/* Reset and Global Styles */
html, body {
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif;
    background: linear-gradient(to bottom, #f0f4f7, #e8eaf6);
    color: #333;
    overflow-x: hidden;
}

body {
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

*, *::before, *::after {
    box-sizing: border-box;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Montserrat', sans-serif;
    font-weight: bold;
    color: #2c3e50;
    margin-top: 1.5em;
    margin-bottom: 0.5em;
    line-height: 1.2;
}

h2 { font-size: 2.2rem; }
h3 { font-size: 1.8rem; }
h4 { font-size: 1.5rem; }
p { margin-bottom: 1em; font-size: 1.1rem; color: #555; }

/* Layout and Structure */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.header {
    background: linear-gradient(to right, #6a89cc, #8e44ad);
    padding: 20px 0;
    margin-bottom: 30px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo {
    color: white;
    font-size: 2rem;
    font-weight: bold;
    text-decoration: none;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
}

nav li {
    margin-left: 20px;
}

nav a {
    text-decoration: none;
    color: white;
    font-size: 1.1rem;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

nav a:hover {
    opacity: 1;
}

.hero {
    padding: 50px 20px;
    background: linear-gradient(135deg, #a8c0ff, #3ab7bf);
    color: white;
    text-align: center;
    border-radius: 10px;
    margin-bottom: 30px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.hero h1 {
    color: white;
    font-size: 3rem;
    margin-bottom: 20px;
}

.hero p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto 30px;
}

.cta-button {
    display: inline-block;
    padding: 12px 30px;
    background-color: #ff6f61;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    font-size: 1.1rem;
    transition: background-color 0.3s ease;
}

.cta-button:hover {
    background-color: #e0524a;
}

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

.card {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.08);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.15);
}

.card-image-container {
    overflow: hidden;
    border-bottom: 1px solid #eee;
}

.card-image {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s ease;
}

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

.card-content {
    padding: 20px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    flex-grow: 1;
}

.card-title {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: #34495e;
}

.card-description {
    font-size: 1rem;
    color: #777;
    margin-bottom: 20px;
    flex-grow: 1;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
}

.card-tag {
    background-color: #e7f1fd;
    color: #4979b6;
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 0.9rem;
    margin-right: 5px;
    margin-bottom: 5px;
}

.article-section {
    background-color: #f9f9f9;
    padding: 40px 20px;
    border-radius: 8px;
    box-shadow: 0 3px 9px rgba(0,0,0,0.05);
    margin-bottom: 30px;
}

.article-section h2 {
    color: #333;
    border-bottom: 2px solid #eee;
    padding-bottom: 10px;
    margin-bottom: 20px;
}

.article-section h3 {
    color: #444;
    margin-top: 2em;
    margin-bottom: 1em;
}

.article-section p, .article-section li, .article-section td {
    font-size: 1rem;
    color: #666;
}

.article-section ul {
    padding-left: 25px;
    margin-bottom: 1em;
}

.article-section li {
    margin-bottom: 0.5em;
    list-style-type: square;
}

.article-section table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
}

.article-section th, .article-section td {
    border: 1px solid #ddd;
    padding: 8px;
    text-align: left;
}

.article-section th {
    background-color: #f2f2f2;
    font-weight: bold;
}

.article-section pre {
    background-color: #f0f0f0;
    padding: 15px;
    border-radius: 6px;
    overflow-x: auto;
    font-size: 0.9rem;
    line-height: 1.4;
    tab-size: 4;
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: monospace, monospace;
    color: #222;
    border: 1px solid #ccc;
}

.article-section code {
    font-family: monospace, monospace;
}

.footer {
    text-align: center;
    padding: 30px 0;
    color: #777;
    border-top: 1px solid #eee;
    font-size: 0.9rem;
}

.reference-text {
    text-align: center;
    color: #888;
    margin-bottom: 20px;
    font-style: italic;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .container {
        padding: 15px;
    }
    .hero {
        padding: 40px 15px;
    }
    .hero h1 {
        font-size: 2.5rem;
    }
    .hero p {
        font-size: 1.1rem;
    }
    .card-section {
        gap: 20px;
    }
    .card-content {
        padding: 15px;
    }
    .card-title {
        font-size: 1.3rem;
        margin-bottom: 10px;
    }
    .card-description {
        font-size: 0.95rem;
        margin-bottom: 15px;
    }
    .article-section {
        padding: 30px 15px;
    }
    .article-section h2 {
        font-size: 2rem;
    }
    .article-section h3 {
        font-size: 1.6rem;
    }
    .article-section p, .article-section li, .article-section td, .article-section pre {
        font-size: 0.95rem;
    }
}

@media (max-width: 768px) {
    .header-inner {
        flex-direction: column;
        align-items: center;
    }
    nav ul {
        margin-top: 15px;
        flex-direction: column;
        text-align: center;
    }
    nav li {
        margin-left: 0;
        margin-bottom: 10px;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .hero p {
        font-size: 1rem;
    }
    .card-section {
        grid-template-columns: 1fr;
    }
    .article-section h2 {
        font-size: 1.8rem;
    }
    .article-section h3 {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.8rem;
    }
    .hero p {
        font-size: 0.9rem;
    }
    .card-title {
        font-size: 1.2rem;
    }
    .card-description {
        font-size: 0.9rem;
    }
    .article-section h2 {
        font-size: 1.6rem;
    }
    .article-section h3 {
        font-size: 1.4rem;
    }
    .article-section p, .article-section li, .article-section td, .article-section pre {
        font-size: 0.9rem;
    }
}

@media (max-width: 320px) {
    .hero h1 {
        font-size: 1.6rem;
    }
}