/* ==========================================
   CSS VARIABLES & DESIGN TOKENS
   ========================================== */

:root {
    /* --- Core Brand Colors (VS Code Inspired) --- */
    --primary-bg: #0d1117;          /* GitHub dark background */
    --secondary-bg: #161b22;        /* Card backgrounds */
    --tertiary-bg: #21262d;         /* Elevated surfaces */
    --accent-bg: #f0f6fc;           /* Light sections */
    
    /* --- Text Colors --- */
    --text-primary: #f0f6fc;        /* Primary white text */
    --text-secondary: #8b949e;      /* Muted text */
    --text-tertiary: #6e7681;       /* Subtle text */
    --text-dark: #24292f;           /* Dark text for light bg */
    
    /* --- Accent Colors (Syntax Highlighting Inspired) --- */
    --accent-cyan: #7dd3fc;         /* Function names */
    --accent-emerald: #34d399;      /* Strings */
    --accent-purple: #a78bfa;       /* Keywords */
    --accent-orange: #fb923c;       /* Constants */
    --accent-pink: #f472b6;         /* Operators */
    --accent-blue: #60a5fa;         /* Types */
    
    /* --- State Colors --- */
    --success: #238636;
    --warning: #f85149;
    --info: #0969da;
    
    /* --- Border & Effects --- */
    --border-subtle: #30363d;
    --border-muted: #21262d;
    --shadow-color: rgba(0, 0, 0, 0.5);
    --glow-cyan: rgba(125, 211, 252, 0.4);
    --glow-emerald: rgba(52, 211, 153, 0.4);
    
    /* --- Typography --- */
    --font-mono: 'Fira Code', 'JetBrains Mono', 'SF Mono', Monaco, 'Cascadia Code', monospace;
    --font-sans: 'Inter', 'SF Pro Display', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
    
    /* --- Spacing & Layout --- */
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ==========================================
   GLOBAL RESET & BASE STYLES
   ========================================== */

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-sans);
    line-height: 1.7;
    color: var(--text-primary);
    background: var(--primary-bg);
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

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

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

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-emerald);
}

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

/* ==========================================
   HEADER & NAVIGATION
   ========================================== */

header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(13, 17, 23, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 1000;
    padding: 1rem 0;
    transition: var(--transition-smooth);
    border-bottom: 1px solid var(--border-subtle);
}

header.scrolled {
    background: rgba(13, 17, 23, 0.98);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-cyan);
    font-family: var(--font-mono);
    text-decoration: none;
    position: relative;
}

.logo::before {
    content: '{ ';
    color: var(--accent-emerald);
    animation: pulse 2s ease-in-out infinite;
}

.logo::after {
    content: ' }';
    color: var(--accent-emerald);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2.5rem;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition-smooth);
    position: relative;
    padding: 0.5rem 0;
}

.nav-links a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-emerald));
    transition: width 0.3s ease;
}

.nav-links a:hover {
    color: var(--text-primary);
}

.nav-links a:hover::before {
    width: 100%;
}

/* Mobile Menu */
.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--accent-cyan);
    transition: var(--transition-smooth);
}

/* ==========================================
   HERO SECTION
   ========================================== */

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

/* Animated background grid */
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(rgba(125, 211, 252, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(125, 211, 252, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: grid-move 20s linear infinite;
    z-index: 1;
}

@keyframes grid-move {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
    padding: 2rem;
}

.hero-greeting {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    color: var(--accent-emerald);
    margin-bottom: 1rem;
    opacity: 0;
    animation: slideInDown 0.8s ease-out 0.2s forwards;
}

.hero h1 {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 800;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    opacity: 0;
    animation: slideInUp 0.8s ease-out 0.4s forwards;
}

.hero-subtitle {
    font-size: 1.4rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    font-family: var(--font-mono);
    opacity: 0;
    animation: slideInUp 0.8s ease-out 0.6s forwards;
}

