/* ======================= */
/* CÀI ĐẶT CHUNG & BIẾN MÀU */
/* ======================= */
/* ======================= */
/* CÀI ĐẶT CHUNG & BIẾN MÀU (PHIÊN BẢN HOÀN CHỈNH) */
/* ======================= */
:root {
    /* Hợp nhất từ bảng màu mới và cũ */
    --primary-color: #007bff; /* Giữ lại màu xanh dương chủ đạo của anh */
    --primary-color-light: #e6f0ff; /* Màu xanh nhạt tương ứng */
    
    --secondary-color: #6c757d;
    --heading-color: #2C3E50;
    --text-color: #343a40;
    
    --bg-color: #f8f9fa;      /* Nền xám rất nhạt cho các section */
    --surface-color: #ffffff; /* Nền trắng cho các thẻ, header, dropdown */
    --border-color: #dee2e6;  /* Màu viền nhất quán */

    --font-family: 'Be Vietnam Pro', sans-serif; /* Giữ lại font của anh */
}
body {
    font-family: 'Be Vietnam Pro', sans-serif;
    margin: 0;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white-color);
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: var(--primary-color);
}

h1, h2, h3, h4 {
    color: var(--dark-color);
}


/* ======================= */
/* HERO SECTION */
/* ======================= */
.hero {
    background-color: var(--light-color);
    padding: 80px 0;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto 2rem auto;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 5px;
    font-weight: 700;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--white-color);
    border: 1px solid var(--primary-color);
}

.btn-secondary {
    background-color: var(--white-color);
    color: var(--dark-color);
    border: 1px solid #ccc;
    margin-left: 10px;
}

/* ======================= */
/* FOOTER (PHIÊN BẢN NÂNG CẤP TOÀN DIỆN) */
/* ======================= */
.main-footer {
    background-color: var(--heading-color); /* Dùng màu xanh đen đậm */
    color: rgba(255, 255, 255, 0.7); /* Chữ màu trắng mờ */
    padding: 60px 0 0 0; /* Tăng padding trên, bỏ padding dưới */
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    padding-bottom: 40px;
}

.footer-column h3, .footer-column h4 {
    color: var(--surface-color); /* Màu trắng cho tiêu đề */
    margin-top: 0;
    margin-bottom: 20px;
}

.footer-column h3 {
    font-size: 1.5rem;
}

.footer-column h4 {
    font-size: 1.1rem;
}

.footer-column p {
    margin-bottom: 15px;
    line-height: 1.8;
}

.footer-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-column ul li {
    margin-bottom: 12px;
}

.footer-column ul a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: all 0.3s ease;
}

.footer-column ul a:hover {
    color: var(--surface-color);
    padding-left: 5px;
}

/* --- Social Icons --- */
.footer-social-icons {
    display: flex;
    gap: 15px;
    margin-bottom: 25px;
}

.social-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--surface-color);
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
}

.social-icon:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
}

/* --- Subscribe Form --- */
.footer-column .subscribe-title {
    margin-top: 0;
    margin-bottom: 10px;
    font-weight: 500;
}

.footer-subscribe-form {
    display: flex;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    overflow: hidden;
}

.footer-subscribe-form input {
    flex-grow: 1;
    background: none;
    border: none;
    padding: 12px 15px;
    color: var(--surface-color);
    font-family: var(--font-family);
    font-size: 0.95rem;
}

.footer-subscribe-form input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

.footer-subscribe-form button {
    background-color: var(--primary-color);
    border: none;
    color: var(--surface-color);
    padding: 0 15px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.footer-subscribe-form button:hover {
    background-color: #0056b3; /* Màu xanh đậm hơn khi hover */
}

/* --- Footer Bottom Bar --- */
.footer-bottom {
    text-align: center;
    padding: 20px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.5);
}/* ======================= */
/* EXPERTISE SECTION */
/* ======================= */
.expertise-section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
}

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr); /* Tạo layout 3 cột */
    gap: 30px; /* Khoảng cách giữa các cột */
}

.expertise-item {
    background-color: var(--light-color);
    padding: 30px;
    border-radius: 8px;
    text-align: center;
    border: 1px solid #e9ecef;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.expertise-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
}

.expertise-item i {
    font-size: 3rem; /* Kích thước icon */
    color: var(--primary-color);
    margin-bottom: 20px;
}

.expertise-item h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
}
/* ======================= */
/* BLOG SECTION */
/* ======================= */
.blog-section {
    padding: 80px 0;
    background-color: var(--light-color); /* Tạo sự phân tách với nền trắng */
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.blog-card {
    background-color: var(--white-color);
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    overflow: hidden; /* Đảm bảo ảnh bo góc theo thẻ */
    display: flex; /* Để thẻ có thể co giãn nội dung */
    flex-direction: column;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    color: var(--text-color); /* Ghi đè màu link mặc định */
}

