/* CSS Variables */
:root {
    /* Light theme (default) */
    --bg-primary: #ffffff;
    --bg-secondary: #f7f7f8;
    --bg-tertiary: #ececf1;
    --text-primary: #0d0d0d;
    --text-secondary: #4a4a4a;
    --text-tertiary: #6e6e80;
    --border-color: #e5e5e5;
    --accent-primary: #10a37f;
    --accent-secondary: #1a7f64;
    --accent-gradient: linear-gradient(135deg, #10a37f 0%, #0d8c6d 100%);
    --card-bg: #ffffff;
    --card-hover: #f9f9f9;
    --code-bg: #f4f4f4;
    --shadow-sm: 0 1px 2px 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);
    --modal-bg: rgba(255, 255, 255, 0.95);
}

[data-theme="dark"] {
    --bg-primary: #0d0d0d;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #2d2d2d;
    --text-primary: #ececf1;
    --text-secondary: #b4b4b4;
    --text-tertiary: #8e8ea0;
    --border-color: #2d2d2d;
    --accent-primary: #10a37f;
    --accent-secondary: #19c99a;
    --card-bg: #1a1a1a;
    --card-hover: #242424;
    --code-bg: #1e1e1e;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --modal-bg: rgba(13, 13, 13, 0.95);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

ul {
    list-style: none;
}

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: color 0.2s ease;
}

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

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

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

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-link {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.2s ease;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--accent-primary);
    border-radius: 1px;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.search-btn,
.theme-toggle {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    color: var(--text-secondary);
    transition: background-color 0.2s ease, color 0.2s ease;
}

.search-btn:hover,
.theme-toggle:hover {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.theme-toggle .sun-icon {
    display: none;
}

.theme-toggle .moon-icon {
    display: block;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: block;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: none;
}

.btn-subscribe {
    padding: 8px 16px;
    background: var(--accent-gradient);
    color: white;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 6px;
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.btn-subscribe:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 24px;
    padding: 4px 0;
}

.mobile-menu-btn span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: 1px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Menu */
.mobile-menu {
    display: none;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 16px 24px;
    flex-direction: column;
    gap: 16px;
    z-index: 999;
}

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

.mobile-menu .nav-link {
    font-size: 1rem;
    padding: 8px 0;
}

.mobile-menu .btn-subscribe {
    text-align: center;
    margin-top: 8px;
}

/* Hero Section */
.hero {
    padding: 140px 0 60px;
    background-color: var(--bg-primary);
}

.hero-content {
    max-width: 720px;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 560px;
}

/* Categories */
.categories {
    padding: 24px 0;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 64px;
    z-index: 100;
}

.category-tabs {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 4px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
}

.category-tabs::-webkit-scrollbar {
    display: none;
}

.category-tab {
    padding: 8px 16px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    background-color: transparent;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    white-space: nowrap;
    transition: all 0.2s ease;
}

.category-tab:hover {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.category-tab.active {
    background-color: var(--text-primary);
    color: var(--bg-primary);
    border-color: var(--text-primary);
}

/* Featured Post */
.featured {
    padding: 48px 0;
}

.featured-post {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 32px;
    transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.featured-post:hover {
    box-shadow: var(--shadow-lg);
}

.featured-image {
    aspect-ratio: 16 / 10;
    border-radius: 12px;
    overflow: hidden;
}

.image-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-primary);
}

.image-placeholder.small {
    aspect-ratio: 16 / 10;
    border-radius: 8px;
}

.post-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.post-category {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent-primary);
    padding: 4px 10px;
    background-color: rgba(16, 163, 127, 0.1);
    border-radius: 4px;
}

.post-date {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.featured-title {
    font-size: 1.75rem;
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 16px;
}

.featured-title a {
    transition: color 0.2s ease;
}

.featured-title a:hover {
    color: var(--accent-primary);
}

.featured-excerpt {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 24px;
}

.post-author {
    display: flex;
    align-items: center;
    gap: 12px;
}

.author-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--accent-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 0.875rem;
    font-weight: 600;
}

.author-info {
    display: flex;
    flex-direction: column;
}

.author-name {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.read-time {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
}

/* Blog Posts Grid */
.blog-section {
    padding: 48px 0 80px;
}

.posts-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.post-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.post-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-primary);
}

.post-card-image {
    padding: 20px 20px 0;
}

.post-card-content {
    padding: 20px;
}

.post-card-title {
    font-size: 1.125rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: 12px;
}

.post-card-title a {
    transition: color 0.2s ease;
}

.post-card-title a:hover {
    color: var(--accent-primary);
}

.post-card-excerpt {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.post-card .read-time {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
}

/* Load More */
.load-more {
    text-align: center;
    margin-top: 48px;
}

.btn-load-more {
    padding: 12px 32px;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.2s ease;
}