.terminal-line {
    display: block;
    margin-bottom: 0.5rem;
}

.terminal-line::before {
    content: '$ ';
    color: var(--accent-emerald);
}

.cta-group {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    opacity: 0;
    animation: slideInUp 0.8s ease-out 0.8s forwards;
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    font-family: var(--font-mono);
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition-spring);
    position: relative;
    overflow: hidden;
}

.cta-button.primary {
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald));
    color: var(--primary-bg);
    box-shadow: 0 10px 30px rgba(125, 211, 252, 0.3);
}

.cta-button.secondary {
    background: transparent;
    color: var(--accent-cyan);
    border: 2px solid var(--accent-cyan);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 20px 40px rgba(125, 211, 252, 0.4);
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.cta-button:hover::before {
    left: 100%;
}

/* Floating code elements */
.floating-code {
    position: absolute;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--text-tertiary);
    opacity: 0.6;
    animation: float 6s ease-in-out infinite;
    z-index: 1;
    user-select: none;
    pointer-events: none;
}

.floating-code:nth-child(1) {
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.floating-code:nth-child(2) {
    top: 60%;
    right: 15%;
    animation-delay: 2s;
}

.floating-code:nth-child(3) {
    top: 80%;
    left: 20%;
    animation-delay: 4s;
}

.floating-code:nth-child(4) {
    top: 30%;
    right: 25%;
    animation-delay: 1s;
}

/* ==========================================
   SECTION LAYOUTS
   ========================================== */

.section {
    padding: 120px 0;
    position: relative;
}

.section:nth-child(even) {
    background: var(--accent-bg);
    color: var(--text-dark);
}

.section:nth-child(even) .section-title {
    color: var(--text-dark);
}

.section-header {
    text-align: center;
    margin-bottom: 5rem;
}

.section-tag {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--accent-cyan);
    margin-bottom: 1rem;
    opacity: 0;
    animation: fadeInUp 0.6s ease-out forwards;
}

.section-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    opacity: 0;
    animation: fadeInUp 0.6s ease-out 0.2s forwards;
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    opacity: 0;
    animation: fadeInUp 0.6s ease-out 0.4s forwards;
}

/* ==========================================
   ABOUT SECTION
   ========================================== */

.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 4rem;
    align-items: center;
    margin-top: 2rem;
}

.profile-container {
    position: relative;
    text-align: center;
}

.profile-pic {
    width: 280px;
    height: 280px;
    border-radius: var(--border-radius-lg);
    background: linear-gradient(135deg, var(--secondary-bg), var(--tertiary-bg));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 5rem;
    color: var(--accent-cyan);
    margin: 0 auto;
    position: relative;
    overflow: hidden;
    border: 3px solid var(--accent-cyan);
    box-shadow: 0 20px 60px rgba(125, 211, 252, 0.2);
    transition: var(--transition-spring);
}

.profile-pic::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, transparent, var(--glow-cyan), transparent);
    opacity: 0;
    transition: opacity 0.5s ease;
}

.profile-pic:hover {
    transform: scale(1.05) rotate(3deg);
    box-shadow: 0 30px 80px rgba(125, 211, 252, 0.4);
}

.profile-pic:hover::before {
    opacity: 0.3;
}

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

.about-text p {
    margin-bottom: 1.5rem;
}

.about-text strong {
    color: var(--accent-emerald);
    font-family: var(--font-mono);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
}

.stat-item {
    text-align: center;
    padding: 1.5rem;
    background: var(--secondary-bg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-subtle);
    transition: var(--transition-smooth);
}

.stat-item:hover {
    transform: translateY(-5px);
    border-color: var(--accent-cyan);
    box-shadow: 0 10px 30px rgba(125, 211, 252, 0.2);
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--accent-cyan);
    font-family: var(--font-mono);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-tertiary);
    margin-top: 0.5rem;
}

/* ==========================================
   EXPERIENCE TIMELINE
   ========================================== */

.experience-timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.experience-timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--accent-cyan), var(--accent-emerald));
    transform: translateX(-50%);
}

.timeline-item {
    display: flex;
    margin-bottom: 3rem;
    position: relative;
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
}