.blog-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.blog-card-image {
    height: 200px;
    background-color: #e9ecef;
    object-fit: cover; /* Thêm dòng này */
    width: 100%;
}
.blog-card-content {
    padding: 25px;
    flex-grow: 1; /* Giúp phần content lấp đầy thẻ */
    display: flex;
    flex-direction: column;
}

.blog-meta {
    font-size: 0.85rem;
    color: var(--secondary-color);
    margin-bottom: 10px;
}

.blog-card h3 {
    font-size: 1.2rem;
    margin-top: 0;
    margin-bottom: 15px;
    flex-grow: 1; /* Đẩy chữ "Đọc thêm" xuống dưới cùng */
}

.read-more {
    font-weight: 700;
    color: var(--primary-color);
    align-self: flex-start; /* Căn lề trái */
}
/* ======================= */
/* PRODUCTS SECTION */
/* ======================= */
.products-section {
    padding: 80px 0;
    background-color: var(--white-color);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.product-card {
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 30px;
    display: flex;
    flex-direction: column;
    align-items: center; /* Căn giữa các item theo chiều ngang */
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
}

.product-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.product-card h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
}

.product-card p {
    flex-grow: 1; /* Đẩy nút bấm và giá xuống dưới */
    margin-bottom: 20px;
}

.product-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 15px;
}

/* Ghi đè lại style cho nút trong card này */
.product-card .btn {
    width: 80%; /* Cho nút bấm rộng hơn một chút */
}

.product-card .btn-primary {
    margin-top: 0; /* Reset margin nếu có */
}
/* ======================= */
/* CTA SECTION (SUBSCRIBE) */
/* ======================= */
.cta-section {
    background-color: var(--dark-color);
    color: var(--white-color);
    padding: 60px 0;
    text-align: center;
}

.cta-section h2 {
    color: var(--white-color);
    font-size: 2rem;
}

.subscribe-form {
    margin-top: 30px;
    display: flex;
    justify-content: center;
    align-items: center;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.subscribe-form input {
    width: 100%;
    padding: 14px 20px;
    border: 1px solid #ccc;
    border-radius: 5px 0 0 5px; /* Bo góc trái */
    border-right: none;
    font-size: 1rem;
}

.subscribe-form button {
    border-radius: 0 5px 5px 0; /* Bo góc phải */
    white-space: nowrap; /* Ngăn chữ "Đăng ký" xuống dòng */
}

/* ======================= */
/* CONTACT SECTION */
/* ======================= */
.contact-section {
    padding: 80px 0;
    background-color: var(--white-color);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: start;
}

.contact-details h3 {
    font-size: 1.5rem;
    margin-top: 0;
}

.contact-info-list {
    list-style: none;
    padding: 0;
    margin-top: 20px;
}

.contact-info-list li {
    margin-bottom: 15px;
    display: flex;
    align-items: center;
}

.contact-info-list i {
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-right: 15px;
    width: 20px; /* Đảm bảo các icon thẳng hàng */
}

.contact-form .form-group {
    margin-bottom: 20px;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 1rem;
    font-family: 'Be Vietnam Pro', sans-serif;
}

.contact-form button {
    width: 100%;
    padding: 15px;
    font-size: 1.1rem;
}
/* =================================== */
/* CSS CHO TRANG SANDBOX.HTML */
/* =================================== */

/* HERO SANDBOX */
.hero-sandbox {
    background-color: #F0F4F8; /* Màu nền xanh nhạt */
    padding: 80px 0;
    text-align: center;
}

.hero-stats {
    display: flex;
    justify-content: space-around;
    max-width: 900px;
    margin: 60px auto 0 auto;
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
    margin: 10px 20px;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-text {
    font-size: 1rem;
    color: var(--secondary-color);
}

/* CHALLENGES SECTION */
.challenges-section {
    padding: 80px 0;
    background-color: var(--white-color);
}

.challenges-section .section-title {
    line-height: 1.3;
}

.challenges-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr); /* 2 cột */
    gap: 40px;
    margin-top: 50px;
}

.challenge-item {
    display: flex;
    align-items: flex-start;
}

.challenge-number {
    font-size: 4rem;
    font-weight: 700;
    color: #e9ecef;
    line-height: 1;
    margin-right: 20px;
}

.challenge-content h3 {
    margin-top: 0;
    font-size: 1.3rem;
}

/* SOLUTIONS SECTION */
.solutions-section {
    padding: 80px 0;
    background-color: var(--light-color);
}

/* Tùy chỉnh lại form liên hệ cho gọn hơn */
.contact-section .form-group-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 20px;
}
/* =================================== */
/* CSS CHO TRANG PUSHSALE.HTML (PHIÊN BẢN CẢI TIẾN) */
/* =================================== */

/* HERO PUSHSALE */
.hero-pushsale {
    background: linear-gradient(to right, #141E30, #243B55); /* Giữ nguyên gradient nền */
    color: #FFFFFF; /* Đổi màu chữ mặc định thành trắng tinh */
    padding: 100px 0; /* Tăng khoảng đệm cho thoáng hơn */
    text-align: center;
}

