/* ==========================================
   CSS Reset & Base Styles
   ========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    
    /* Spacing */
    --container-width: 1200px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-light);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ==========================================
   Header & Navigation
   ========================================== */
.header {
    background-color: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo i {
    font-size: 1.75rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--primary-color);
}

.nav-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-dark);
}

/* ==========================================
   Hero Section
   ========================================== */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-xl) 0;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.6s ease;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
    animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    animation: fadeInUp 0.6s ease 0.4s both;
}

/* ==========================================
   Buttons
   ========================================== */
.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: white;
    color: var(--primary-color);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background-color: white;
    color: var(--primary-color);
}

/* ==========================================
   Section Styles
   ========================================== */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-xl);
    color: var(--text-dark);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    margin: var(--spacing-md) auto 0;
    border-radius: 2px;
}

/* ==========================================
   Categories Section
   ========================================== */
.categories {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-white);
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.category-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 2px solid var(--border-color);
    text-align: center;
    transition: all var(--transition-base);
    cursor: pointer;
}

.category-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.category-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.category-name {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: var(--spacing-xs);
}

.category-count {
    color: var(--text-light);
    font-size: 0.875rem;
}

/* ==========================================
   Blog Section
   ========================================== */
.blog {
    padding: var(--spacing-xl) 0;
}

.blog-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.blog-filters {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.filter-select {
    padding: 0.5rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background-color: white;
    color: var(--text-dark);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    cursor: pointer;
    transition: border-color var(--transition-fast);
}

.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.search-box {
    position: relative;
}

.search-box i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-light);
}

.search-box input {
    padding: 0.5rem 1rem 0.5rem 2.5rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background-color: white;
    color: var(--text-dark);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    width: 250px;
    transition: border-color var(--transition-fast);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.blog-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    cursor: pointer;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.blog-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.blog-card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

.blog-card-content {
    padding: var(--spacing-md);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.blog-card-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    width: fit-content;
}

.blog-card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

.blog-card-summary {
    color: var(--text-light);
    font-size: 0.875rem;
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
    flex: 1;
}

.blog-card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    color: var(--text-light);
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--border-color);
}

.blog-card-date,
.blog-card-views {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* ==========================================
   Pagination
   ========================================== */
.pagination {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xl);
}

.pagination button {
    padding: 0.5rem 1rem;
    border: 2px solid var(--border-color);
    background: white;
    color: var(--text-dark);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.pagination button:hover:not(:disabled) {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.pagination button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.pagination button.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* ==========================================
   About Section
   ========================================== */
.about {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-white);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.about-text h3 {
    font-size: 1.75rem;
    color: var(--text-dark);
    margin-bottom: var(--spacing-md);
}

.about-text p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--bg-light);
    color: var(--text-dark);
    font-size: 1.25rem;
    transition: all var(--transition-base);
    text-decoration: none;
}

.social-link:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-3px);
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
}

.stat-card {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.9;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    background-color: var(--text-dark);
    color: white;
    padding: var(--spacing-lg) 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer-links {
    display: flex;
    gap: var(--spacing-md);
}

.footer-links a {
    color: white;
    text-decoration: none;
    transition: opacity var(--transition-fast);
}

.footer-links a:hover {
    opacity: 0.7;
}

/* ==========================================
   Modal
   ========================================== */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.7);
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background-color: white;
    margin: 3% auto;
    padding: 0;
    max-width: 900px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    animation: slideUp 0.3s ease;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-close {
    color: var(--text-light);
    float: right;
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
    padding: var(--spacing-md);
    line-height: 1;
    transition: color var(--transition-fast);
}

.modal-close:hover {
    color: var(--text-dark);
}

.article-detail {
    padding: var(--spacing-xl);
}

.article-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: var(--spacing-md);
    line-height: 1.3;
}

.article-meta {
    display: flex;
    gap: var(--spacing-md);
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.article-body {
    color: var(--text-dark);
    line-height: 1.8;
    font-size: 1.125rem;
}

.article-body p {
    margin-bottom: var(--spacing-md);
}

.article-body h2 {
    font-size: 1.75rem;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    color: var(--text-dark);
}

.article-body h3 {
    font-size: 1.5rem;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
}

.article-body ul,
.article-body ol {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.article-body li {
    margin-bottom: var(--spacing-xs);
}

.article-body code {
    background-color: var(--bg-light);
    padding: 0.2rem 0.4rem;
    border-radius: var(--radius-sm);
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.article-body pre {
    background-color: var(--text-dark);
    color: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin-bottom: var(--spacing-md);
}

.article-body pre code {
    background: none;
    padding: 0;
    color: inherit;
}

/* ==========================================
   Loading State
   ========================================== */
.loading {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-light);
    font-size: 1.125rem;
}

.loading i {
    margin-right: var(--spacing-xs);
}

/* ==========================================
   Empty State
   ========================================== */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-light);
}

.empty-state i {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.empty-state p {
    font-size: 1.125rem;
}

/* ==========================================
   Animations
   ========================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideUp {
    from {
        transform: translateY(30px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg-white);
        width: 100%;
        text-align: center;
        transition: left 0.3s ease;
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-md) 0;
        gap: var(--spacing-sm);
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: block;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-actions {
        flex-direction: column;
    }

    .section-title {
        font-size: 2rem;
    }

    .blog-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .blog-filters {
        width: 100%;
    }

    .search-box input {
        width: 100%;
    }

    .blog-grid {
        grid-template-columns: 1fr;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .modal-content {
        margin: 5% var(--spacing-sm);
        max-width: 100%;
    }

    .article-detail {
        padding: var(--spacing-md);
    }

    .article-title {
        font-size: 1.75rem;
    }

    .article-body {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .categories-grid {
        grid-template-columns: 1fr;
    }

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