/* ============================================
   HẠTBÀNG CÔN ĐẢO HUỲNH THẢO - STYLESHEET
   Website: hatbangcondao.com
   © 2024 All rights reserved
   ============================================ */

/* ============================================
   1. RESET & VARIABLES
   ============================================ */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors */
    --primary-color: #7B4397;
    --secondary-color: #4CAF50;
    --accent-color: #FF5722;
    --tiktok-pink: #FE2C55;
    --zalo-green: #25D366;
    --text-color: #333333;
    --text-light: #666666;
    --bg-white: #FFFFFF;
    --bg-light: #F5F5F5;
    --bg-dark: #1a1a1a;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #7B4397 0%, #DC2430 100%);
    --gradient-hero: linear-gradient(135deg, rgba(123, 67, 151, 0.9) 0%, rgba(76, 175, 80, 0.9) 100%);
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.2);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Typography */
    --font-family: 'Roboto', 'Open Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;
    
    /* Transitions */
    --transition-base: all 0.3s ease;
    --transition-fast: all 0.15s ease;
}

html {
    scroll-behavior: smooth;
    font-size: var(--font-size-base);
}

body {
    font-family: var(--font-family);
    color: var(--text-color);
    line-height: var(--line-height-base);
    background-color: var(--bg-white);
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-base);
}

ul {
    list-style: none;
}

/* ============================================
   2. UTILITY CLASSES
   ============================================ */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    color: var(--primary-color);
    position: relative;
    padding-bottom: var(--spacing-md);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-base);
    text-align: center;
    white-space: nowrap;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--bg-white);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--secondary-color);
    color: var(--bg-white);
}

.btn-secondary:hover {
    background: #45a049;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-messenger {
    background: #0084FF;
    color: var(--bg-white);
}

.btn-messenger:hover {
    background: #0073e6;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-tiktok {
    background: var(--tiktok-pink);
    color: var(--bg-white);
    font-size: 1.2rem;
    padding: var(--spacing-md) var(--spacing-xl);
}

.btn-tiktok:hover {
    background: #e6244c;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-order {
    background: var(--accent-color);
    color: var(--bg-white);
}

.btn-order:hover {
    background: #e64a19;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-order.featured {
    background: var(--gradient-primary);
    font-size: 1.1rem;
}

/* ============================================
   3. HEADER (STICKY)
   ============================================ */

.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--bg-white);
    box-shadow: var(--shadow-md);
    z-index: 1000;
    transition: var(--transition-base);
}

.header.hide {
    transform: translateY(-100%);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) 0;
}

.logo img {
    height: 60px;
    width: auto;
}

.nav-menu ul {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-menu a {
    font-weight: 500;
    color: var(--text-color);
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition-base);
}

.nav-menu a:hover::after {
    width: 100%;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.btn-zalo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--zalo-green);
    color: var(--bg-white);
    border-radius: 50px;
    font-weight: 600;
}

.btn-zalo:hover {
    background: #20c75c;
    transform: scale(1.05);
}

.btn-cta {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--accent-color);
    color: var(--bg-white);
    border: none;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-base);
}

.btn-cta:hover {
    background: #e64a19;
    transform: scale(1.05);
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--primary-color);
    cursor: pointer;
}

/* ============================================
   4. HERO SECTION
   ============================================ */

.hero-section {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-3xl) 0;
    margin-top: 80px;
    overflow: hidden;
}

/* Hero Background Slider */
.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.hero-bg-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 2s ease-in-out;
}

.hero-bg-slide.active {
    opacity: 1;
}

.hero-bg-slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

/* Hero Overlay - Gradient để text dễ đọc */
.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        135deg,
        rgba(123, 67, 151, 0.85) 0%,
        rgba(76, 175, 80, 0.75) 50%,
        rgba(123, 67, 151, 0.85) 100%
    );
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: var(--bg-white);
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    text-shadow: 2px 2px 8px rgba(0, 0, 0, 0.5);
    animation: fadeInUp 1s ease;
}

