/* CSS Variables */
:root {
    --bg-primary: #0a0a0a;
    --bg-secondary: #121212;
    --bg-surface: #1a1a1a;
    --bg-card: #1e1e1e;
    --text-primary: #f9fafb;
    --text-secondary: #e5e7eb;
    --text-muted: #9ca3af;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --border: #2d2d2d;
    --border-light: #3a3a3a;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --transition: 0.3s ease;
    --border-radius: 8px;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.5);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    font-size: 16px;
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

h4 {
    font-size: 1.25rem;
}

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

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

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

code, .monospace {
    font-family: 'SF Mono', 'Monaco', 'Consolas', 'Courier New', monospace;
}

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

/* Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: background-color var(--transition);
}

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

.nav-logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.05em;
}

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

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

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color var(--transition);
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent);
    transition: width var(--transition);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background-color: var(--text-primary);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl) var(--spacing-md);
    padding-top: 100px;
    background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-container {
    max-width: 800px;
    text-align: center;
}

.hero-image-wrapper {
    margin-bottom: var(--spacing-lg);
    display: inline-block;
}

.hero-image {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--border-light);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition);
}

.hero-image:hover {
    transform: scale(1.05);
}

.hero-name {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
    letter-spacing: 0.1em;
    font-weight: 700;
}

.hero-tagline {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-lg);
    font-weight: 400;
}

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

.contact-link {
    color: var(--text-secondary);
    font-size: 0.95rem;
    transition: color var(--transition);
}

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

/* Section Styles */
.section {
    padding: var(--spacing-2xl) 0;
    border-top: 1px solid var(--border);
}

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

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background-color: var(--accent);
}

/* Experience Section */
.experience-timeline {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.experience-item {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    transition: transform var(--transition), box-shadow var(--transition);
    opacity: 0;
    transform: translateY(20px);
}

.experience-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.experience-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-light);
}

.experience-header {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    align-items: flex-start;
}

.experience-logo-wrapper {
    flex-shrink: 0;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-surface);
    border-radius: var(--border-radius);
    border: 1px solid var(--border);
    padding: var(--spacing-xs);
}

.experience-logo {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.experience-info {
    flex: 1;
}

.experience-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
    color: var(--accent);
}

.experience-company {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.experience-location,
.experience-date {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: var(--spacing-xs);
}

.experience-content {
    margin-top: var(--spacing-md);
}

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

.experience-list li {
    padding-left: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
    position: relative;
    color: var(--text-secondary);
    line-height: 1.8;
}

.experience-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: bold;
}

.experience-list li strong {
    color: var(--text-primary);
    font-weight: 600;
}

/* Education Section */
.education-item {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    max-width: 800px;
    margin: 0 auto;
    opacity: 0;
    transform: translateY(20px);
}

.education-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.education-institution {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-xs);
    color: var(--accent);
}

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

.education-location,
.education-date {
    color: var(--text-muted);
    margin-bottom: var(--spacing-xs);
}

.education-details {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border);
}

.education-details p {
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
}

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

.skill-category {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    opacity: 0;
    transform: translateY(20px);
}

.skill-category.visible {
    opacity: 1;
    transform: translateY(0);
}

.skill-category-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
    color: var(--accent);
    text-align: center;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    justify-content: center;
}

.skill-tag {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: all var(--transition);
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
}

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

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    max-width: 1200px;
    margin: 0 auto;
}

.project-item {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    transition: transform var(--transition), box-shadow var(--transition);
    opacity: 0;
    transform: translateY(20px);
}

.project-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.project-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-light);
}

.project-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--accent);
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.project-technologies {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border);
}

/* References Section */
.references-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    max-width: 1000px;
    margin: 0 auto;
}

.reference-item {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    text-align: center;
    opacity: 0;
    transform: translateY(20px);
}

.reference-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.reference-name {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
    color: var(--accent);
}

.reference-title {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    font-style: italic;
}

.reference-affiliation {
    color: var(--text-muted);
    margin-bottom: var(--spacing-sm);
}

.reference-email {
    color: var(--accent);
    font-size: 0.95rem;
    display: inline-block;
    margin-top: var(--spacing-xs);
}

.reference-email:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    background-color: var(--bg-surface);
    border-top: 1px solid var(--border);
    padding: var(--spacing-lg) 0;
    text-align: center;
}

.footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Fade-in Animation */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --spacing-xl: 2rem;
        --spacing-2xl: 3rem;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.75rem;
    }

    .hero-name {
        font-size: 2rem;
    }

    .hero-tagline {
        font-size: 1rem;
    }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background-color: var(--bg-surface);
        width: 100%;
        text-align: center;
        transition: left var(--transition);
        border-top: 1px solid var(--border);
        padding: var(--spacing-md) 0;
        gap: var(--spacing-sm);
    }

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

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

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

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero-contact {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .experience-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .experience-logo-wrapper {
        width: 100px;
        height: 100px;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }

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

    .references-grid {
        grid-template-columns: 1fr;
    }

    .section-title {
        font-size: 2rem;
    }
}

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

    .hero-image {
        width: 150px;
        height: 150px;
    }

    .experience-item,
    .education-item,
    .skill-category,
    .project-item,
    .reference-item {
        padding: var(--spacing-md);
    }
}

/* Print Styles */
@media print {
    .header,
    .footer {
        display: none;
    }

    .section {
        page-break-inside: avoid;
    }
}