/* Cải thiện độ tương phản cho tất cả văn bản trong khối */
.hero-pushsale h1, .hero-pushsale .subtitle, .hero-pushsale .feature-item {
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3); /* Thêm bóng mờ để chữ nổi bật */
}

.hero-pushsale h1 {
    color: #FFFFFF; /* Đảm bảo h1 luôn là màu trắng */
    font-size: 2.8rem; /* Tăng kích thước cho ấn tượng hơn */
}

.hero-pushsale .subtitle {
    font-size: 1.5rem;
    font-style: italic;
    color: #e0e8f3; /* Dùng màu trắng ngà, sáng hơn màu cũ */
    margin-top: -10px;
    margin-bottom: 40px; /* Tăng khoảng cách tới các feature */
}

.hero-features {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 20px; /* Tăng khoảng cách giữa các item */
    margin-bottom: 50px; /* Tăng khoảng cách tới nút bấm */
}

/* --- ĐÂY LÀ PHẦN THAY ĐỔI QUAN TRỌNG NHẤT --- */
.feature-item {
    background: transparent; /* Bỏ nền cũ */
    border: 1px solid rgba(255, 255, 255, 0.3); /* Dùng viền sáng thay thế */
    padding: 12px 24px; /* Tăng padding */
    border-radius: 50px; /* Bo tròn mạnh hơn để hiện đại hơn */
    font-weight: 500; /* Cho chữ đậm hơn một chút */
    transition: all 0.3s ease; /* Thêm hiệu ứng chuyển động mượt mà */
}

.feature-item:hover {
    background: rgba(255, 255, 255, 0.1); /* Hiện nền nhẹ khi di chuột */
    border-color: rgba(255, 255, 255, 0.7);
    transform: translateY(-3px); /* Nhấc nhẹ item lên */
}

.feature-item i {
    margin-right: 10px; /* Tăng khoảng cách icon và chữ */
    opacity: 0.8;
}
/* --- HẾT PHẦN THAY ĐỔI QUAN TRỌNG --- */

.hero-buttons .btn {
    padding: 15px 30px; /* Làm nút to hơn */
    font-size: 1.1rem;
}

/* SECRETS SECTION */
.secrets-section {
    padding: 80px 0;
    background-color: var(--white-color);
}

.secrets-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.secret-item {
    background-color: var(--light-color);
    padding: 30px;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
}

.secret-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
    margin-bottom: 15px;
}

.secret-item h3 {
    margin-top: 0;
}

.secret-item p {
    flex-grow: 1;
}

.secret-quote {
    font-weight: 700;
    font-style: italic;
    color: var(--secondary-color);
    margin-top: 20px;
    border-top: 1px solid #ddd;
    padding-top: 15px;
}

/* BENEFITS SECTION */
.benefits-section {
    padding: 80px 0;
    background-color: var(--light-color);
}

/* Tùy chỉnh cho danh sách lợi ích */
.benefits-section .product-card ul {
    text-align: left;
    padding-left: 20px; /* Thụt đầu dòng cho danh sách */
    margin-top: 0;
    flex-grow: 1;
}

.benefits-section .product-card ul li {
    margin-bottom: 8px;
}

/* Xóa bỏ p tag mặc định nếu không dùng */
.benefits-section .product-card p {
    display: none;
}
/* =================================== */
/* HEADER & NAVIGATION (PHIÊN BẢN HOÀN CHỈNH) */
/* =================================== */
.main-header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 999;
}

.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--heading-color);
}

.main-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}

.main-nav ul li {
    margin-left: 25px;
}

.main-nav ul li a {
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
}

.main-nav ul li a:hover,
.main-nav ul li a.active {
    color: var(--primary-color);
}

/* --- Dropdown Menu Styling --- */
.main-nav ul li.dropdown {
    position: relative;
}

.main-nav ul li.dropdown > a .fa-chevron-down {
    font-size: 0.7em;
    margin-left: 5px;
    transition: transform 0.3s ease;
}

.dropdown:hover > a .fa-chevron-down {
    transform: rotate(180deg);
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--surface-color);
    list-style: none;
    padding: 10px 0;
    margin: 0;
    margin-top: 15px;
    min-width: 240px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s ease;
}

.dropdown:hover .dropdown-menu {
    display: block;
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu li {
    width: 100%;
}

.dropdown-menu li a {
    display: block;
    padding: 12px 15px;
    color: var(--text-color);
    white-space: nowrap;
    text-decoration: none;
    transition: all 0.2s ease;
}

.dropdown-menu li a:hover,
.dropdown-menu li a.active {
    background-color: var(--primary-color-light);
    color: var(--primary-color);
    padding: 10px 15px;
    margin: 2px 8px;
    border-radius: 6px;
}

/* --- Mobile Menu Toggle (Hamburger Icon) --- */
.mobile-menu-toggle {
    display: none; /* Ẩn trên màn hình lớn */
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--heading-color);
}
/* ======================= */
/* SINGLE BLOG POST PAGE */
/* ======================= */
.post-detail-section {
    padding: 60px 0;
}