.hero-title span {
    display: block;
    font-size: 2rem;
    margin-top: var(--spacing-sm);
}

.hero-features {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.1rem;
    font-weight: 600;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.5);
}

.feature-item i {
    color: var(--secondary-color);
    font-size: 1.3rem;
}

.hero-cta {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

/* ============================================
   5. FEATURES SECTION
   ============================================ */

.features-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
}

.feature-card {
    text-align: center;
    padding: var(--spacing-xl);
    background: var(--bg-white);
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    font-size: 2rem;
    color: var(--bg-white);
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.feature-card p {
    color: var(--text-light);
}

/* ============================================
   6. INTRO SECTION
   ============================================ */

.intro-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-light);
}

.intro-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.intro-text p {
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.intro-text strong {
    color: var(--primary-color);
}

.product-info-table {
    margin-top: var(--spacing-xl);
}

.product-info-table table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.product-info-table th,
.product-info-table td {
    padding: var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
}

.product-info-table th {
    background: var(--gradient-primary);
    color: var(--bg-white);
    font-weight: 600;
}

.product-info-table tr:last-child td {
    border-bottom: none;
}

.intro-image img {
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
}

/* ============================================
   7. PROCESS SECTION
   ============================================ */

.process-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-white);
}

.process-timeline {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-md);
    position: relative;
}

.process-timeline::before {
    content: '';
    position: absolute;
    top: 50px;
    left: 10%;
    right: 10%;
    height: 2px;
    background: var(--gradient-primary);
    z-index: 0;
}

.process-step {
    flex: 1;
    text-align: center;
    position: relative;
    z-index: 1;
}

.step-number {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 30px;
    height: 30px;
    background: var(--gradient-primary);
    color: var(--bg-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.step-icon {
    width: 100px;
    height: 100px;
    margin: 0 auto var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-white);
    border: 3px solid var(--primary-color);
    border-radius: 50%;
    font-size: 2.5rem;
    color: var(--primary-color);
    transition: var(--transition-base);
}

.process-step:hover .step-icon {
    background: var(--gradient-primary);
    color: var(--bg-white);
    transform: scale(1.1);
}

.process-step h3 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.process-step p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ============================================
   8. PRICING SECTION
   ============================================ */

.pricing-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-light);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
}

.pricing-card {
    background: var(--bg-white);
    border-radius: 15px;
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
    position: relative;
    overflow: hidden;
}

.pricing-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.pricing-card.featured {
    border: 3px solid var(--accent-color);
    background: linear-gradient(135deg, #fff9f5 0%, #ffffff 100%);
}

.badge {
    position: absolute;
    top: 20px;
    right: -30px;
    background: var(--accent-color);
    color: var(--bg-white);
    padding: 5px 40px;
    font-weight: 700;
    transform: rotate(45deg);
    box-shadow: var(--shadow-md);
}

.product-image {
    width: 100%;
    height: 250px;
    margin-bottom: var(--spacing-md);
    border-radius: 10px;
    overflow: hidden;
    background: var(--bg-light);
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-base);
}

.pricing-card:hover .product-image img {
    transform: scale(1.1);
}

.pricing-card h3 {
    font-size: 1.4rem;
    margin-bottom: var(--spacing-md);
    color: var(--primary-color);
}

.price {
    margin-bottom: var(--spacing-md);
}

.price-old {
    text-decoration: line-through;
    color: var(--text-light);
    font-size: 1.2rem;
    margin-right: var(--spacing-xs);
}

.price-amount {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-color);
}

.price-unit {
    font-size: 1rem;
    color: var(--text-light);
}

.savings {
    background: #fff3cd;
    color: #856404;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 20px;
    display: inline-block;
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

.features-list {
    margin: var(--spacing-lg) 0;
}

.features-list li {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
    color: var(--text-color);
}

