/* ============================================
   CSS Variables - Theme System
   ============================================ */

:root {
    /* Dark Theme (Default) */
    --bg-primary: #0a0e27;
    --bg-secondary: #14192e;
    --bg-card: #1a1f3a;
    --text-primary: #f5f5f5;
    --text-secondary: #b8b8b8;
    --text-muted: #888888;
    --accent-primary: #00d4ff;
    --accent-secondary: #0066cc;
    --accent-highlight: #ffb020;
    --border-color: #2a2f4a;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-glow: rgba(0, 212, 255, 0.2);
}

[data-theme="light"] {
    /* Light Theme */
    --bg-primary: #fafafa;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --text-primary: #1a1f3a;
    --text-secondary: #4a4a4a;
    --text-muted: #6a6a6a;
    --accent-primary: #0066cc;
    --accent-secondary: #004499;
    --accent-highlight: #ff8800;
    --border-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --shadow-glow: rgba(0, 102, 204, 0.15);
}

/* ============================================
   Base Styles
   ============================================ */

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-mono);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
    overflow-x: hidden;
}

/* Subtle background pattern */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(90deg, transparent 0%, var(--border-color) 1px, transparent 1px),
        linear-gradient(0deg, transparent 0%, var(--border-color) 1px, transparent 1px);
    background-size: 50px 50px;
    opacity: 0.1;
    pointer-events: none;
    z-index: 0;
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-mono);
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.3s ease, opacity 0.3s ease;
}

a:hover {
    color: var(--accent-highlight);
    opacity: 0.9;
}

a:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* ============================================
   Layout Utilities
   ============================================ */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section {
    padding: 4rem 0;
    position: relative;
    z-index: 1;
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
    font-size: 2rem;
    position: relative;
    display: inline-block;
    width: 100%;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--accent-primary);
}

/* ============================================
   Header & Navigation
   ============================================ */

.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
    text-transform: uppercase;
    letter-spacing: 2px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 1px;
    position: relative;
    padding: 0.5rem 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-primary);
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link:focus::after,
.nav-link.active::after {
    width: 100%;
}

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

.menu-toggle {
    display: none;
    flex-direction: column;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    gap: 4px;
}

.menu-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all 0.3s ease;
}

.menu-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.menu-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ============================================
   Hero Section
   ============================================ */

.hero {
    min-height: 70vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 6rem 1.5rem;
    position: relative;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-content {
    max-width: 800px;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-highlight) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 0.8s ease;
}

.hero-tagline {
    font-size: 1.5rem;
    color: var(--accent-primary);
    margin-bottom: 1.5rem;
    font-weight: 500;
    letter-spacing: 2px;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    max-width: 600px;
    margin: 0 auto;
    animation: fadeInUp 0.8s ease 0.4s both;
}

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

/* ============================================
   Latest Article Section
   ============================================ */

.latest-article-section {
    background-color: var(--bg-primary);
}

.latest-article-container {
    max-width: 900px;
    margin: 0 auto;
}

.latest-article-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
}

.latest-article-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px var(--shadow-glow);
    border-color: var(--accent-primary);
}

.latest-article-image {
    width: 100%;
    height: 100%;
    min-height: 300px;
    overflow: hidden;
    background-color: var(--bg-secondary);
}

.latest-article-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.latest-article-card:hover .latest-article-image img {
    transform: scale(1.05);
}

.latest-article-content {
    padding: 2.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.latest-article-date {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.latest-article-title {
    margin-bottom: 1rem;
}

.latest-article-title a {
    color: var(--text-primary);
    font-size: 1.75rem;
    line-height: 1.3;
}

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

.latest-article-excerpt {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.latest-article-link {
    display: inline-block;
    color: var(--accent-primary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.latest-article-link:hover {
    color: var(--accent-highlight);
}

/* ============================================
   Blog Section
   ============================================ */

.blog-section {
    background-color: var(--bg-secondary);
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.blog-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    display: flex;
    flex-direction: column;
}

.blog-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px var(--shadow-glow);
    border-color: var(--accent-primary);
}

.blog-card-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background-color: var(--bg-secondary);
}

.blog-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease, opacity 0.3s ease;
    opacity: 0.9;
}

.blog-card-image img.loaded {
    opacity: 1;
}

.blog-card:hover .blog-card-image img {
    transform: scale(1.05);
}

.blog-card-content {
    padding: 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.blog-card-date {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.blog-card-title {
    margin-bottom: 0.75rem;
}

.blog-card-title a {
    color: var(--text-primary);
    font-size: 1.25rem;
}

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

.blog-card-excerpt {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    flex-grow: 1;
}

/* Loading Spinner */
.loading-spinner {
    text-align: center;
    padding: 3rem;
    color: var(--text-muted);
    font-size: 1rem;
}

.loading-spinner::after {
    content: '...';
    animation: dots 1.5s steps(4, end) infinite;
}

@keyframes dots {
    0%, 20% { content: '.'; }
    40% { content: '..'; }
    60%, 100% { content: '...'; }
}

/* Button Styles */
.btn-primary {
    display: inline-block;
    padding: 0.75rem 2rem;
    background-color: var(--bg-card);
    border: 1px solid var(--accent-primary);
    border-radius: 8px;
    color: var(--accent-primary);
    font-family: var(--font-mono);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    text-decoration: none;
}

.btn-primary:hover {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--shadow-glow);
}

/* ============================================
   Projects Section
   ============================================ */

.projects-section {
    background-color: var(--bg-primary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.project-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px var(--shadow-glow);
    border-color: var(--accent-primary);
}

.project-card-title {
    color: var(--accent-primary);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.project-card-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.project-card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--accent-primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* ============================================
   About Section
   ============================================ */

.about-section {
    background-color: var(--bg-secondary);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
}

.interests {
    margin-top: 3rem;
    text-align: left;
    display: inline-block;
}

.interests h3 {
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--accent-primary);
}

.interests ul {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.75rem;
}

.interests li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.interests li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: bold;
}

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

.footer {
    background-color: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1.5rem;
    margin-top: 4rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-section {
    flex: 1;
    min-width: 200px;
}

.footer-title {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--accent-primary);
}

.social-links {
    list-style: none;
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.social-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.theme-toggle {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem 1.5rem;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theme-toggle:hover {
    background-color: var(--bg-secondary);
    border-color: var(--accent-primary);
    transform: scale(1.05);
}

.theme-toggle-icon {
    font-size: 1.2rem;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

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

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .menu-toggle {
        display: flex;
    }

    .latest-article-card {
        grid-template-columns: 1fr;
    }

    .latest-article-image {
        min-height: 200px;
    }

    .latest-article-content {
        padding: 1.5rem;
    }

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

    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background-color: var(--bg-secondary);
        flex-direction: column;
        padding: 2rem;
        border-top: 1px solid var(--border-color);
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        z-index: 999;
    }

    .nav-menu.active {
        transform: translateX(0);
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-tagline {
        font-size: 1.25rem;
    }

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

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

    .section {
        padding: 3rem 0;
    }

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

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

    .interests ul {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero {
        min-height: 60vh;
        padding: 4rem 1rem;
    }

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

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

    .container {
        padding: 0 1rem;
    }

    .blog-card-content,
    .project-card {
        padding: 1.25rem;
    }
}

/* ============================================
   Print Styles
   ============================================ */

@media print {
    .header,
    .footer,
    .menu-toggle,
    .theme-toggle {
        display: none;
    }

    body {
        background: white;
        color: black;
    }

    .section {
        page-break-inside: avoid;
    }
}