.1em;
        color: var(--page-ok9-text-color);
        pointer-events: none; /* Ngăn h3 chặn sự kiện click trên phần tử cha */
    }

    .page-ok9__faq-toggle {
        font-size: 1.5em;
        font-weight: bold;
        color: var(--page-ok9-primary-color);
        transition: transform 0.3s ease;
        pointer-events: none; /* Ngăn toggle chặn sự kiện click trên phần tử cha */
    }

    .page-ok9__faq-item.active .page-ok9__faq-toggle {
        transform: rotate(45deg); /* Chuyển '+' thành 'x' */
    }

    .page-ok9__faq-answer {
        max-height: 0;
        overflow: hidden;
        padding: 0 20px;
        transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), padding 0.4s ease, opacity 0.4s ease;
        opacity: 0;
        color: #555;
    }

    .page-ok9__faq-item.active .page-ok9__faq-answer {
        max-height: 2000px !important; /* Đủ lớn để chứa mọi nội dung */
        padding: 20px !important;
        opacity: 1;
    }

    .page-ok9__faq-answer p {
        margin-bottom: 10px;
        font-size: 0.95em;
    }

    @media (max-width: 768px) {
        .page-ok9__faq-list {
            padding: 10px;
        }
        .page-ok9__faq-question {
            padding: 12px 15px;
        }
        .page-ok9__faq-question h3 {
            font-size: 1em;
        }
        .page-ok9__faq-answer {
            padding: 0 15px;
        }
        .page-ok9__faq-item.active .page-ok9__faq-answer {
            padding: 15px !important;
        }
    }

    /* Phần Kết luận */
    .page-ok9__conclusion-content {
        text-align: center;
        max-width: 800px;
        margin: 0 auto;
        font-size: 1.1em;
    }

    .page-ok9__conclusion-content p {
        margin-bottom: 25px;
    }

    /* Điều chỉnh responsive chung cho danh sách và hình ảnh */
    .page-ok9 ul, .page-ok9 ol {
        list-style: none;
        padding: 0;
        margin: 0;
    }

    .page-ok9 ul li, .page-ok9 ol li {
        box-sizing: border-box;
    }

    .page-ok9 img {
        max-width: 100%;
        height: auto;
        display: block;
        box-sizing: border-box;
    }

    @media (max-width: 768px) {
        .page-ok9 ul, .page-ok9 ol {
            width: 100% !important;
            max-width: 100% !important;
            padding: 0 !important;
            margin-left: 0 !important;
            margin-right: 0 !important;
            box-sizing: border-box !important;
        }
        .page-ok9 ul li, .page-ok9 ol li {
            width: 100% !important;
            max-width: 100% !important;
            box-sizing: border-box !important;
            margin-left: 0 !important;
            margin-right: 0 !important;
            word-wrap: break-word !important;
            overflow-wrap: break-word !important;
            word-break: break-word !important;
        }
        .page-ok9 img {
            width: 100% !important;
            max-width: 100% !important;
            height: auto !important;
            box-sizing: border-box !important;
            overflow: hidden !important;
        }
    }