/* === Reset & Base === */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #f59e0b;
    --text: #1f2937;
    --text-light: #6b7280;
    --bg: #ffffff;
    --bg-light: #f9fafb;
    --border: #e5e7eb;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-lg: 0 4px 6px rgba(0,0,0,0.1);
    --radius: 8px;
    --max-width: 1200px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
}

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

a:hover {
    color: var(--primary-dark);
}

img {
    max-width: 100%;
    height: auto;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1rem;
}

/* === Header === */
.site-header {
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
}

.logo:hover {
    color: var(--primary);
}

.logo-icon {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.nav-menu a {
    color: var(--text);
    font-weight: 500;
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
}

.nav-menu a:hover {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* === Main Content === */
.main-content {
    min-height: 70vh;
}

/* === Hero Section === */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* === Sections === */
section {
    padding: 3rem 0;
}

section h2 {
    font-size: 1.8rem;
    margin-bottom: 2rem;
    text-align: center;
}

/* === Article Grid === */
.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.article-card {
    background: var(--bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
}

.article-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.article-link {
    display: block;
    color: var(--text);
}

.article-link:hover {
    color: var(--text);
}

.article-image {
    height: 160px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.category-badge {
    background: var(--secondary);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.article-content {
    padding: 1rem;
}

.article-content h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.article-excerpt {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.article-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.8rem;
    color: var(--text-light);
}

/* === Category Grid === */
.categories-section {
    background: var(--bg-light);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 1.5rem;
}

.category-card {
    background: var(--bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow);
    transition: transform 0.2s;
    color: var(--text);
}

.category-card:hover {
    transform: translateY(-4px);
    color: var(--primary);
}

.category-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 0.5rem;
}

.category-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.category-card p {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.article-count {
    font-size: 0.8rem;
    color: var(--primary);
    font-weight: 600;
}

/* === List Articles === */
.article-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.list-article {
    background: var(--bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: box-shadow 0.2s;
}

.list-article:hover {
    box-shadow: var(--shadow-lg);
}

.list-article-link {
    display: block;
    color: var(--text);
}

.list-article-link:hover {
    color: var(--text);
}

.list-category {
    display: inline-block;
    background: var(--bg-light);
    color: var(--primary);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.list-article-content h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.list-article-content p {
    color: var(--text-light);
    margin-bottom: 0.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* === Single Article === */
.single-article {
    padding: 2rem 0;
}

.breadcrumb {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.breadcrumb a {
    color: var(--text-light);
}

.breadcrumb a:hover {
    color: var(--primary);
}

.article-header {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.article-header .category-badge {
    margin-bottom: 1rem;
    display: inline-block;
}

.article-header h1 {
    font-size: 2rem;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.article-body {
    font-size: 1.1rem;
    line-height: 1.8;
    max-width: 800px;
}

.article-body h2 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
    text-align: left;
}

.article-body h3 {
    font-size: 1.3rem;
    margin: 1.5rem 0 1rem;
}

.article-body p {
    margin-bottom: 1rem;
}

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

.article-body li {
    margin-bottom: 0.5rem;
}

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

.article-body code {
    background: var(--bg-light);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
}

.article-body pre {
    background: var(--bg-light);
    padding: 1rem;
    border-radius: var(--radius);
    overflow-x: auto;
    margin-bottom: 1rem;
}

.article-body img {
    border-radius: var(--radius);
    margin: 1rem 0;
}

.article-footer {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
    max-width: 800px;
}

.tags {
    margin-bottom: 1rem;
}

.tag-label {
    font-weight: 600;
    margin-right: 0.5rem;
}

.tag {
    display: inline-block;
    background: var(--bg-light);
    color: var(--text-light);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
}

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

.share-buttons {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.share-btn {
    background: var(--bg-light);
    border: 1px solid var(--border);
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

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

/* === Related Articles === */
.related-articles {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

.related-articles h2 {
    text-align: left;
    font-size: 1.5rem;
}

/* === Newsletter === */
.newsletter {
    background: var(--bg-light);
    text-align: center;
}

.newsletter h2 {
    margin-bottom: 0.5rem;
}

.newsletter p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.subscribe-form {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    max-width: 500px;
    margin: 0 auto;
}

.subscribe-form input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 1rem;
}

.subscribe-form button {
    padding: 0.75rem 1.5rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.2s;
}

.subscribe-form button:hover {
    background: var(--primary-dark);
}

/* === Pagination === */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    margin-top: 2rem;
}

.page-link {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    transition: all 0.2s;
}

.page-link:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.page-link.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* === Ad Placeholders === */
.sidebar-ad {
    position: fixed;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    width: 160px;
    display: none;
}

.inline-ad {
    padding: 2rem 0;
}

.ad-placeholder {
    background: var(--bg-light);
    border: 2px dashed var(--border);
    padding: 2rem;
    text-align: center;
    border-radius: var(--radius);
    color: var(--text-light);
}

/* === Footer === */
.site-footer {
    background: var(--text);
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 3rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-about h3, .footer-links h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: white;
}

.footer-about p {
    color: #9ca3af;
    font-size: 0.9rem;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a {
    color: #9ca3af;
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1rem;
    text-align: center;
    color: #6b7280;
    font-size: 0.85rem;
}

/* === Mobile Responsive === */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg);
        flex-direction: column;
        padding: 1rem;
        border-top: 1px solid var(--border);
        box-shadow: var(--shadow-lg);
    }

    .nav-menu.active {
        display: flex;
    }

    .hero h1 {
        font-size: 1.8rem;
    }

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

    .article-header h1 {
        font-size: 1.5rem;
    }

    .subscribe-form {
        flex-direction: column;
    }

    .sidebar-ad {
        display: none !important;
    }
}

@media (min-width: 1400px) {
    .sidebar-ad {
        display: block;
    }
}