/* ============================================
   CSS Custom Properties (Theming)
   ============================================ */

:root {
    /* Light theme colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-primary: #1a1a1a;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    --border-color: #e5e7eb;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --card-bg: #ffffff;
    --nav-bg: rgba(255, 255, 255, 0.95);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-base: 1rem;
    --font-size-sm: 0.875rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 3rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Geometric shapes */
    --shape-size: 200px;
    --shape-opacity: 0.05;
}

[data-theme="dark"] {
    --bg-primary: #0a0a0a;
    --bg-secondary: #141414;
    --text-primary: #f5f5f5;
    --text-secondary: #a3a3a3;
    --text-muted: #737373;
    --border-color: #262626;
    --accent-color: #60a5fa;
    --accent-hover: #3b82f6;
    --card-bg: #141414;
    --nav-bg: rgba(10, 10, 10, 0.95);
    --shape-opacity: 0.1;
}

/* ============================================
   Reset & Base Styles
   ============================================ */

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

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

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

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: color var(--transition-fast);
    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: var(--accent-color);
    border-radius: 2px;
}

.theme-toggle {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: 1.1rem;
}

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

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

.main {
    min-height: calc(100vh - 200px);
}

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

.hero {
    position: relative;
    padding: var(--spacing-2xl) var(--spacing-md);
    min-height: 70vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-content {
    max-width: 800px;
    text-align: center;
    position: relative;
    z-index: 1;
    animation: fadeInUp 0.8s ease-out;
}

.hero-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.title-line {
    display: block;
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    font-weight: 300;
}

.hero-links {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.social-links {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-lg);
    font-size: var(--font-size-lg);
}

.social-link {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-base);
    font-weight: 400;
}

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

.social-separator {
    color: var(--text-muted);
    margin: 0 var(--spacing-xs);
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    text-decoration: none;
    border-radius: 6px;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
    transform: translateY(-2px);
}

/* ============================================
   Geometric Shapes
   ============================================ */

.geometric-shape {
    position: absolute;
    opacity: var(--shape-opacity);
    pointer-events: none;
    z-index: 0;
    transition: opacity var(--transition-base);
}

.shape-circle {
    width: var(--shape-size);
    height: var(--shape-size);
    border-radius: 50%;
    border: 2px solid var(--accent-color);
    animation: float 20s ease-in-out infinite;
}

.shape-triangle {
    width: 0;
    height: 0;
    border-left: 100px solid transparent;
    border-right: 100px solid transparent;
    border-bottom: 173px solid var(--accent-color);
    animation: float 15s ease-in-out infinite reverse;
}

.hero .geometric-shape.shape-circle {
    top: 10%;
    left: 10%;
}

.hero .geometric-shape.shape-triangle {
    bottom: 20%;
    right: 15%;
}

.page-header .geometric-shape.shape-circle {
    top: -50px;
    right: 10%;
}

.page-header .geometric-shape.shape-triangle {
    top: 50px;
    left: 5%;
}

/* ============================================
   Animations
   ============================================ */

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

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) rotate(0deg);
    }
    33% {
        transform: translate(30px, -30px) rotate(5deg);
    }
    66% {
        transform: translate(-20px, 20px) rotate(-5deg);
    }
}

/* ============================================
   Page Header
   ============================================ */

.page-header {
    position: relative;
    padding: var(--spacing-2xl) var(--spacing-md);
    text-align: center;
    overflow: hidden;
}

.page-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    position: relative;
    z-index: 1;
}

.page-subtitle {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    font-weight: 300;
    position: relative;
    z-index: 1;
}

/* ============================================
   Content Sections
   ============================================ */

.content-section {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-xl);
    color: var(--text-primary);
    text-align: center;
}

/* ============================================
   Featured Section
   ============================================ */

.featured {
    padding: var(--spacing-2xl) 0;
    background-color: var(--bg-secondary);
    transition: background-color var(--transition-base);
}

.featured-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.featured-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.featured-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--accent-color);
    transform: scaleY(0);
    transition: transform var(--transition-base);
}

.featured-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    border-color: var(--accent-color);
}

.featured-card:hover::before {
    transform: scaleY(1);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    font-size: var(--font-size-sm);
}

.card-category {
    color: var(--accent-color);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.card-date {
    color: var(--text-muted);
}

.card-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.card-excerpt {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.card-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--font-size-sm);
    transition: all var(--transition-fast);
    display: inline-block;
}

.card-link:hover {
    color: var(--accent-hover);
    transform: translateX(4px);
}

/* ============================================
   Posts Grid
   ============================================ */

.posts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.post-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
    animation: fadeInUp 0.6s ease-out;
    animation-fill-mode: both;
}

.post-card:nth-child(1) { animation-delay: 0.1s; }
.post-card:nth-child(2) { animation-delay: 0.2s; }
.post-card:nth-child(3) { animation-delay: 0.3s; }
.post-card:nth-child(4) { animation-delay: 0.4s; }

.post-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    border-color: var(--accent-color);
}

.post-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.post-excerpt {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.card-tag {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: 20px;
    font-size: var(--font-size-sm);
    font-weight: 500;
}

/* ============================================
   Projects Grid
   ============================================ */

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

.project-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
    animation: fadeInUp 0.6s ease-out;
    animation-fill-mode: both;
    display: flex;
    flex-direction: column;
}

.project-card:nth-child(1) { animation-delay: 0.1s; }
.project-card:nth-child(2) { animation-delay: 0.2s; }
.project-card:nth-child(3) { animation-delay: 0.3s; }
.project-card:nth-child(4) { animation-delay: 0.4s; }

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    border-color: var(--accent-color);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
}

.project-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.project-status {
    font-size: var(--font-size-sm);
    padding: 4px 12px;
    border-radius: 20px;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    font-weight: 500;
    white-space: nowrap;
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
    flex-grow: 1;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.tag {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: 20px;
    font-size: var(--font-size-sm);
    font-weight: 500;
    border: 1px solid var(--border-color);
}

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

.project-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--font-size-sm);
    transition: all var(--transition-fast);
}

.project-link:hover {
    color: var(--accent-hover);
    transform: translateX(4px);
}

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

.footer {
    padding: var(--spacing-xl) 0;
    border-top: 1px solid var(--border-color);
    margin-top: var(--spacing-2xl);
    text-align: center;
    color: var(--text-muted);
    font-size: var(--font-size-sm);
    transition: border-color var(--transition-base), color var(--transition-base);
}

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

@media (max-width: 768px) {
    :root {
        --font-size-4xl: 2rem;
        --font-size-3xl: 1.75rem;
        --spacing-2xl: 2rem;
        --shape-size: 150px;
    }

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

    .nav-links {
        gap: var(--spacing-sm);
        flex-wrap: wrap;
    }

    .hero-title {
        font-size: var(--font-size-3xl);
    }

    .hero-subtitle {
        font-size: var(--font-size-lg);
    }

    .hero-links {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

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

    .geometric-shape {
        display: none;
    }

    .page-title {
        font-size: var(--font-size-3xl);
    }

    .project-header {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
}

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

    .nav-container {
        padding: var(--spacing-sm);
    }

    .hero,
    .page-header {
        padding: var(--spacing-xl) var(--spacing-sm);
    }

    .content-section {
        padding: var(--spacing-xl) 0;
    }

    .featured-card,
    .post-card,
    .project-card {
        padding: var(--spacing-md);
    }
}

/* ============================================
   Accessibility
   ============================================ */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}