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

:root {
    --primary-color: #17a2b8;
    --secondary-color: #ebe7d9;
    --text-color: #1a1a1a;
    --text-light: #666;
    --border-color: #d4cec0;
    --bg-color: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

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

/* Navbar */
.navbar {
    background: linear-gradient(135deg, #17a2b8 0%, #138496 100%);
    border-bottom: 3px solid #0f5f6f;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 4px 12px rgba(23, 162, 184, 0.2);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: white;
    text-decoration: none;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s;
    padding: 8px 16px;
    border-radius: 6px;
}

.nav-links a:hover {
    background-color: rgba(255, 255, 255, 0.2);
    color: #ebe7d9;
}

/* Article */
main {
    padding: 40px 0;
    min-height: calc(100vh - 200px);
}

.article-header {
    margin-bottom: 40px;
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 20px;
    background: linear-gradient(135deg, rgba(23, 162, 184, 0.05) 0%, rgba(235, 231, 217, 0.1) 100%);
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(23, 162, 184, 0.1);
}

.article-header h1 {
    font-size: 42px;
    margin-bottom: 10px;
    line-height: 1.2;
}

.article-date {
    color: var(--text-light);
    font-size: 14px;
}

/* Article Layout */
.article-layout {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 40px;
}

.article {
    background: linear-gradient(135deg, #ffffff 0%, #f9f8f7 100%);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 8px 24px rgba(23, 162, 184, 0.12);
    border: 1px solid #e8dfd5;
}

.sidebar {
    position: sticky;
    top: 80px;
    height: fit-content;
}

.article-content {
    flex: 1;
}

/* Table of Contents */
.toc {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #f9f7f0 100%);
    padding: 25px;
    border-radius: 12px;
    font-size: 14px;
    box-shadow: 0 4px 12px rgba(23, 162, 184, 0.15);
    border-left: 4px solid var(--primary-color);
}

.toc h3 {
    margin-bottom: 15px;
    font-size: 16px;
}

.toc ul {
    list-style: none;
    padding-left: 15px;
}

.toc li {
    margin: 8px 0;
}

.toc a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s;
}

.toc a:hover {
    text-decoration: underline;
}

/* Content Styling */
.article-content h2,
.article-content h3,
.article-content h4 {
    margin-top: 30px;
    margin-bottom: 15px;
    line-height: 1.3;
}

.article-content h2 {
    font-size: 28px;
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 10px;
}

.article-content h3 {
    font-size: 22px;
}

.article-content h4 {
    font-size: 18px;
}

.article-content p {
    margin-bottom: 15px;
}

.article-content a {
    color: var(--primary-color);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s;
}

.article-content a:hover {
    border-bottom-color: var(--primary-color);
}

.article-content code {
    background: linear-gradient(135deg, #f0ebe3 0%, #f5f3ed 100%);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
    border: 1px solid #d4cec0;
}

.article-content pre {
    background: linear-gradient(135deg, #f9f7f0 0%, #f5f3ed 100%);
    padding: 20px;
    border-radius: 12px;
    overflow-x: auto;
    margin: 15px 0;
    border-left: 4px solid var(--primary-color);
    box-shadow: 0 4px 12px rgba(23, 162, 184, 0.1);
}

.article-content pre code {
    background-color: transparent;
    padding: 0;
    color: var(--text-color);
}

.article-content ul,
.article-content ol {
    margin-left: 30px;
    margin-bottom: 15px;
}

.article-content li {
    margin-bottom: 8px;
}

.article-content blockquote {
    border-left: 4px solid var(--primary-color);
    padding: 20px;
    padding-left: 25px;
    margin: 20px 0;
    color: var(--text-light);
    font-style: italic;
    background-color: var(--secondary-color);
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(23, 162, 184, 0.1);
}

.article-content img {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    margin: 20px 0;
    box-shadow: 0 4px 16px rgba(23, 162, 184, 0.2);
    border: 2px solid var(--secondary-color);
}

.article-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(23, 162, 184, 0.1);
}

.article-content th,
.article-content td {
    padding: 14px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.article-content th {
    background: linear-gradient(135deg, #17a2b8 0%, #138496 100%);
    color: white;
    font-weight: 600;
}

.article-content tr:hover {
    background-color: var(--secondary-color);
}

/* Footer */
.footer {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #f9f7f0 100%);
    border-top: 3px solid var(--primary-color);
    padding: 40px 0;
    text-align: center;
    color: var(--text-light);
    box-shadow: 0 -4px 12px rgba(23, 162, 184, 0.1);
}

/* Responsive */
@media (max-width: 768px) {
    .article-layout {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
    }

    .nav-links {
        gap: 15px;
    }

    .article-header h1 {
        font-size: 28px;
    }

    .article-content h2 {
        font-size: 22px;
    }
}