/* --- Global Styles --- */
:root {
    --primary-color: #0d253f; /* Xanh Navy đậm */
    --accent-color: #e67e22;   /* Màu cam năng động */
    --text-color: #333;
    --light-bg: #f9f9f9;
    --white: #ffffff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Open Sans', sans-serif;
}

h1, h2, h3, h4 {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
}

body {
    line-height: 1.6;
    color: var(--text-color);
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

.section-padding {
    padding: 80px 0;
}

.text-center { text-align: center; }
.bg-light { background-color: var(--light-bg); }

/* --- Navbar --- */
.navbar {
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 30px;
}

.nav-links a {
    font-weight: 600;
    font-size: 0.95rem;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--accent-color);
}

.btn-nav {
    background-color: var(--accent-color);
    color: var(--white) !important;
    padding: 8px 20px;
    border-radius: 5px;
    transition: background 0.3s;
}

.btn-nav:hover {
    background-color: #d35400;
}

.menu-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* --- Hero Section --- */
.hero {
    height: 100vh;
    background-image: url('https://images.unsplash.com/photo-1509062522246-3755977927d7?ixlib=rb-1.2.1&auto=format&fit=crop&w=1920&q=80');
    background-size: cover;
    background-position: center;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--white);
}

.hero-overlay {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(13, 37, 63, 0.7); /* Overlay màu xanh tối */
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    padding: 20px;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 5px;
    font-weight: 600;
    transition: all 0.3s;
    margin: 5px;
}

.btn-primary {
    background-color: var(--accent-color);
    color: var(--white);
    border: 2px solid var(--accent-color);
}

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

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--white);
    color: var(--white);
}

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

/* --- About Section --- */
.row {
    display: flex;
    align-items: center;
    gap: 50px;
}

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

.col-image, .col-text {
    flex: 1;
}

.section-title {
    font-size: 2.2rem;
    color: var(--primary-color);
    margin-bottom: 20px;
    position: relative;
    display: inline-block;
}

/* Gạch chân dưới tiêu đề */
.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--accent-color);
    margin-top: 10px;
}

.text-center .section-title::after {
    margin: 10px auto;
}

.lead-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: #555;
    margin-bottom: 15px;
}

.feature-list li {
    margin: 10px 0;
    display: flex;
    align-items: center;
}

.feature-list i {
    color: var(--accent-color);
    margin-right: 10px;
    font-size: 1.2rem;
}

/* --- Stats Section --- */
.stats {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 60px 0;
    text-align: center;
}

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

.stat-item h3 {
    font-size: 3rem;
    color: var(--accent-color);
    margin-bottom: 5px;
}

/* --- Programs Cards --- */
.cards-container {
    margin-top: 40px;
}

.card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
    transition: transform 0.3s;
}

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

.card-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.card h3 {
    margin-bottom: 15px;
}

/* --- Footer --- */
.site-footer {
    background-color: #1a1a1a;
    color: #ccc;
    padding: 60px 0 20px;
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin-bottom: 40px;
}

.footer-info, .footer-contact {
    flex: 1;
    min-width: 300px;
    margin-bottom: 20px;
}

.footer-info h3 {
    color: var(--white);
    margin-bottom: 15px;
    font-size: 1.5rem;
}

.footer-contact h4 {
    color: var(--white);
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 20px;
}

.contact-item i {
    color: var(--accent-color);
    font-size: 1.2rem;
    margin-right: 15px;
    margin-top: 5px;
}

.contact-item a {
    color: #ccc;
    transition: color 0.3s;
}

.contact-item a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #333;
    font-size: 0.9rem;
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
    .menu-toggle { display: block; }
    
    .nav-links {
        position: fixed;
        right: -100%;
        top: 70px;
        height: calc(100vh - 70px);
        background-color: var(--white);
        flex-direction: column;
        width: 60%;
        padding-top: 50px;
        transition: right 0.4s ease;
        box-shadow: -2px 0 5px rgba(0,0,0,0.1);
    }

    .nav-links.active { right: 0; }

    .hero h1 { font-size: 2.5rem; }
    
    .row { flex-direction: column; }
    
    .grid-3 { grid-template-columns: 1fr; }
    
    .footer-content { flex-direction: column; }
}