.features-list i {
    color: var(--secondary-color);
    margin-top: 3px;
}

/* ============================================
   9. TIKTOK SECTION
   ============================================ */

.tiktok-section {
    padding: var(--spacing-3xl) 0;
    background: linear-gradient(135deg, #fff0f5 0%, #ffffff 100%);
}

.tiktok-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.tiktok-banner img {
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
}

.tiktok-price {
    margin-bottom: var(--spacing-md);
}

.current-price {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--tiktok-pink);
    margin-right: var(--spacing-sm);
}

.original-price {
    text-decoration: line-through;
    color: var(--text-light);
    font-size: 1.5rem;
    margin-right: var(--spacing-sm);
}

.discount {
    background: var(--tiktok-pink);
    color: var(--bg-white);
    padding: 5px 10px;
    border-radius: 5px;
    font-weight: 700;
}

.tiktok-rating {
    margin-bottom: var(--spacing-lg);
}

.stars {
    font-size: 1.2rem;
    margin-right: var(--spacing-sm);
}

.tiktok-features {
    margin: var(--spacing-lg) 0;
}

.tiktok-features li {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-size: 1.1rem;
}

.tiktok-features i {
    color: var(--tiktok-pink);
}

.tiktok-note {
    margin-top: var(--spacing-md);
    font-style: italic;
    color: var(--text-light);
}

/* ============================================
   10. VIDEO SECTION
   ============================================ */

.video-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-white);
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.video-card {
    text-align: center;
}

.video-link {
    display: block;
    text-decoration: none;
    color: inherit;
}

.video-thumbnail {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: var(--transition-base);
    aspect-ratio: 9/16;
    background: var(--bg-dark);
}

.video-thumbnail:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-base);
}

.video-link:hover .video-thumbnail img {
    transform: scale(1.1);
}

.video-play-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.5);
    transition: var(--transition-base);
}

.video-link:hover .video-play-overlay {
    background: rgba(0, 0, 0, 0.7);
}

.play-button {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--tiktok-pink);
    border-radius: 50%;
    font-size: 2rem;
    color: var(--bg-white);
    margin-bottom: var(--spacing-md);
    transition: var(--transition-base);
    box-shadow: 0 5px 20px rgba(254, 44, 85, 0.5);
}

.video-link:hover .play-button {
    transform: scale(1.2);
    box-shadow: 0 8px 30px rgba(254, 44, 85, 0.7);
}

.play-text {
    color: var(--bg-white);
    font-weight: 600;
    font-size: 1.1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.video-caption {
    margin-top: var(--spacing-md);
    font-weight: 600;
    color: var(--text-color);
}

.video-footer {
    text-align: center;
    margin-top: var(--spacing-xl);
    font-size: 1.2rem;
    font-weight: 600;
}

.video-footer a {
    color: var(--tiktok-pink);
    text-decoration: underline;
}

/* ============================================
   11. TESTIMONIALS SECTION
   ============================================ */

.testimonials-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-light);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.testimonial-card {
    background: var(--bg-white);
    padding: var(--spacing-xl);
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
    text-align: center;
}

.testimonial-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.avatar {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.stars {
    color: #FFD700;
    margin-bottom: var(--spacing-sm);
}

.testimonial-card h4 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.testimonial-card p {
    color: var(--text-light);
    font-style: italic;
    line-height: 1.6;
}

.testimonials-summary {
    text-align: center;
    margin-top: var(--spacing-xl);
    font-size: 1.5rem;
}

/* ============================================
   12. COMMITMENT SECTION
   ============================================ */

.commitment-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-white);
}

.commitment-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.commitment-card {
    text-align: center;
    padding: var(--spacing-xl);
    background: var(--bg-light);
    border-radius: 15px;
    transition: var(--transition-base);
}

.commitment-card:hover {
    background: var(--bg-white);
    box-shadow: var(--shadow-lg);
}

.commitment-icon {
    width: 100px;
    height: 100px;
    margin: 0 auto var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    font-size: 2.5rem;
    color: var(--bg-white);
}

