/* ===================================
   CSS Variables & Design System
   =================================== */
:root {
    /* Colors */
    --color-primary: #0a0e27;
    --color-secondary: #1e293b;
    --color-accent: #22d3ee;
    --color-text: #e2e8f0;
    --color-muted: #64748b;
    --color-code-bg: #0f172a;
    --color-border: rgba(34, 211, 238, 0.1);
    --color-card-bg: rgba(30, 41, 59, 0.5);
    
    /* Typography */
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.6s ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 20px rgba(34, 211, 238, 0.2);
}

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

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

body {
    font-family: var(--font-sans);
    background-color: var(--color-primary);
    color: var(--color-text);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

::selection {
    background-color: var(--color-accent);
    color: var(--color-primary);
}

/* ===================================
   Typography
   =================================== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-mono);
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: all var(--transition-base);
}

a:hover {
    color: var(--color-text);
}

/* ===================================
   Navigation
   =================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: var(--spacing-sm) 0;
    background-color: transparent;
    transition: all var(--transition-base);
}

.nav.scrolled {
    background-color: rgba(10, 14, 39, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.cursor-blink {
    color: var(--color-accent);
    animation: blink 1s infinite;
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

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

.nav-link {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-muted);
    position: relative;
    padding: 0.5rem 0;
}

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

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

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

/* ===================================
   Hero Section
   =================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-xl) var(--spacing-md);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

#particles-canvas {
    width: 100%;
    height: 100%;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 1000px;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--color-muted);
    line-height: 1.8;
    animation: fadeInUp 1s ease 0.2s backwards;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-muted);
    animation: fadeInUp 1s ease 0.4s backwards;
}

.scroll-text {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.scroll-arrow {
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

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

/* ===================================
   Section Styles
   =================================== */
.section {
    padding: var(--spacing-xl) var(--spacing-md);
    position: relative;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--spacing-lg);
    color: var(--color-text);
    position: relative;
    display: inline-block;
}

.section-title::before {
    content: '//';
    color: var(--color-accent);
    margin-right: var(--spacing-xs);
}

/* ===================================
   Focus Section
   =================================== */
.focus-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-md);
}

.focus-card {
    background: var(--color-card-bg);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: var(--spacing-md);
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
}

.focus-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-glow);
    border-color: var(--color-accent);
}

.card-icon {
    width: 48px;
    height: 48px;
    margin-bottom: var(--spacing-sm);
    color: var(--color-accent);
    transition: all var(--transition-base);
}

.focus-card:hover .card-icon {
    transform: scale(1.1);
}

.card-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.card-description {
    color: var(--color-muted);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.card-list {
    margin-top: var(--spacing-md);
}

.list-label {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
}

.card-list ul {
    list-style: none;
    padding-left: 0;
}

.card-list li {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-muted);
    padding: 0.375rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.card-list li::before {
    content: '•';
    position: absolute;
    left: 0.5rem;
    color: var(--color-accent);
}

/* ===================================
   Background Section
   =================================== */
.background-section {
    background: linear-gradient(180deg, var(--color-primary) 0%, var(--color-secondary) 100%);
}

.background-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: start;
}

.background-intro {
    font-size: 1.25rem;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.background-block {
    margin-bottom: var(--spacing-md);
}

.background-subtitle {
    font-size: 1.125rem;
    color: var(--color-accent);
    margin-bottom: var(--spacing-sm);
}

.expertise-list {
    list-style: none;
    padding-left: 0;
}

.expertise-list li {
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    color: var(--color-muted);
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.expertise-list li::before {
    content: '•';
    position: absolute;
    left: 0.5rem;
    color: var(--color-accent);
}

.background-visual {
    position: sticky;
    top: 120px;
}

.tech-stack {
    background: var(--color-card-bg);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: var(--spacing-md);
    backdrop-filter: blur(10px);
}

.tech-item {
    margin-bottom: var(--spacing-md);
}

.tech-item:last-child {
    margin-bottom: 0;
}

.tech-label {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-text);
    display: block;
    margin-bottom: var(--spacing-xs);
}

.tech-bar {
    height: 8px;
    background: var(--color-code-bg);
    border-radius: 4px;
    position: relative;
    overflow: hidden;
}

.tech-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: var(--width);
    background: linear-gradient(90deg, var(--color-accent) 0%, #06b6d4 100%);
    border-radius: 4px;
    animation: fillBar 1.5s ease;
}

@keyframes fillBar {
    from { width: 0; }
}

/* ===================================
   Notes Section
   =================================== */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.note-card {
    background: var(--color-card-bg);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: var(--spacing-md);
    transition: all var(--transition-base);
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
}

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

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

.note-tag {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-accent);
    background: rgba(34, 211, 238, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.note-date {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-muted);
}

.note-title {
    font-size: 1.25rem;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.note-preview {
    color: var(--color-muted);
    line-height: 1.7;
    margin-bottom: var(--spacing-sm);
    flex-grow: 1;
}

.note-link {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-accent);
    align-self: flex-start;
}

.note-link:hover {
    transform: translateX(4px);
}

.notes-footer {
    text-align: center;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-muted);
    font-style: italic;
}

/* ===================================
   Connect Section
   =================================== */
.connect-section {
    background: linear-gradient(180deg, var(--color-primary) 0%, var(--color-secondary) 100%);
}

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

.connect-intro {
    font-size: 1.25rem;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.connect-text {
    color: var(--color-muted);
    margin-bottom: var(--spacing-md);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin: var(--spacing-lg) 0;
}

.contact-item {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--color-card-bg);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: all var(--transition-base);
}

.contact-item:hover {
    border-color: var(--color-accent);
    box-shadow: var(--shadow-sm);
}

.contact-icon {
    color: var(--color-accent);
    flex-shrink: 0;
}

.contact-link {
    font-family: var(--font-mono);
    font-size: 1.125rem;
    color: var(--color-text);
}

.contact-text {
    font-family: var(--font-mono);
    color: var(--color-muted);
}

.contact-address {
    text-align: left;
}

.contact-address p {
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    color: var(--color-muted);
    line-height: 1.6;
}

.connect-status {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-muted);
    font-style: italic;
    margin-top: var(--spacing-md);
}

/* ===================================
   Footer
   =================================== */
.footer {
    padding: var(--spacing-lg) var(--spacing-md);
    text-align: center;
    border-top: 1px solid var(--color-border);
}

.footer-text {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-muted);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    .background-grid {
        grid-template-columns: 1fr;
    }
    
    .background-visual {
        position: static;
    }
}

@media (max-width: 768px) {
    :root {
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }
    
    .nav-links {
        gap: var(--spacing-sm);
    }
    
    .nav-link {
        font-size: 0.75rem;
    }
    
    .focus-grid,
    .notes-grid {
        grid-template-columns: 1fr;
    }
    
    .hero {
        padding: var(--spacing-lg) var(--spacing-sm);
    }
    
    .section {
        padding: var(--spacing-lg) var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 0 var(--spacing-sm);
    }
    
    .nav-logo {
        font-size: 1rem;
    }
    
    .nav-links {
        display: none;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 0.9375rem;
    }
}

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

.focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 4px;
}

/* ===================================
   Utility Classes
   =================================== */
.fade-in {
    animation: fadeInUp 0.8s ease;
}

.slide-in-left {
    animation: slideInLeft 0.8s ease;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}