.btn-load-more:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--text-tertiary);
}

/* Newsletter */
.newsletter {
    padding: 80px 0;
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.newsletter-content {
    max-width: 560px;
    margin: 0 auto;
    text-align: center;
}

.newsletter-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.newsletter-text {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.newsletter-form {
    display: flex;
    gap: 12px;
    max-width: 440px;
    margin: 0 auto;
}

.newsletter-form input {
    flex: 1;
    padding: 14px 16px;
    font-size: 1rem;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    transition: border-color 0.2s ease;
}

.newsletter-form input::placeholder {
    color: var(--text-tertiary);
}

.newsletter-form input:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.newsletter-form button {
    padding: 14px 24px;
    font-size: 1rem;
    font-weight: 500;
    color: white;
    background: var(--accent-gradient);
    border-radius: 8px;
    transition: opacity 0.2s ease;
}

.newsletter-form button:hover {
    opacity: 0.9;
}

.newsletter-disclaimer {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    margin-top: 12px;
}

/* Footer */
.footer {
    padding: 64px 0 32px;
    background-color: var(--bg-primary);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 64px;
    margin-bottom: 48px;
}

.footer-brand .logo {
    display: inline-block;
    margin-bottom: 16px;
}

.footer-tagline {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
    max-width: 280px;
}

.social-links {
    display: flex;
    gap: 16px;
}

.social-links a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    color: var(--text-secondary);
    background-color: var(--bg-secondary);
    transition: all 0.2s ease;
}

.social-links a:hover {
    color: var(--accent-primary);
    background-color: var(--bg-tertiary);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.footer-column h4 {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.footer-column ul li {
    margin-bottom: 12px;
}

.footer-column ul li a {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    transition: color 0.2s ease;
}

.footer-column ul li a:hover {
    color: var(--accent-primary);
}

.footer-bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 32px;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.footer-legal {
    display: flex;
    gap: 24px;
}

.footer-legal a {
    font-size: 0.875rem;
    color: var(--text-tertiary);
    transition: color 0.2s ease;
}

.footer-legal a:hover {
    color: var(--text-secondary);
}

/* Search Modal */
.search-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--modal-bg);
    backdrop-filter: blur(8px);
    z-index: 2000;
    padding: 120px 24px 24px;
}

.search-modal.active {
    display: block;
}

.search-modal-content {
    max-width: 640px;
    margin: 0 auto;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.search-input-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
}

.search-input-wrapper svg {
    color: var(--text-tertiary);
    flex-shrink: 0;
}

.search-input-wrapper input {
    flex: 1;
    border: none;
    background: none;
    font-size: 1rem;
    color: var(--text-primary);
    outline: none;
}

.search-input-wrapper input::placeholder {
    color: var(--text-tertiary);
}

.search-input-wrapper kbd {
    padding: 4px 8px;
    font-size: 0.75rem;
    font-family: 'JetBrains Mono', monospace;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-tertiary);
}

.search-results {
    padding: 20px;
    max-height: 400px;
    overflow-y: auto;
}

.search-hint {
    font-size: 0.9375rem;
    color: var(--text-tertiary);
    text-align: center;
}

.search-result-item {
    padding: 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.search-result-item:hover {
    background-color: var(--bg-secondary);
}

.search-result-item h4 {
    font-size: 0.9375rem;
    font-weight: 500;
    margin-bottom: 4px;
}

.search-result-item p {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.post-card {
    animation: fadeIn 0.4s ease forwards;
}

.post-card:nth-child(1) { animation-delay: 0.1s; }
.post-card:nth-child(2) { animation-delay: 0.15s; }
.post-card:nth-child(3) { animation-delay: 0.2s; }
.post-card:nth-child(4) { animation-delay: 0.25s; }
.post-card:nth-child(5) { animation-delay: 0.3s; }
.post-card:nth-child(6) { animation-delay: 0.35s; }

/* Responsive */
@media (max-width: 1024px) {
    .posts-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .featured-post {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 48px;
    }
}

@media (max-width: 768px) {
    .nav-links,
    .nav-actions .search-btn,
    .nav-actions .btn-subscribe {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero {
        padding: 100px 0 40px;
    }

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

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

    .categories {
        top: 64px;
    }

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

    .featured-post {
        padding: 20px;
    }

    .featured-title {
        font-size: 1.375rem;
    }

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

    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-bottom {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .footer-links {
        grid-template-columns: 1fr;
    }

    .social-links {
        justify-content: center;
    }

    .footer-brand {
        text-align: center;
    }

    .footer-tagline {
        max-width: 100%;
    }
}

/* Post visibility for filtering */
.post-card.hidden,
.featured-post.hidden {
    display: none;
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

/* Selection styling */
::selection {
    background-color: var(--accent-primary);
    color: white;
}