.timeline-marker {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-bg);
    font-size: 1.2rem;
    z-index: 2;
    box-shadow: 0 8px 25px var(--glow-cyan);
}

.timeline-content {
    background: var(--secondary-bg);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--border-subtle);
    width: calc(50% - 40px);
    transition: var(--transition-smooth);
}

.timeline-item:nth-child(odd) .timeline-content {
    margin-right: 80px;
}

.timeline-item:nth-child(even) .timeline-content {
    margin-left: 80px;
}

.timeline-content:hover {
    transform: translateY(-5px);
    border-color: var(--accent-cyan);
    box-shadow: 0 15px 40px rgba(125, 211, 252, 0.2);
}

.timeline-content h3 {
    color: var(--text-primary);
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.timeline-content h4 {
    color: var(--accent-cyan);
    font-size: 1rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.timeline-date {
    color: var(--text-tertiary);
    font-size: 0.9rem;
    font-family: var(--font-mono);
    margin-bottom: 1rem;
    display: block;
}

.timeline-content p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.timeline-skills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.timeline-skills span {
    background: var(--tertiary-bg);
    color: var(--accent-emerald);
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
    font-family: var(--font-mono);
}

/* ==========================================
   RESEARCH SECTION
   ========================================== */

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.research-category {
    background: var(--secondary-bg);
    padding: 2.5rem;
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--border-subtle);
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.research-category::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-emerald), var(--accent-purple));
}

.research-category:hover {
    transform: translateY(-8px);
    border-color: var(--accent-cyan);
    box-shadow: 0 20px 50px rgba(125, 211, 252, 0.2);
}

.research-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald));
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    font-size: 2rem;
    color: var(--primary-bg);
    box-shadow: 0 10px 30px var(--glow-cyan);
}

.research-category h3 {
    font-size: 1.4rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 700;
}

.research-category p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

/* ==========================================
   PROJECT METRICS
   ========================================== */

.project-metrics {
    display: flex;
    gap: 2rem;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--tertiary-bg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-subtle);
}

.metric {
    text-align: center;
}

.metric-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--accent-cyan);
    font-family: var(--font-mono);
}

.metric-label {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    margin-top: 0.2rem;
}

/* ==========================================
   PUBLICATIONS SECTION
   ========================================== */

.publications-grid {
    display: grid;
    gap: 2rem;
    margin-top: 3rem;
}

.publication-item {
    background: var(--secondary-bg);
    padding: 2.5rem;
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--border-subtle);
    transition: var(--transition-smooth);
    position: relative;
}

.publication-item:hover {
    transform: translateY(-5px);
    border-color: var(--accent-cyan);
    box-shadow: 0 15px 40px rgba(125, 211, 252, 0.2);
}

.publication-type {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-purple), var(--accent-pink));
    color: white;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.publication-item h3 {
    color: var(--text-primary);
    font-size: 1.3rem;
    margin-bottom: 1rem;
    font-weight: 700;
    line-height: 1.4;
}

.publication-authors {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-style: italic;
}

.publication-venue {
    color: var(--accent-cyan);
    font-weight: 600;
    margin-bottom: 1rem;
}

.publication-abstract {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.publication-metrics {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.metric-badge {
    background: var(--tertiary-bg);
    color: var(--accent-emerald);
    padding: 0.4rem 0.8rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.publication-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.6rem 1rem;
    background: transparent;
    color: var(--accent-cyan);
    border: 1px solid var(--accent-cyan);
    border-radius: var(--border-radius);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 500;
    transition: var(--transition-smooth);
}

.pub-link:hover {
    background: var(--accent-cyan);
    color: var(--primary-bg);
    transform: translateY(-2px);
}

/* ==========================================
   CERTIFICATIONS SECTION
   ========================================== */

.certifications-section {
    margin-top: 4rem;
    padding-top: 3rem;
    border-top: 1px solid var(--border-subtle);
}

