/* ===================================
   Global Styles & CSS Variables
   =================================== */
:root {
    /* Color Palette */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #8b5cf6;
    --accent-color: #f59e0b;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-dark: #0f172a;
    --bg-card: #ffffff;
    
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --text-white: #ffffff;
    
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-heading: 'Poppins', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
}

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

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

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

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
}

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

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

/* Section Styles */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-full);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-top: var(--spacing-md);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.875rem 1.75rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: var(--text-white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: var(--text-white);
    transform: translateY(-2px);
}

/* ===================================
   Navigation
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
    background: rgba(255, 255, 255, 0.98);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
}

.nav-brand a {
    font-size: 1.75rem;
    font-weight: 700;
    font-family: var(--font-heading);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

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

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: var(--transition-base);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-link {
    color: var(--text-primary);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.5rem 0;
    position: relative;
}

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

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

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding-top: 80px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(99, 102, 241, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(139, 92, 246, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 40% 90%, rgba(59, 130, 246, 0.3) 0%, transparent 50%);
    opacity: 0.6;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--text-white);
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: rgba(255, 255, 255, 0.95);
}

.hero-tagline {
    font-size: 1.25rem;
    font-style: italic;
    margin-bottom: var(--spacing-lg);
    color: rgba(255, 255, 255, 0.9);
}

.hero-description {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
    color: rgba(255, 255, 255, 0.9);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--spacing-xl);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
    margin-top: var(--spacing-2xl);
}

.stat-item {
    text-align: center;
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-lg);
    min-width: 140px;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-white);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator a {
    color: var(--text-white);
    font-size: 1.5rem;
}

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

/* ===================================
   About Section
   =================================== */
.about-section {
    background: var(--bg-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: start;
}

.about-text h3 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.about-text p {
    font-size: 1.0625rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.about-info {
    margin-top: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.info-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1rem;
    color: var(--text-secondary);
}

.info-item i {
    color: var(--primary-color);
    width: 20px;
}

.about-highlights {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
}

.highlight-card {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    transition: all var(--transition-base);
}

.highlight-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-md);
}

.highlight-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.highlight-card h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.highlight-card p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===================================
   Skills Section
   =================================== */
.skills-section {
    background: var(--bg-secondary);
}

.skills-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.skill-category {
    background: var(--bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.skill-category:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.category-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.category-header i {
    font-size: 2rem;
    color: var(--primary-color);
}

.category-header h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
}

.skill-items {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.skill-item {
    margin-bottom: var(--spacing-xs);
}

.skill-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-xs);
}

.skill-name {
    font-weight: 600;
    color: var(--text-primary);
}

.skill-level {
    font-weight: 600;
    color: var(--primary-color);
}

.skill-bar {
    height: 8px;
    background: var(--bg-secondary);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-full);
    width: 0;
    transition: width 1s ease-out;
}

.tool-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

.tool-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.tool-item:hover {
    background: var(--primary-color);
    color: var(--text-white);
    transform: scale(1.05);
}

.tool-item i {
    font-size: 2rem;
    color: var(--primary-color);
    transition: color var(--transition-base);
}

.tool-item:hover i {
    color: var(--text-white);
}

.tool-item span {
    font-size: 0.875rem;
    font-weight: 600;
    text-align: center;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.skill-tag {
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.skill-tag:hover {
    background: var(--primary-color);
    color: var(--text-white);
    transform: translateY(-2px);
}

/* ===================================
   Experience Section
   =================================== */
.experience-section {
    background: var(--bg-primary);
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--primary-color), var(--secondary-color));
}

.timeline-item {
    position: relative;
    padding-left: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.timeline-marker {
    position: absolute;
    left: -8px;
    top: 0;
    width: 18px;
    height: 18px;
    background: var(--primary-color);
    border: 3px solid var(--bg-primary);
    border-radius: 50%;
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.2);
}

.timeline-content {
    background: var(--bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.timeline-content:hover {
    box-shadow: var(--shadow-lg);
    transform: translateX(5px);
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.experience-header h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.experience-header h4 {
    font-size: 1.125rem;
    color: var(--primary-color);
    font-weight: 600;
}

.experience-period {
    background: var(--bg-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.project-card {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-md);
}

.project-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.project-title i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.project-title h5 {
    font-size: 1.25rem;
    color: var(--text-primary);
}

.project-impact {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.impact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0.75rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--accent-color);
}

.impact-item i {
    color: var(--accent-color);
    font-size: 1.125rem;
}

.impact-item span {
    font-size: 0.9375rem;
    color: var(--text-primary);
    font-weight: 500;
}

.project-description {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

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

.tag {
    padding: 0.375rem 0.875rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.tag:hover {
    background: var(--primary-color);
    color: var(--text-white);
    border-color: var(--primary-color);
}

/* ===================================
   Projects Section
   =================================== */
.projects-section {
    background: var(--bg-secondary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-lg);
}

.project-item {
    background: var(--bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    border-top: 4px solid var(--primary-color);
}

.project-item:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.project-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

