/* Reset và Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4361ee;
    --primary-dark: #3a56d4;
    --secondary-color: #7209b7;
    --accent-color: #f72585;
    --dark-color: #1a1a2e;
    --light-color: #f8f9fa;
    --gray-color: #6c757d;
    --gray-light: #e9ecef;
    --success-color: #4cc9f0;
    --warning-color: #f8961e;
    --danger-color: #e63946;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --border-radius: 12px;
    --container-width: 1200px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 {
    font-size: 3.5rem;
}

h2 {
    font-size: 2.5rem;
}

h3 {
    font-size: 1.75rem;
}

p {
    margin-bottom: 1rem;
    color: var(--gray-color);
}

.highlight {
    color: var(--primary-color);
}

.gradient-text {
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    display: inline-block;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    border: 2px solid transparent;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    white-space: nowrap;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

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

.btn-outline {
    background-color: transparent;
    color: var(--dark-color);
    border-color: var(--gray-light);
}

.btn-outline:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.1rem;
}

.btn-block {
    width: 100%;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
    padding: 20px 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--dark-color);
}

.logo i {
    color: var(--primary-color);
    font-size: 1.8rem;
}

.logo-highlight {
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--dark-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    padding: 8px 0;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
}

.nav-actions {
    display: flex;
    gap: 1rem;
}

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

/* Hero Section */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(135deg, #f5f7ff 0%, #e3e9ff 100%);
    position: relative;
    overflow: hidden;
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--gray-color);
    margin-bottom: 2rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
}

.hero-stats {
    display: flex;
    gap: 3rem;
}

.stat-item h3 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-item p {
    font-size: 0.9rem;
    color: var(--gray-color);
}

/* AI Interface Preview */
.ai-interface {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transform: perspective(1000px) rotateY(-10deg);
    transition: var(--transition);
}

.ai-interface:hover {
    transform: perspective(1000px) rotateY(-5deg);
}

.ai-header {
    background: var(--dark-color);
    color: white;
    padding: 15px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.ai-dots {
    display: flex;
    gap: 8px;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dot.red { background: #ff5f57; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #28ca42; }

.ai-title {
    font-weight: 600;
    font-size: 0.9rem;
}

.ai-messages {
    padding: 20px;
    min-height: 300px;
}

.message {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
    opacity: 0;
    animation: fadeIn 0.5s forwards;
}

.message.user {
    justify-content: flex-end;
}

.message.user .text {
    background: var(--primary-color);
    color: white;
    border-radius: 18px 18px 0 18px;
}

.message.bot .text {
    background: var(--gray-light);
    color: var(--dark-color);
    border-radius: 18px 18px 18px 0;
}

.message .text {
    padding: 12px 16px;
    max-width: 70%;
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--gray-light);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.ai-input {
    padding: 20px;
    border-top: 1px solid var(--gray-light);
    display: flex;
    gap: 10px;
}

.ai-input input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid var(--gray-light);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.send-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary-color);
    color: white;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.send-btn:hover {
    background: var(--primary-dark);
    transform: rotate(15deg);
}

.typing-indicator {
    display: flex;
    gap: 5px;
    padding: 10px 20px;
}

.typing-indicator span {
    width: 8px;
    height: 8px;
    background: var(--gray-color);
    border-radius: 50%;
    animation: typing 1s infinite;
}

.typing-indicator span:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-indicator span:nth-child(3) {
    animation-delay: 0.4s;
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

/* Features Section */
.features {
    padding: 100px 0;
    background: white;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--gray-color);
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    padding: 2rem;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 2rem;
    color: white;
}

/* About Section */
.about {
    padding: 100px 0;
    background: linear-gradient(135deg, #f8f9ff 0%, #f0f2ff 100%);
}

.about-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.dashboard-preview {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.dashboard-header {
    background: var(--dark-color);
    color: white;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.dashboard-stats {
    display: flex;
    gap: 20px;
}

.dashboard-content {
    padding: 30px;
    display: flex;
    gap: 20px;
    justify-content: center;
}

.chart-container {
    text-align: center;
}

.chart {
    width: 60px;
    border-radius: 10px 10px 0 0;
    margin-bottom: 10px;
}

.about-features {
    margin: 2rem 0;
}

.about-feature {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    align-items: flex-start;
}

.about-feature i {
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-top: 3px;
}

/* Pricing Section */
.pricing {
    padding: 100px 0;
    background: white;
}

.pricing-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.pricing-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 2rem;
    position: relative;
    transition: var(--transition);
}

.pricing-card:hover {
    transform: translateY(-10px);
}

.pricing-card.popular {
    border: 2px solid var(--primary-color);
}

.popular-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 6px 20px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}

.pricing-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--gray-light);
}

.price {
    margin: 1rem 0;
    color: var(--dark-color);
}

.amount {
    font-size: 3rem;
    font-weight: 800;
}

.period {
    color: var(--gray-color);
    font-size: 1rem;
}

.pricing-features {
    list-style: none;
    margin-bottom: 2rem;
}

.pricing-features li {
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.pricing-features i.fa-check {
    color: var(--primary-color);
}

.pricing-features i.fa-times {
    color: var(--gray-color);
}

/* CTA Section */
.cta {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.cta-container {
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta .highlight {
    color: #ffd166;
}

.cta p {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.9);
    max-width: 600px;
    margin: 0 auto 3rem;
}

.cta-form {
    max-width: 500px;
    margin: 0 auto;
}

.input-group {
    display: flex;
    gap: 10px;
    margin-bottom: 1rem;
}

.input-group input {
    flex: 1;
    padding: 15px 20px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.form-note {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.7);
}

/* Footer */
.footer {
    background: var(--dark-color);
    color: white;
    padding: 80px 0 0;
}

.footer-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col h4 {
    color: white;
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: 0.8rem;
}

.footer-col a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-col a:hover {
    color: white;
}

.footer-description {
    color: rgba(255, 255, 255, 0.7);
    margin: 1rem 0;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: var(--transition);
}

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

.footer-bottom {
    background: rgba(0, 0, 0, 0.2);
    padding: 20px 0;
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
}

/* Back to top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary-color);
    color: white;
    border: none;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

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

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes typing {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0) translateX(-50%);
    }
    40% {
        transform: translateY(-10px) translateX(-50%);
    }
    60% {
        transform: translateY(-5px) translateX(-50%);
    }
}

/* Responsive Styles */
@media (max-width: 1024px) {
    h1 {
        font-size: 3rem;
    }
    
    h2 {
        font-size: 2.2rem;
    }
    
    .hero-container,
    .about-container {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .hero-image {
        order: -1;
    }
}

@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }
    
    .nav-menu {
        position: fixed;
        top: 80px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 2rem;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
        z-index: 999;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-actions {
        display: none;
    }
    
    .hero {
        padding: 140px 0 60px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .features-grid,
    .pricing-cards {
        grid-template-columns: 1fr;
    }
    
    .input-group {
        flex-direction: column;
    }
    
    .ai-interface {
        transform: none;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.8rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .btn-large {
        padding: 14px 24px;
        font-size: 1rem;
    }
    
    .footer-container {
        grid-template-columns: 1fr;
    }
}