.article-container {
    max-width: 800px; /* Giới hạn chiều rộng để dễ đọc chữ */
}

.article-header {
    text-align: center;
    margin-bottom: 40px;
}

.article-meta {
    color: var(--secondary-color);
    font-weight: 500;
}

.article-header h1 {
    font-size: 2.8rem;
    margin: 10px 0;
}

.article-excerpt {
    font-size: 1.2rem;
    color: var(--secondary-color);
}

.article-featured-image {
    margin-bottom: 40px;
}

.article-featured-image img {
    width: 100%;
    height: auto;
    border-radius: 8px;
}

.article-content {
    font-size: 1.1rem;
    line-height: 1.8;
}

.article-content h2 {
    font-size: 1.8rem;
    margin-top: 50px;
    margin-bottom: 20px;
}

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

.article-content blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: 20px;
    margin: 30px 0;
    font-style: italic;
    font-size: 1.2rem;
    color: var(--secondary-color);
}

.article-content a {
    color: var(--primary-color);
    text-decoration: underline;
}
/* ======================= */
/* ABOUT ME PAGE           */
/* ======================= */
.about-hero-section {
    background-color: var(--dark-color);
    color: var(--white-color);
    text-align: center;
    padding: 80px 0;
}
.about-hero-section h1 {
    color: var(--white-color);
}
.about-hero-section p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 20px auto 0 auto;
    color: rgba(255, 255, 255, 0.8);
}

.story-section {
    padding: 80px 0;
    background-color: var(--white-color);
}

.story-grid {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 50px;
    align-items: center;
}

.story-image img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.story-content h2 {
    font-size: 2rem;
    margin-top: 0;
}

.story-content .signature {
    margin-top: 20px;
    font-family: 'Times New Roman', Times, serif; /* Hoặc một font chữ ký đẹp */
    font-size: 1.5rem;
    font-style: italic;
    color: var(--primary-color);
}

/* ======================= */
/* SANDBOX PAGE - UPGRADES */
/* ======================= */
.section-subtitle {
    text-align: center;
    max-width: 600px;
    margin: -20px auto 40px auto;
    color: var(--secondary-color);
}

/* Features Section */
.features-section {
    padding: 80px 0;
    background-color: var(--white-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.feature-box {
    border: 1px solid #e9ecef;
    padding: 30px;
    border-radius: 8px;
    text-align: center;
    transition: all 0.3s ease;
}

.feature-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
}

.feature-box i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.feature-box h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

/* Team Section */
.team-section {
    padding: 80px 0;
    background-color: var(--light-color);
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.team-member {
    text-align: center;
}

.team-member img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 20px;
    border: 4px solid var(--white-color);
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.team-member h3 {
    margin-bottom: 5px;
}

.team-title {
    color: var(--primary-color);
    font-weight: 700;
    margin-top: 0;
}

/* ======================= */
/* PUSHSALE PAGE - UPGRADES */
/* ======================= */

/* Testimonials Section */
.testimonials-section {
    padding: 80px 0;
    background-color: var(--white-color);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.testimonial-card {
    background-color: var(--light-color);
    padding: 30px;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
}

.testimonial-quote {
    flex-grow: 1;
    font-style: italic;
    margin-bottom: 20px;
    border-left: 3px solid var(--primary-color);
    padding-left: 15px;
}

.testimonial-author {
    display: flex;
    align-items: center;
}

.testimonial-author img {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    object-fit: cover;
    margin-right: 15px;
}

.author-info h4 {
    margin: 0;
}

.author-info p {
    margin: 0;
    font-size: 0.9rem;
    color: var(--secondary-color);
}

/* Pricing Section */
.pricing-section {
    padding: 80px 0;
    background-color: var(--light-color);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
    align-items: center;
}

.pricing-card {
    background-color: var(--white-color);
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 40px;
    text-align: center;
    transition: all 0.3s ease;
}

.pricing-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.pricing-card.popular {
    border-color: var(--primary-color);
    transform: scale(1.05);
    position: relative;
}

.popular-badge {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--primary-color);
    color: var(--white-color);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 700;
}

.pricing-card h3 {
    font-size: 1.3rem;
}

.pricing-card .price {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 20px 0;
}

.pricing-card .price span {
    font-size: 1rem;
    font-weight: 400;
    color: var(--secondary-color);
}

.pricing-card ul {
    list-style: none;
    padding: 0;
    margin: 30px 0;
    text-align: left;
}

.pricing-card ul li {
    margin-bottom: 15px;
}

.pricing-card ul li i {
    margin-right: 10px;
    color: var(--primary-color);
}

.pricing-card ul li i.fa-times-circle {
    color: #ccc;
}

/* ======================= */
/* BLOG LISTING PAGE       */
/* ======================= */
.blog-page-section {
    padding: 80px 0;
}

.blog-layout {
    display: grid;
    grid-template-columns: 2.5fr 1fr; /* 70% cho bài viết, 30% cho sidebar */
    gap: 50px;
}