.certifications-section h3 {
    font-size: 1.8rem;
    color: var(--text-primary);
    margin-bottom: 2rem;
    text-align: center;
}

.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.cert-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--secondary-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-subtle);
    transition: var(--transition-smooth);
}

.cert-item:hover {
    transform: translateY(-3px);
    border-color: var(--accent-cyan);
    box-shadow: 0 10px 25px rgba(125, 211, 252, 0.2);
}

.cert-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-bg);
    font-size: 1.2rem;
    flex-shrink: 0;
}

.cert-content h4 {
    color: var(--text-primary);
    font-size: 1rem;
    margin-bottom: 0.2rem;
    font-weight: 600;
}

.cert-date {
    color: var(--text-tertiary);
    font-size: 0.9rem;
    font-family: var(--font-mono);
}

/* ==========================================
   ENHANCED CONTACT SECTION
   ========================================== */

.contact-container {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 4rem;
    align-items: start;
    margin-top: 3rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--secondary-bg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-subtle);
    transition: var(--transition-smooth);
}

.contact-item:hover {
    transform: translateY(-3px);
    border-color: var(--accent-cyan);
    box-shadow: 0 10px 25px rgba(125, 211, 252, 0.2);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-bg);
    font-size: 1.2rem;
    flex-shrink: 0;
}

.contact-details h4 {
    color: var(--text-primary);
    font-size: 1.1rem;
    margin-bottom: 0.2rem;
    font-weight: 600;
}

.contact-details p {
    color: var(--text-secondary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

/* ==========================================
   RESPONSIVE UPDATES
   ========================================== */

@media (max-width: 768px) {
    .experience-timeline::before {
        left: 30px;
    }
    
    .timeline-item {
        flex-direction: row !important;
    }
    
    .timeline-marker {
        left: 30px;
        transform: translateX(-50%);
    }
    
    .timeline-content {
        width: calc(100% - 80px);
        margin-left: 80px !important;
        margin-right: 0 !important;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .certifications-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-container {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .project-metrics {
        flex-direction: column;
        gap: 1rem;
    }
    
    .publication-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .timeline-content {
        padding: 1.5rem;
    }
    
    .research-category,
    .publication-item {
        padding: 1.5rem;
    }
    
    .project-metrics {
        padding: 0.8rem;
    }
    
    .contact-item {
        padding: 1rem;
    }
    
    .cert-item {
        padding: 1rem;
    }
}

/* ==========================================
   PROJECTS SECTION
   ========================================== */

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 3rem;
    margin-top: 3rem;
}

.project-card {
    background: var(--secondary-bg);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    border: 1px solid var(--border-subtle);
    transition: var(--transition-spring);
    position: relative;
    group: true;
}

.project-card:hover {
    transform: translateY(-10px);
    border-color: var(--accent-cyan);
    box-shadow: 0 25px 60px rgba(125, 211, 252, 0.2);
}

.project-header {
    height: 250px;
    background: linear-gradient(135deg, var(--tertiary-bg), var(--primary-bg));
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.project-icon {
    font-size: 4rem;
    color: var(--accent-cyan);
    z-index: 2;
    transition: var(--transition-smooth);
}

.project-card:hover .project-icon {
    transform: scale(1.1);
    color: var(--accent-emerald);
}

.project-header::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, var(--glow-cyan), transparent);
    opacity: 0;
    transition: var(--transition-smooth);
    animation: rotate 10s linear infinite;
}

.project-card:hover .project-header::before {
    opacity: 0.1;
}

@keyframes rotate {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.project-content {
    padding: 2.5rem;
}

.project-title {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 700;
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 2rem;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-bottom: 2rem;
}

.tech-tag {
    background: var(--tertiary-bg);
    color: var(--accent-purple);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    font-family: var(--font-mono);
    border: 1px solid var(--border-subtle);
    transition: var(--transition-smooth);
}

.tech-tag:hover {
    background: var(--accent-purple);
    color: var(--primary-bg);
    transform: translateY(-2px);
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.8rem 1.5rem;
    border-radius: var(--border-radius);
    font-family: var(--font-mono);
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition-smooth);
    font-size: 0.9rem;
}

