/* Base Styles */
:root {
    --primary-color: #4CAF50;
    --secondary-color: #FF5722;
    --dark-color: #333;
    --light-color: #f4f4f4;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: #fff;
}

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

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

ul {
    list-style: none;
}

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

.btn {
    display: inline-block;
    background: var(--primary-color);
    color: #fff;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
}

.btn:hover {
    background: #3d8b40;
    transform: translateY(-3px);
    box-shadow: var(--box-shadow);
}

/* Header */
header {
    background-color: #fff;
    box-shadow: var(--box-shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
}

.logo h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
}

nav ul {
    display: flex;
}

nav ul li {
    margin-left: 20px;
}

nav ul li a {
    font-weight: 600;
    padding: 10px 5px;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

nav ul li a:hover,
nav ul li a.active {
    border-bottom: 2px solid var(--primary-color);
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('https://images.unsplash.com/photo-1519003722824-194d4455a60c?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=80');
    background-size: cover;
    background-position: center;
    height: 60vh;
    color: #fff;
    display: flex;
    align-items: center;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 10px;
}

.hero h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    font-weight: 400;
}

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

/* Overview Section */
.overview {
    padding: 60px 0;
    background-color: var(--light-color);
}

.overview h2 {
    text-align: center;
    margin-bottom: 40px;
    font-size: 2rem;
}

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.card {
    background: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
    text-align: center;
    transition: var(--transition);
}

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

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

.card h3 {
    margin-bottom: 15px;
    font-size: 1.5rem;
}

/* Key Visualizations Section */
.key-visualizations {
    padding: 60px 0;
}

.key-visualizations h2 {
    text-align: center;
    margin-bottom: 40px;
    font-size: 2rem;
}

.visualization-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 30px;
}

.visualization {
    background: #fff;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
    overflow: hidden;
    transition: var(--transition);
}

.visualization:hover {
    transform: translateY(-5px);
}

.visualization h3 {
    padding: 20px;
    text-align: center;
    background-color: var(--primary-color);
    color: #fff;
}

.visualization img {
    width: 100%;
    height: auto;
    display: block;
}

.visualization .btn {
    display: block;
    margin: 20px auto;
    width: 150px;
    text-align: center;
}

/* CTA Section */
.cta {
    background-color: var(--primary-color);
    color: #fff;
    padding: 60px 0;
    text-align: center;
}

.cta h2 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.cta p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.cta .btn {
    background-color: #fff;
    color: var(--primary-color);
}

.cta .btn:hover {
    background-color: #f0f0f0;
}

/* Footer */
footer {
    background-color: var(--dark-color);
    color: #fff;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.footer-section h3 {
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul li a {
    color: #ddd;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #444;
}

/* Content Pages */
.page-header {
    background-color: var(--primary-color);
    color: #fff;
    padding: 60px 0;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.page-content {
    padding: 60px 0;
}

.page-content h2 {
    margin-bottom: 30px;
    font-size: 2rem;
    color: var(--primary-color);
}

.page-content h3 {
    margin: 30px 0 15px;
    font-size: 1.5rem;
}

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

.page-content ul, .page-content ol {
    margin-bottom: 20px;
    padding-left: 20px;
}

.page-content li {
    margin-bottom: 10px;
}

.page-content img {
    display: block;
    margin: 30px auto;
    max-width: 100%;
    border-radius: 5px;
    box-shadow: var(--box-shadow);
}

.page-content table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 30px;
}

.page-content th, .page-content td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

.page-content th {
    background-color: var(--primary-color);
    color: #fff;
}

.page-content tr:hover {
    background-color: #f5f5f5;
}

/* Responsive Design */
@media (max-width: 768px) {
    header .container {
        flex-direction: column;
    }
    
    nav ul {
        margin-top: 20px;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    nav ul li {
        margin: 0 10px 10px;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero h2 {
        font-size: 1.2rem;
    }
    
    .visualization-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 500px) {
    .cards {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}