.commitment-card h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.commitment-card p {
    color: var(--text-light);
}

/* ============================================
   13. FAQ SECTION
   ============================================ */

.faq-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-light);
}

.faq-list {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-white);
    margin-bottom: var(--spacing-md);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: var(--transition-base);
}

.faq-question:hover {
    background: var(--bg-light);
}

.faq-question h3 {
    font-size: 1.1rem;
    color: var(--primary-color);
    flex: 1;
}

.faq-question i {
    color: var(--primary-color);
    transition: var(--transition-base);
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 1000px;
}

.faq-answer p,
.faq-answer ul {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    color: var(--text-color);
    line-height: 1.8;
}

.faq-answer ul {
    padding-left: var(--spacing-xl);
}

.faq-answer li {
    list-style: disc;
    margin-bottom: var(--spacing-xs);
}

.faq-answer strong {
    color: var(--primary-color);
}

.faq-answer a {
    color: var(--primary-color);
    text-decoration: underline;
}

/* ============================================
   14. ORDER SECTION
   ============================================ */

.order-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-white);
    text-align: center;
}

.order-content {
    max-width: 700px;
    margin: 0 auto;
}

.btn-order-main {
    background: var(--accent-color);
    color: var(--bg-white);
    font-size: 1.5rem;
    padding: var(--spacing-lg) var(--spacing-2xl);
    border: none;
    border-radius: 50px;
    cursor: pointer;
    font-weight: 700;
    transition: var(--transition-base);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.btn-order-main:hover {
    background: #e64a19;
    transform: scale(1.05);
    box-shadow: var(--shadow-xl);
}

.order-options {
    margin-top: var(--spacing-xl);
}

.order-options p {
    margin-bottom: var(--spacing-sm);
    font-size: 1.1rem;
}

.phone-link {
    color: var(--primary-color);
    font-weight: 700;
    text-decoration: underline;
}

/* ============================================
   15. FOOTER
   ============================================ */

.footer {
    background: var(--bg-dark);
    color: var(--bg-white);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-logo img {
    height: 80px;
    margin-bottom: var(--spacing-md);
}

.footer-col h4 {
    color: var(--bg-white);
    margin-bottom: var(--spacing-md);
    font-size: 1.2rem;
}

.footer-col p {
    color: #cccccc;
    margin-bottom: var(--spacing-xs);
}

.footer-col ul li {
    margin-bottom: var(--spacing-sm);
}

.footer-col a {
    color: #cccccc;
    transition: var(--transition-base);
}

.footer-col a:hover {
    color: var(--secondary-color);
}

.contact-info li {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.contact-info i {
    color: var(--secondary-color);
}

.social-icons {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.social-icons a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    font-size: 1.2rem;
    transition: var(--transition-base);
}

.social-icons a:hover {
    transform: scale(1.2);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid #444;
    color: #cccccc;
}

/* ============================================
   16. MODAL (GOOGLE FORM POPUP)
   ============================================ */

.modal {
    display: none;
    position: fixed;
    z-index: 9999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    animation: fadeIn 0.3s ease;
}

.modal-content {
    position: relative;
    background-color: var(--bg-white);
    margin: 2% auto;
    width: 90%;
    max-width: 800px;
    height: 90vh;
    border-radius: 15px;
    overflow: hidden;
    animation: slideDown 0.3s ease;
}

.modal-content iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.close-btn {
    position: absolute;
    top: 10px;
    right: 20px;
    font-size: 2rem;
    color: var(--text-color);
    cursor: pointer;
    z-index: 10000;
    background: var(--bg-white);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
}

.close-btn:hover {
    background: var(--accent-color);
    color: var(--bg-white);
    transform: rotate(90deg);
}

/* ============================================
   17. BACK TO TOP BUTTON
   ============================================ */

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    color: var(--bg-white);
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-base);
    z-index: 999;
    box-shadow: var(--shadow-lg);
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

