/* ========================================
   Global Styles
   ======================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fafafa;
    background-image: url('pattern.png');
    background-repeat: repeat;
    background-attachment: fixed;
    background-size: 50px 50px;
}

/* ========================================
   Header Section
   ======================================== */

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2rem 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    text-align: center;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.site-title {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: 1px;
}

/* ========================================
   Navigation Bar
   ======================================== */

.navbar {
    background-color: #fff;
    border-bottom: 2px solid #667eea;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.nav-list {
    list-style: none;
    display: flex;
    justify-content: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.nav-list li {
    margin: 0 2rem;
}

.nav-link {
    display: block;
    padding: 1rem 0;
    color: #333;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease, border-bottom 0.3s ease;
    border-bottom: 3px solid transparent;
}

.nav-link:hover {
    color: #667eea;
    border-bottom-color: #667eea;
}

/* ========================================
   Main Container
   ======================================== */

.container {
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    gap: 2rem;
    padding: 2rem 1rem;
    min-height: calc(100vh - 300px);
}

/* ========================================
   Main Content Area
   ======================================== */

.main-content {
    flex: 1;
    background-color: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    order: 1;
}

.article {
    max-width: 900px;
}

.article-title {
    font-size: 2rem;
    color: #333;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.article-meta {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #e0e0e0;
    font-size: 0.9rem;
    color: #666;
}

.article-date,
.article-author {
    display: flex;
    align-items: center;
}

.article-body {
    color: #444;
    line-height: 1.8;
}

.article-body p {
    margin-bottom: 1.5rem;
    text-align: justify;
}

.article-body h3 {
    font-size: 1.5rem;
    color: #333;
    margin-top: 2rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #667eea;
}

/* ========================================
   Sidebar (Positioned on the Right)
   ======================================== */

.sidebar {
    width: 250px;
    background-color: #fff;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    height: fit-content;
    position: sticky;
    top: 80px;
    order: 2;
}

.sidebar-title {
    font-size: 1.3rem;
    color: #667eea;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #667eea;
}

.sidebar-list {
    list-style: none;
}

.sidebar-list li {
    margin-bottom: 0.5rem;
}

.sidebar-link {
    display: block;
    padding: 0.75rem 1rem;
    color: #333;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.sidebar-link:hover {
    background-color: #667eea;
    color: white;
}

.sidebar-link.active {
    background-color: #667eea;
    color: white;
}

/* ========================================
   Footer Section
   ======================================== */

.footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 2rem 1rem;
    margin-top: 3rem;
    border-top: 4px solid #667eea;
}

.footer-content p {
    margin: 0;
    font-size: 0.95rem;
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 768px) {
    .container {
        flex-direction: column;
        gap: 1.5rem;
    }

    .sidebar {
        width: 100%;
        position: static;
        order: 2;
    }

    .main-content {
        order: 1;
    }

    .nav-list {
        flex-wrap: wrap;
    }

    .nav-list li {
        margin: 0 1rem;
    }

    .nav-link {
        padding: 0.75rem 0;
    }

    .site-title {
        font-size: 1.8rem;
    }

    .article-title {
        font-size: 1.5rem;
    }

    .article-meta {
        flex-direction: column;
        gap: 0.5rem;
    }

    .main-content {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 1.5rem 0;
    }

    .site-title {
        font-size: 1.5rem;
    }

    .nav-list {
        padding: 0;
    }

    .nav-list li {
        margin: 0 0.75rem;
        font-size: 0.9rem;
    }

    .nav-link {
        padding: 0.5rem 0;
    }

    .container {
        padding: 1rem 0.5rem;
    }

    .main-content {
        padding: 1rem;
    }

    .article-title {
        font-size: 1.3rem;
    }

    .article-body h3 {
        font-size: 1.2rem;
    }
}