.blog-post-list .blog-card-horizontal {
    display: flex;
    background-color: var(--white-color);
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    margin-bottom: 30px;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

.blog-post-list .blog-card-horizontal:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}

.blog-card-horizontal img {
    width: 250px;
    height: 100%;
    object-fit: cover;
}

.blog-card-horizontal .card-content {
    padding: 20px 30px;
}

.blog-card-horizontal h3 {
    margin-top: 5px;
    margin-bottom: 10px;
}

/* Sidebar */
.blog-sidebar .sidebar-widget {
    background-color: var(--light-color);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 30px;
}

.sidebar-widget h4 {
    margin-top: 0;
    padding-bottom: 10px;
    border-bottom: 1px solid #ddd;
}

.sidebar-widget ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-widget ul li a {
    text-decoration: none;
    color: var(--secondary-color);
    display: block;
    padding: 8px 0;
    transition: color 0.3s ease;
}

.sidebar-widget ul li a:hover {
    color: var(--primary-color);
}

.sidebar-widget.cta-widget {
    background-color: var(--dark-color);
    color: var(--white-color);
    text-align: center;
}
.sidebar-widget.cta-widget h4 {
    color: var(--white-color);
    border-bottom: 1px solid #555;
}
.sidebar-widget.cta-widget .btn {
    width: 100%;
}

/* Style cho category đang active trên sidebar */
.sidebar-widget ul li.active-category a {
    color: var(--primary-color);
    font-weight: 700;
}
/* ======================= */
/* LEAD MAGNET CTA BOX     */
/* ======================= */
.lead-magnet-cta {
    background-color: var(--light-color);
    border: 2px dashed var(--primary-color);
    border-radius: 8px;
    padding: 30px;
    margin: 40px 0;
    text-align: center;
}

.lead-magnet-cta h3 {
    margin-top: 0;
}

.lead-magnet-form {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin: 20px 0;
}

.lead-magnet-form input {
    width: 60%;
    padding: 10px 15px;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 1rem;
}

.lead-magnet-form button {
    white-space: nowrap; /* Ngăn nút bị xuống dòng */
}

.lead-magnet-cta .form-note {
    font-size: 0.9rem;
    color: var(--secondary-color);
    margin-bottom: 0;
}

/* ======================= */
/* RELATED POSTS & SHARING */
/* ======================= */

/* Social Sharing Section */
.social-share-section {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #e9ecef;
}

.social-share-section span {
    font-weight: 700;
}

.social-share-section .social-links {
    display: flex;
    gap: 10px;
}

.social-share-section .social-icon {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    color: var(--white-color);
    text-decoration: none;
    transition: opacity 0.3s ease;
}
.social-share-section .social-icon:hover {
    opacity: 0.8;
}

.social-icon.facebook { background-color: #1877F2; }
.social-icon.linkedin { background-color: #0A66C2; }
.social-icon.zalo { background-color: #0068FF; } /* Zalo blue */


/* Related Posts Section */
.related-posts-section {
    margin-top: 50px;
    padding-top: 40px;
    border-top: 1px solid #e9ecef;
}

.related-posts-section h2 {
    text-align: center;
    margin-bottom: 40px;
}

.related-posts-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}
.related-posts-grid .blog-card h3 {
    font-size: 1.1rem;
}
/* Placeholder card to keep grid alignment */
.related-posts-grid .blog-card.placeholder {
    background-color: transparent;
    box-shadow: none;
}

/* ======================= */
/* CONTACT PAGE            */
/* ======================= */
.contact-page-section {
    padding: 80px 0;
    background-color: var(--white-color);
}

.contact-layout {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 60px;
    background-color: var(--light-color);
    padding: 40px;
    border-radius: 8px;
}

.contact-info h3, .contact-form-wrapper h3 {
    margin-top: 0;
}

.contact-info .info-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 25px;
}
.contact-info .info-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-top: 5px;
}
.contact-info .info-item h4 {
    margin: 0 0 5px 0;
}
.contact-info .info-item p {
    margin: 0;
}
.contact-info .info-item a {
    text-decoration: none;
    color: var(--secondary-color);
}
.contact-info .info-item a:hover {
    color: var(--primary-color);
}

.contact-socials {
    margin-top: 30px;
    display: flex;
    gap: 15px;
}
.contact-socials .social-icon {
    width: 40px;
    height: 40px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: #e9ecef;
    color: var(--secondary-color);
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
}
.contact-socials .social-icon:hover {
    background-color: var(--primary-color);
    color: var(--white-color);
}

/* ======================= */
/* HIGH-INTENT CTA SECTION */
/* ======================= */
.high-intent-cta-section {
    background-color: var(--primary-color);
    color: var(--white-color);
    padding: 60px 0;
    text-align: center;
}
.high-intent-cta-section h2 {
    color: var(--white-color);
    margin-top: 0;
    margin-bottom: 15px;
}
.high-intent-cta-section p {
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto 30px auto;
    opacity: 0.9;
}
.high-intent-cta-section .btn-light {
    background-color: var(--white-color);
    color: var(--primary-color);
    padding: 15px 35px;
    font-size: 1.1rem;
    font-weight: 700;
}
.high-intent-cta-section .btn-light:hover {
    background-color: var(--light-color);
}
/* ======================= */
/* HOMEPAGE ENHANCEMENTS   */
/* ======================= */