.project-link.primary {
    background: var(--accent-cyan);
    color: var(--primary-bg);
}

.project-link.secondary {
    background: transparent;
    color: var(--accent-cyan);
    border: 2px solid var(--accent-cyan);
}

.project-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px var(--glow-cyan);
}

/* ==========================================
   CONTACT SECTION
   ========================================== */

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

.contact-form {
    display: grid;
    gap: 2rem;
    margin-top: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.form-input {
    padding: 1.2rem 1.5rem;
    background: var(--secondary-bg);
    border: 2px solid var(--border-subtle);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 1rem;
    transition: var(--transition-smooth);
}

.form-input:focus {
    outline: none;
    border-color: var(--accent-cyan);
    box-shadow: 0 0 0 4px var(--glow-cyan);
}

.form-textarea {
    grid-column: 1 / -1;
    min-height: 150px;
    resize: vertical;
}

.submit-btn {
    padding: 1.2rem 2.5rem;
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald));
    color: var(--primary-bg);
    border: none;
    border-radius: var(--border-radius);
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition-spring);
    position: relative;
    overflow: hidden;
}

.submit-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px var(--glow-cyan);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* ==========================================
   FOOTER
   ========================================== */

footer {
    background: var(--primary-bg);
    border-top: 1px solid var(--border-subtle);
    padding: 4rem 0 2rem;
    text-align: center;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 3rem;
}

.social-link {
    width: 60px;
    height: 60px;
    background: var(--secondary-bg);
    border: 2px solid var(--border-subtle);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 1.5rem;
    transition: var(--transition-spring);
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-emerald));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.social-link:hover {
    transform: translateY(-5px) scale(1.1);
    border-color: var(--accent-cyan);
    color: var(--primary-bg);
}

.social-link:hover::before {
    opacity: 1;
}

.social-link i {
    position: relative;
    z-index: 2;
}

.footer-text {
    color: var(--text-tertiary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

/* ==========================================
   ANIMATIONS
   ========================================== */

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

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

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-20px);
    }
}

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==========================================
   RESPONSIVE DESIGN
   ========================================== */

@media (max-width: 768px) {
    :root {
        --border-radius: 8px;
        --border-radius-lg: 12px;
    }

    .container {
        padding: 0 20px;
    }

    .nav-links {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background: rgba(13, 17, 23, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: flex-start;
        align-items: center;
        padding-top: 3rem;
        gap: 2rem;
        transition: left 0.3s ease;
    }

    .nav-links.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(6px, 6px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(6px, -6px);
    }

    .hero h1 {
        font-size: clamp(2.5rem, 8vw, 4rem);
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .cta-group {
        flex-direction: column;
        align-items: center;
    }

    .about-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

    .profile-pic {
        width: 220px;
        height: 220px;
        font-size: 3.5rem;
    }

    .stats-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .skills-container {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .projects-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .social-links {
        gap: 1rem;
    }

    .social-link {
        width: 50px;
        height: 50px;
        font-size: 1.2rem;
    }

    .section {
        padding: 80px 0;
    }

    .section-header {
        margin-bottom: 3rem;
    }
}

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

    .hero {
        padding: 2rem 0;
    }

    .hero-content {
        padding: 1rem;
    }

    .profile-pic {
        width: 180px;
        height: 180px;
        font-size: 3rem;
    }

    .skill-category,
    .project-content {
        padding: 1.5rem;
    }

    .section {
        padding: 60px 0;
    }
}

/* ==========================================
   UTILITY CLASSES
   ========================================== */

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }

.font-mono { font-family: var(--font-mono); }
.font-sans { font-family: var(--font-sans); }

.accent-text { color: var(--accent-cyan); }
.muted-text { color: var(--text-secondary); }

/* ==========================================
   SCROLL PROGRESS BAR
   ========================================== */

.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-emerald), var(--accent-purple));
    z-index: 9999;
    transition: width 0.1s ease;
}