.project-icon i {
    font-size: 1.75rem;
    color: var(--text-white);
}

.project-item h3 {
    font-size: 1.375rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.project-domain {
    font-size: 0.875rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.project-desc {
    font-size: 0.9375rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.project-impact-metrics {
    display: flex;
    justify-content: space-around;
    gap: var(--spacing-sm);
    margin: var(--spacing-lg) 0;
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

.metric {
    text-align: center;
}

.metric-value {
    display: block;
    font-size: 1.75rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.metric-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

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

.tool-badge {
    padding: 0.375rem 0.75rem;
    background: var(--bg-secondary);
    border-radius: var(--radius-full);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-primary);
}

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

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.625rem 1.25rem;
    background: var(--primary-color);
    color: var(--text-white);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    transition: all var(--transition-base);
}

.project-link:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

/* ===================================
   Education Section
   =================================== */
.education-section {
    background: var(--bg-primary);
}

.subsection-title {
    font-size: 1.75rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.subsection-title:first-of-type {
    margin-top: 0;
}

.education-item {
    display: flex;
    gap: var(--spacing-lg);
    background: var(--bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.education-item:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-5px);
}

.education-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.education-icon i {
    font-size: 2rem;
    color: var(--text-white);
}

.education-details h4 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.institution {
    font-size: 1.125rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.education-meta {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.education-meta span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.education-meta i {
    color: var(--primary-color);
}

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

.cert-item {
    background: var(--bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all var(--transition-base);
    border-top: 4px solid var(--primary-color);
}

.cert-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.cert-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-md);
}

.cert-icon i {
    font-size: 1.75rem;
    color: var(--text-white);
}

.cert-item h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    min-height: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.cert-code {
    font-size: 0.875rem;
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.cert-issuer {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

/* ===================================
   Contact Section
   =================================== */
.contact-section {
    background: var(--bg-secondary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-2xl);
}

.contact-info h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.contact-info > p {
    font-size: 1.0625rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.contact-item {
    display: flex;
    gap: var(--spacing-md);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-icon i {
    font-size: 1.25rem;
    color: var(--text-white);
}

.contact-text h4 {
    font-size: 1.125rem;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.contact-text p,
.contact-text a {
    font-size: 1rem;
    color: var(--text-secondary);
}

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

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

.social-link {
    width: 50px;
    height: 50px;
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.social-link:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: var(--text-white);
    transform: translateY(-3px);
}

.contact-form-container {
    background: var(--bg-card);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9375rem;
}

.form-group input,
.form-group textarea {
    padding: 0.875rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: var(--font-primary);
    font-size: 1rem;
    color: var(--text-primary);
    transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.btn-submit {
    margin-top: var(--spacing-sm);
}

.form-message {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    font-weight: 500;
    text-align: center;
    display: none;
}

.form-message.success {
    background: #d1fae5;
    color: #065f46;
    display: block;
}

.form-message.error {
    background: #fee2e2;
    color: #991b1b;
    display: block;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--bg-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-brand h3 {
    font-size: 1.5rem;
    color: var(--text-white);
    margin-bottom: var(--spacing-xs);
}

.footer-brand p {
    margin-bottom: 0.5rem;
}

.footer-tagline {
    font-style: italic;
    color: rgba(255, 255, 255, 0.6);
    margin-top: var(--spacing-sm);
}

.footer-links h4,
.footer-contact h4 {
    color: var(--text-white);
    margin-bottom: var(--spacing-md);
    font-size: 1.125rem;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-xs);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--text-white);
}

.footer-contact p {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    color: rgba(255, 255, 255, 0.7);
}

.footer-contact i {
    color: var(--primary-light);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

.footer-bottom p {
    margin-bottom: 0.25rem;
}

/* ===================================
   Scroll to Top Button
   =================================== */
.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--text-white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: 999;
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 992px) {
    .hero-title {
        font-size: 3rem;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .skills-container {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-contact p {
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background: var(--bg-card);
        width: 100%;
        padding: var(--spacing-lg);
        box-shadow: var(--shadow-lg);
        transition: left var(--transition-base);
        align-items: flex-start;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.25rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
        max-width: 300px;
        margin: 0 auto var(--spacing-xl);
    }
    
    .hero-buttons .btn {
        width: 100%;
        justify-content: center;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .tool-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .timeline::before {
        left: 8px;
    }
    
    .timeline-item {
        padding-left: var(--spacing-xl);
    }
    
    .timeline-marker {
        left: 0;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .certifications-grid {
        grid-template-columns: 1fr;
    }
    
    .project-impact-metrics {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.125rem;
    }
    
    .hero-tagline {
        font-size: 1rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .hero-stats {
        gap: var(--spacing-md);
    }
    
    .stat-item {
        min-width: 100px;
        padding: var(--spacing-sm);
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .about-text h3 {
        font-size: 1.5rem;
    }
    
    .tool-grid {
        grid-template-columns: 1fr;
    }
    
    .experience-header {
        flex-direction: column;
    }
    
    .scroll-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}