/* --- Trusted By Section (SLIDER) --- */
.trusted-by-section {
    padding: 60px 0;
    background-color: var(--bg-color);
}

.trusted-by-section .section-subtitle {
    text-align: center;
    color: var(--secondary-color);
    font-weight: 500;
    margin-bottom: 40px;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
}

.slider-container {
    width: 100%;
    overflow: hidden;
    position: relative;
    -webkit-mask-image: linear-gradient(to right, transparent, black 20%, black 80%, transparent);
    mask-image: linear-gradient(to right, transparent, black 20%, black 80%, transparent);
}

.logos-slider {
    display: flex;
    animation: scroll 30s linear infinite;
}

.logos-slider:hover {
    animation-play-state: paused;
}

@keyframes scroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

.logo-item {
    flex-shrink: 0;
    width: 200px;
    padding: 0 20px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.logo-item img {
    max-width: 140px;
    height: auto;
    opacity: 0.7;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.logo-item img:hover {
    opacity: 1;
    transform: scale(1.1);
}

/* --- Stats Section --- */
.stats-section {
    background-color: var(--white-color);
    padding: 80px 0;
}
.stats-section h2 {
    text-align: center;
    margin-bottom: 50px;
}
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    text-align: center;
}
.stat-item .stat-number {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: block;
}
.stat-item .stat-label {
    font-size: 1.1rem;
    color: var(--secondary-color);
}

/* --- Testimonials Section --- */
.testimonials-section {
    padding: 80px 0;
    background-color: var(--light-color);
}
.testimonials-section h2 {
    text-align: center;
    margin-bottom: 50px;
}
.testimonials-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}
.testimonial-card {
    background-color: var(--white-color);
    padding: 30px;
    border-radius: 8px;
    border-left: 5px solid var(--primary-color);
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
}
.testimonial-quote {
    font-size: 1.1rem;
    font-style: italic;
    color: #495057;
    margin-top: 0;
    margin-bottom: 25px;
    position: relative;
}
.testimonial-quote::before {
    content: '“';
    font-family: Georgia, serif;
    font-size: 4rem;
    color: var(--primary-color);
    opacity: 0.2;
    position: absolute;
    top: -20px;
    left: -15px;
}
.testimonial-author {
    display: flex;
    align-items: center;
    gap: 15px;
}
.testimonial-author img {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    object-fit: cover;
}
.testimonial-author .author-name {
    font-weight: 700;
    display: block;
}
.testimonial-author .author-title {
    font-size: 0.9rem;
    color: #6c757d;
}

/* ============================= */
/* INTERACTIVE EXPERTISE ITEMS   */
/* ============================= */

/* Biến mỗi mục thành một link có thể click */
.expertise-item-link {
    text-decoration: none; /* Bỏ gạch chân */
    color: inherit; /* Giữ màu chữ gốc */
    display: block;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

/* Thêm hiệu ứng khi di chuột vào */
.expertise-item-link:hover .expertise-item {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

/* Đảm bảo item bên trong có style phù hợp */
.expertise-item {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
/* ======================= */
/* STRATEGIC THANK YOU PAGE */
/* ======================= */
.thank-you-section {
    padding: 80px 0;
    text-align: center;
}

.thank-you-icon {
    font-size: 5rem;
    color: #28a745; /* Màu xanh lá cây thành công */
    margin-bottom: 20px;
}

.thank-you-section h1 {
    margin-top: 0;
}

.thank-you-subtitle {
    font-size: 1.2rem;
    color: var(--secondary-color);
    max-width: 600px;
    margin: 0 auto 50px auto;
}

.next-steps {
    max-width: 700px;
    margin: 0 auto 50px auto;
    padding: 25px;
    background-color: var(--light-color);
    border-left: 5px solid var(--primary-color);
    text-align: left;
    border-radius: 0 8px 8px 0;
}
.next-steps h3 {
    margin-top: 0;
}

.while-you-wait {
    margin-top: 60px;
}

.resource-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 30px;
    text-align: left;
}

.resource-card {
    display: block;
    background-color: var(--white-color);
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
    border: 1px solid #eee;
}

.resource-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    border-color: var(--primary-color);
}

.resource-card i {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.resource-card h4 {
    margin: 0 0 10px 0;
}

.resource-card p {
    margin: 0;
    font-size: 0.95rem;
    color: var(--secondary-color);
}
/* ======================= */
/* RESOURCE LIBRARY PAGE   */
/* ======================= */
.resource-library-section {
    padding: 80px 0;
}

.resource-library-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.resource-item-card {
    background-color: var(--white-color);
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.07);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.resource-item-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.resource-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.resource-content {
    padding: 25px;
    display: flex;
    flex-direction: column;
    flex-grow: 1; /* Giúp nội dung co giãn */
}

