:root {
    --color-primary: #1e3a8a;
    --color-primary-light: #3b82f6;
    --color-primary-dark: #1e293b;
    
    --color-charcoal: #2d3748;
    --color-text: #1f2937;
    --color-text-light: #6b7280;
    
    --color-bg: #ffffff;
    --color-bg-secondary: #f8fafc;
    --color-bg-tertiary: #f1f5f9;
    
    --color-accent: #3b82f6;
    --color-success: #059669;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-mono: 'Courier New', Courier, monospace;
}

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

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

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

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

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

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

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

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

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

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all 0.3s ease;
}

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

.nav-brand a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    font-family: var(--font-mono);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-link {
    color: var(--color-text);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.nav-link:hover {
    background-color: var(--color-bg-tertiary);
    color: var(--color-primary);
}

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

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--color-primary);
    margin: 3px 0;
    transition: 0.3s;
    border-radius: 3px;
}

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--color-bg-secondary) 0%, var(--color-bg) 100%);
    padding-top: 80px;
}

.hero-content {
    text-align: center;
    animation: fadeInUp 1s ease;
}

.hero-title {
    margin-bottom: var(--spacing-sm);
}

.greeting {
    display: block;
    font-size: 1.5rem;
    color: var(--color-text-light);
    font-weight: 400;
    margin-bottom: var(--spacing-xs);
}

.name {
    display: block;
    font-size: 3.5rem;
    color: var(--color-primary);
    font-weight: 700;
}

.hero-subtitle {
    font-size: 2rem;
    color: var(--color-charcoal);
    margin-bottom: var(--spacing-md);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-light);
    max-width: 600px;
    margin: 0 auto var(--spacing-md);
    line-height: 1.8;
}

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

.social-links {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
}

.social-links a {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-bg-tertiary);
    border-radius: 50%;
    color: var(--color-primary);
    font-size: 1.25rem;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background-color: var(--color-primary);
    color: white;
    transform: translateY(-5px);
}

.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 6px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

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

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1.125rem;
}

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

.section-title {
    text-align: center;
    font-size: 2.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    position: relative;
    padding-bottom: var(--spacing-sm);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background-color: var(--color-accent);
    border-radius: 2px;
}

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

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

.about-text p {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

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

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.project-card {
    background-color: var(--color-bg);
    border-radius: 8px;
    padding: var(--spacing-md);
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border: 1px solid var(--color-bg-tertiary);
}

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

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

.project-icon {
    font-size: 2rem;
    color: var(--color-primary);
}

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

.project-links a {
    color: var(--color-text-light);
    font-size: 1.25rem;
    transition: color 0.3s ease;
}

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

.project-title {
    font-size: 1.5rem;
    color: var(--color-primary-dark);
    margin-bottom: var(--spacing-sm);
}

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

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

.tech-tag {
    background-color: var(--color-bg-tertiary);
    color: var(--color-primary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

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

.section-description {
    text-align: center;
    color: var(--color-text-light);
    font-size: 1.125rem;
    max-width: 700px;
    margin: -2rem auto 3rem;
}

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

.video-card {
    background-color: var(--color-bg-secondary);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

.video-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.video-wrapper {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    background-color: var(--color-charcoal);
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.video-info {
    padding: var(--spacing-md);
}

.video-title {
    font-size: 1.25rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.video-description {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-sm);
    line-height: 1.6;
}

.skills {
    background-color: var(--color-bg);
}

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

.skill-category {
    background-color: var(--color-bg-secondary);
    padding: var(--spacing-md);
    border-radius: 8px;
    border: 2px solid var(--color-bg-tertiary);
    transition: all 0.3s ease;
}

.skill-category:hover {
    border-color: var(--color-accent);
    box-shadow: var(--shadow-md);
}

.skill-category-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    font-size: 1.25rem;
}

