/* Global Styles */
:root {
    --primary-color: #3a86ff;
    --secondary-color: #8338ec;
    --dark-color: #333;
    --light-color: #f4f4f4;
    --success-color: #28a745;
    --danger-color: #dc3545;
}

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

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

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

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

ul {
    list-style: none;
}

img {
    width: 100%;
}

/* Container */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
    overflow: hidden;
}

/* Header */
header {
    background-color: var(--dark-color);
    color: #fff;
    padding: 1rem 0;
}

header h1 {
    margin-bottom: 1rem;
}

header nav ul {
    display: flex;
    flex-wrap: wrap;
}

header nav ul li {
    margin-right: 1rem;
}

header nav ul li a {
    color: #fff;
    padding: 0.5rem;
}

header nav ul li a:hover {
    color: var(--primary-color);
}

/* Main Content */
main {
    padding: 2rem 0;
}

section {
    margin-bottom: 2rem;
}

h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

h3 {
    margin-bottom: 0.5rem;
}

p {
    margin-bottom: 1rem;
}

/* Cards */
.card-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.card {
    background: #fff;
    padding: 1.5rem;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

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

/* Buttons */
.btn {
    display: inline-block;
    background: var(--primary-color);
    color: #fff;
    padding: 0.5rem 1.5rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    margin-top: 1rem;
    transition: background 0.3s ease;
}

.btn:hover {
    background: var(--secondary-color);
    color: #fff;
}

.cta {
    text-align: center;
    margin: 2rem 0;
}

/* Article Styles */
article {
    background: #fff;
    padding: 2rem;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

article h2 {
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
}

article h3 {
    color: var(--secondary-color);
    margin: 1.5rem 0 0.5rem;
}

article h4 {
    margin: 1.2rem 0 0.5rem;
}

article ul, article ol {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

article ul li, article ol li {
    margin-bottom: 0.5rem;
}

blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: 1rem;
    margin: 1rem 0;
    font-style: italic;
}

/* Table of Contents */
.toc {
    background: #fff;
    padding: 1.5rem;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

.toc h3 {
    margin-top: 0;
}

.toc ul {
    margin-left: 1rem;
}

/* Footer */
footer {
    background: var(--dark-color);
    color: #fff;
    text-align: center;
    padding: 1rem 0;
}

/* Responsive */
@media (max-width: 768px) {
    .card-container {
        grid-template-columns: 1fr;
    }
    
    header nav ul {
        flex-direction: column;
    }
    
    header nav ul li {
        margin-bottom: 0.5rem;
    }
}