.resource-type {
    display: inline-block;
    background-color: var(--primary-color-light);
    color: var(--primary-color);
    padding: 5px 10px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 700;
    margin-bottom: 15px;
    align-self: flex-start; /* Nằm ở đầu */
}

.resource-content h3 {
    margin-top: 0;
    margin-bottom: 10px;
}

.resource-content p {
    margin-bottom: 20px;
    flex-grow: 1; /* Đẩy button xuống dưới */
}

.resource-content .btn {
    width: 100%;
    text-align: center;
}
/* Tinh chỉnh Layout & UX */
.blog-card, .expertise-item, .resource-item-card, .testimonial-card, .product-card, .pricing-card {
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.blog-card:hover, .expertise-item-link:hover .expertise-item, .resource-item-card:hover, .testimonial-card:hover, .product-card:hover, .pricing-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.btn {
    border-radius: 8px;
    transition: all 0.3s ease;
}
/* =================================================================== */
/*                      CSS CHO TRANG BÁO GIÁ                          */
/* =================================================================== */

/* --- Page Hero Section Styling --- */
.page-hero-section {
    background-color: var(--primary-color-light);
    padding: 60px 0;
    text-align: center;
}
.page-hero-section h1 {
    color: var(--heading-color);
    margin-bottom: 10px;
}
.page-hero-section .section-subtitle {
    font-size: 1.1rem;
    color: var(--secondary-color);
    margin-top: 0;
}

/* --- Pricing Section Styling --- */
.pricing-section {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 30px;
    align-items: center;
}

.pricing-card {
    background-color: var(--surface-color);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 40px;
    display: flex;
    flex-direction: column;
    height: 100%;
    transition: all 0.3s ease;
}

.pricing-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.pricing-header {
    text-align: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 20px;
    margin-bottom: 30px;
}

.pricing-header h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.pricing-audience {
    color: var(--secondary-color);
    font-size: 0.9rem;
    min-height: 40px;
}

.pricing-features {
    list-style: none;
    margin-bottom: 30px;
    flex-grow: 1; /* Quan trọng: để đẩy footer xuống dưới */
}

.pricing-features li {
    margin-bottom: 15px;
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.pricing-features li i {
    color: var(--primary-color);
    margin-top: 5px;
}

.pricing-footer {
    text-align: center;
}

.pricing-footer .btn {
    width: 100%;
}

/* --- Styling for the POPULAR card --- */
.pricing-card.popular {
    border-color: var(--primary-color);
    transform: scale(1.05);
    position: relative;
    z-index: 10;
}

.popular-badge {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--primary-color);
    color: #fff;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 700;
}

/* --- FAQ Section Styling --- */
.faq-section {
    padding: 80px 0;
}

.faq-accordion {
    max-width: 800px;
    margin: 0 auto;
    border-top: 1px solid var(--border-color);
}

.faq-item {
    border-bottom: 1px solid var(--border-color);
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    text-align: left;
    padding: 20px 0;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--heading-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-question i {
    transition: transform 0.3s ease;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease, padding 0.5s ease;
}

.faq-answer p {
    padding-bottom: 20px;
    color: var(--secondary-color);
    line-height: 1.8;
}

.faq-item.active .faq-question i {
    transform: rotate(45deg);
}

.faq-item.active .faq-answer {
    max-height: 300px; /* Đủ lớn để chứa nội dung */
}
/* =================================================================== */
/*                     CSS CHO TRANG CASE STUDIES                      */
/* =================================================================== */

/* --- Trang chính (Case Studies Grid) --- */
.case-studies-section {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.case-study-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.case-study-card {
    display: block;
    text-decoration: none;
    background-color: var(--surface-color);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
}

.case-study-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 25px rgba(0,0,0,0.1);
}

.case-study-image {
    height: 220px;
    background-size: cover;
    background-position: center;
}

.case-study-content {
    padding: 25px;
}

.case-study-title {
    font-size: 1.25rem;
    color: var(--heading-color);
    margin-bottom: 10px;
}

.case-study-excerpt {
    color: var(--text-color);
    margin-bottom: 20px;
    line-height: 1.6;
}

.case-study-link {
    color: var(--primary-color);
    font-weight: 700;
}

.case-study-link i {
    margin-left: 5px;
    transition: margin-left 0.3s ease;
}

.case-study-card:hover .case-study-link i {
    margin-left: 10px;
}

/* --- Trang chi tiết (Case Study Detail) --- */
.case-study-detail {
    padding: 80px 0;
}

.case-study-detail-header {
    text-align: center;
    margin-bottom: 60px;
}

.case-study-main-image {
    margin-bottom: 60px;
    border-radius: 12px;
    overflow: hidden;
}

.case-study-main-image img {
    width: 100%;
}

.project-overview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    background-color: var(--primary-color-light);
    padding: 30px;
    border-radius: 12px;
    margin-bottom: 60px;
}