/* ============================================
   18. ANIMATIONS
   ============================================ */

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* AOS Animation Support */
[data-aos] {
    opacity: 0;
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos].aos-animate {
    opacity: 1;
}

[data-aos="fade-up"] {
    transform: translateY(30px);
}

[data-aos="fade-up"].aos-animate {
    transform: translateY(0);
}

[data-aos="fade-right"] {
    transform: translateX(-30px);
}

[data-aos="fade-right"].aos-animate {
    transform: translateX(0);
}

[data-aos="fade-left"] {
    transform: translateX(30px);
}

[data-aos="fade-left"].aos-animate {
    transform: translateX(0);
}

/* ============================================
   19. RESPONSIVE DESIGN
   ============================================ */

/* Tablet (768px - 1024px) */
@media (max-width: 1024px) {
    .section-title {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-title span {
        font-size: 1.5rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-title span {
        font-size: 1.8rem;
    }
    
    .intro-content,
    .tiktok-content {
        grid-template-columns: 1fr;
    }
    
    .process-timeline {
        flex-wrap: wrap;
    }
    
    .process-timeline::before {
        display: none;
    }
}

/* Mobile (< 768px) */
@media (max-width: 768px) {
    :root {
        --font-size-base: 14px;
        --spacing-3xl: 3rem;
        --spacing-2xl: 2rem;
    }
    
    .header-content {
        padding: var(--spacing-sm) 0;
    }
    
    .logo img {
        height: 50px;
    }
    
    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background: var(--bg-white);
        transition: var(--transition-base);
        z-index: 999;
        box-shadow: var(--shadow-lg);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-menu ul {
        flex-direction: column;
        padding: var(--spacing-xl);
        gap: var(--spacing-md);
    }
    
    .header-actions .btn-zalo,
    .header-actions .btn-cta {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .hero-section {
        min-height: 70vh;
        padding: var(--spacing-2xl) 0;
    }
    
    .hero-title {
        font-size: 1.8rem;
    }
    
    .hero-title span {
        font-size: 1.2rem;
    }
    
    .hero-features {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .feature-item {
        font-size: 1rem;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: stretch;
    }
    
    .hero-cta .btn {
        width: 100%;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .features-grid,
    .pricing-grid,
    .testimonials-grid,
    .commitment-grid {
        grid-template-columns: 1fr;
    }
    
    .process-timeline {
        flex-direction: column;
        gap: var(--spacing-xl);
    }
    
    .intro-content,
    .tiktok-content {
        grid-template-columns: 1fr;
    }
    
    .product-info-table table {
        font-size: 0.9rem;
    }
    
    .product-info-table th,
    .product-info-table td {
        padding: var(--spacing-sm);
    }
    
    .product-image {
        height: 200px;
    }
    
    .video-grid {
        grid-template-columns: 1fr;
    }
    
    .btn-order-main {
        font-size: 1.2rem;
        padding: var(--spacing-md) var(--spacing-lg);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        width: 95%;
        height: 85vh;
        margin: 5% auto;
    }
    
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}

/* Small Mobile (< 480px) */
@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero-title {
        font-size: 1.5rem;
    }
    
    .hero-title span {
        font-size: 1rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .feature-card,
    .pricing-card,
    .testimonial-card {
        padding: var(--spacing-md);
    }
    
    .btn {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.9rem;
    }
    
    .current-price {
        font-size: 2rem;
    }
    
    .original-price {
        font-size: 1.2rem;
    }
}

/* ============================================
   20. PRINT STYLES
   ============================================ */

@media print {
    .header,
    .hero-cta,
    .btn,
    .modal,
    .back-to-top,
    .mobile-menu-toggle {
        display: none !important;
    }
    
    body {
        font-size: 12pt;
    }
    
    .section-title {
        page-break-after: avoid;
    }
    
    .pricing-card,
    .testimonial-card,
    .faq-item {
        page-break-inside: avoid;
    }
}