.skill-category-title i {
    font-size: 1.5rem;
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.skill-item {
    background-color: var(--color-bg);
    color: var(--color-text);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    border: 1px solid var(--color-bg-tertiary);
    transition: all 0.3s ease;
}

.skill-item:hover {
    background-color: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}

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

.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    padding-left: var(--spacing-md);
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background-color: var(--color-accent);
}

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

.timeline-dot {
    position: absolute;
    left: -0.5rem;
    top: 0;
    width: 1rem;
    height: 1rem;
    background-color: var(--color-accent);
    border-radius: 50%;
    border: 3px solid var(--color-bg-secondary);
}

.timeline-content {
    background-color: var(--color-bg);
    padding: var(--spacing-md);
    border-radius: 8px;
    box-shadow: var(--shadow-md);
}

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

.timeline-header h3 {
    color: var(--color-primary);
    font-size: 1.25rem;
}

.timeline-date {
    color: var(--color-text-light);
    font-weight: 600;
    font-size: 0.9rem;
}

.timeline-company {
    color: var(--color-charcoal);
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
}

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

.timeline-description li {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xs);
    padding-left: 1.5rem;
    position: relative;
}

.timeline-description li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-weight: bold;
}

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

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-md);
}

.education-card {
    background-color: var(--color-bg);
    padding: var(--spacing-md);
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    display: flex;
    gap: var(--spacing-md);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.education-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-accent);
}

.education-icon {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.75rem;
}

.education-content {
    flex: 1;
}

.education-degree {
    font-size: 1.25rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.education-school {
    color: var(--color-charcoal);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.education-date {
    display: inline-block;
    color: var(--color-text-light);
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    padding: 0.25rem 0.75rem;
    background-color: var(--color-bg-tertiary);
    border-radius: 20px;
}

.education-description {
    color: var(--color-text-light);
    line-height: 1.6;
    margin-bottom: var(--spacing-sm);
}

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

.highlight-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--color-text);
    font-size: 0.9rem;
}

.highlight-item i {
    color: var(--color-success);
    font-size: 1rem;
}

.certifications-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.cert-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background-color: var(--color-bg-secondary);
    border-radius: 6px;
    color: var(--color-text);
    font-weight: 500;
    transition: all 0.3s ease;
}

.cert-item:hover {
    background-color: var(--color-primary);
    color: white;
}

.cert-item i {
    color: var(--color-accent);
    font-size: 1.25rem;
}

.cert-item:hover i {
    color: white;
}

.contact {
    background-color: var(--color-bg);
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-description {
    font-size: 1.125rem;
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

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

.contact-method {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background-color: var(--color-bg-secondary);
    border-radius: 8px;
    color: var(--color-text);
    transition: all 0.3s ease;
}

.contact-method:hover {
    background-color: var(--color-primary);
    color: white;
    transform: translateX(10px);
}

.contact-method i {
    font-size: 1.5rem;
}

.footer {
    background-color: var(--color-primary-dark);
    color: white;
    text-align: center;
    padding: var(--spacing-md) 0;
}

.footer p {
    color: rgba(255, 255, 255, 0.8);
    margin: 0;
}

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

.fade-in {
    animation: fadeInUp 0.6s ease;
}

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background-color: white;
        width: 100%;
        padding: var(--spacing-md);
        box-shadow: var(--shadow-lg);
        transition: left 0.3s ease;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .name {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.5rem;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .video-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .education-grid {
        grid-template-columns: 1fr;
    }
    
    .education-card {
        flex-direction: column;
        text-align: center;
    }
    
    .education-icon {
        margin: 0 auto;
    }
    
    .timeline-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    section {
        padding: var(--spacing-lg) 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero-cta .btn {
        width: 100%;
        text-align: center;
    }
}

@media print {
    .navbar,
    .hero-cta,
    .social-links,
    .footer {
        display: none;
    }
    
    section {
        page-break-inside: avoid;
        padding: var(--spacing-sm) 0;
    }
}