.overview-item h4 {
    color: var(--secondary-color);
    font-size: 0.9rem;
    margin-bottom: 5px;
    text-transform: uppercase;
}

.overview-item p {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--heading-color);
}

.overview-item.result-highlight p {
    color: var(--primary-color);
    font-size: 1.5rem;
}

.case-study-body {
    max-width: 800px;
    margin: 0 auto;
}

.content-section {
    margin-bottom: 40px;
}

.content-section h2 {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--primary-color);
    display: inline-block;
}

.content-section ul, .content-section ol {
    padding-left: 20px;
    line-height: 1.8;
}

.result-section ul li {
    list-style: none;
    font-size: 1.1rem;
    margin-bottom: 10px;
}
.result-section ul li i {
    color: var(--primary-color);
    margin-right: 10px;
}

.case-study-cta {
    text-align: center;
    background-color: var(--bg-color);
    padding: 50px;
    border-radius: 12px;
    margin-top: 60px;
}

/* =================================== */
/* MEDIA QUERIES - MOBILE RESPONSIVE */
/* =================================== */

/* Áp dụng cho màn hình nhỏ hơn 992px (Tablet) */
@media (max-width: 992px) {
    .blog-grid,
    .products-grid,
    .testimonials-grid,
    .case-study-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .secrets-grid,
    .pricing-grid {
        grid-template-columns: 1fr;
    }
    .features-grid, .team-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .blog-layout, .contact-layout {
        grid-template-columns: 1fr;
    }
    .pricing-card {
        margin-bottom: 30px;
    }
    .pricing-card.popular {
        transform: scale(1);
    }
    .related-posts-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Áp dụng cho màn hình nhỏ hơn 768px (Mobile) */
@media (max-width: 768px) {
    /* --- Header & Hamburger Menu --- */
    .main-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--surface-color);
        flex-direction: column;
        width: 100%;
        box-shadow: 0 8px 16px rgba(0,0,0,0.1);
        border-top: 1px solid var(--border-color);
        padding: 10px 0;
    }

    .main-nav.mobile-active {
        display: flex;
    }

    .main-nav ul {
        flex-direction: column;
        width: 100%;
    }

    .main-nav ul li {
        margin: 0;
        text-align: left;
    }
    
    .main-nav ul li a {
        padding: 15px 20px;
        display: block;
        width: 100%;
        border-bottom: 1px solid var(--bg-color);
    }

    /* --- Mobile Dropdown (ĐÃ SỬA LỖI) --- */
    .main-nav ul li.dropdown .dropdown-menu {
        position: static;
        display: block; /* QUAN TRỌNG: Luôn là block để transition hoạt động */
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.4s ease-out;
        visibility: visible;
        opacity: 1;
        transform: none;
        box-shadow: none;
        border: none;
        margin-top: 0;
        padding: 0;
        background-color: #f8f9fa;
    }

    .main-nav ul li.dropdown.dropdown-active > .dropdown-menu {
        max-height: 500px; /* Chiều cao đủ lớn để chứa các mục con */
    }
    
    .main-nav ul li.dropdown.dropdown-active > a .fa-chevron-down {
        transform: rotate(180deg);
    }

    .dropdown-menu li a {
        padding-left: 40px;
    }

    .mobile-menu-toggle {
        display: block;
    }

    /* --- Chỉnh lại các layout grid thành 1 cột --- */
    .expertise-grid,
    .blog-grid,
    .products-grid,
    .contact-grid,
    .challenges-grid,
    .secrets-grid,
    .features-grid,
    .team-grid,
    .testimonials-grid,
    .pricing-grid,
    .stats-grid,
    .related-posts-grid,
    .story-grid,
    .resource-library-grid,
    .footer-grid,
    .case-study-grid,
    .project-overview {
        grid-template-columns: 1fr;
    }
    
    /* --- Tối ưu Font và Khoảng cách --- */
    .hero h1, .hero-sandbox h1, .hero-pushsale h1, .article-header h1 {
        font-size: 2.2rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .hero p, .hero-sandbox p, .hero-pushsale .subtitle {
        font-size: 1.1rem;
    }

    .btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
    
    section {
        padding: 60px 0;
    }

    /* --- Tối ưu các thành phần cụ thể --- */
    .footer-grid {
        text-align: center;
    }
    .footer-column {
        margin-bottom: 30px;
    }
    .footer-social-icons, .footer-subscribe-form {
        justify-content: center;
    }

    .blog-card-horizontal, .lead-magnet-form {
        flex-direction: column;
    }

    .blog-card-horizontal img {
        width: 100%;
        height: 200px;
    }

    .lead-magnet-form input {
        width: 100%;
    }
    
    .contact-layout {
        padding: 20px;
    }
    
    /* --- Logo Slider trên mobile --- */
    .logos-slider {
        animation-name: scroll-mobile;
    }

    @keyframes scroll-mobile {
        0% { transform: translateX(0); }
        100% { transform: translateX(-50%); }
    }

    .logo-item {
        width: 150px;
        padding: 0 15px;
    }
}