/* ==================== RESET & BASE ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #0f172a;
    --accent-color: #06b6d4;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    --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);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);

    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    --font-mono: 'Courier New', monospace;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Border radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
}

html {
    scroll-behavior: smooth;
}

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

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

section {
    padding: var(--spacing-2xl) 0;
}

/* ==================== 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: var(--transition-base);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition-fast);
}

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

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

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition-base);
}

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

.nav-link {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
    transition: var(--transition-fast);
}

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

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

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

/* ==================== HERO SECTION ==================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding-top: 80px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
    overflow: hidden;
}

.hero-shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.1;
    animation: float 20s infinite ease-in-out;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: var(--primary-color);
    top: -100px;
    right: -100px;
    animation-delay: 0s;
}

.shape-2 {
    width: 300px;
    height: 300px;
    background: var(--accent-color);
    bottom: -100px;
    left: -100px;
    animation-delay: 7s;
}

.shape-3 {
    width: 200px;
    height: 200px;
    background: var(--primary-light);
    top: 50%;
    left: 50%;
    animation-delay: 3s;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) rotate(0deg);
    }
    33% {
        transform: translate(30px, -30px) rotate(120deg);
    }
    66% {
        transform: translate(-20px, 20px) rotate(240deg);
    }
}

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

.hero-text {
    animation: fadeInUp 1s ease-out;
}

.hero-greeting {
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
}

.hero-name {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.hero-title {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    line-height: 1.4;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    max-width: 600px;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.btn {
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-base);
    display: inline-block;
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

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

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

.hero-social a:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeInRight 1s ease-out;
}

.image-placeholder {
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-xl);
    position: relative;
    overflow: hidden;
}

.image-placeholder::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%) translateY(-100%) rotate(45deg);
    }
    100% {
        transform: translateX(100%) translateY(100%) rotate(45deg);
    }
}

.image-placeholder i {
    font-size: 10rem;
    color: rgba(255, 255, 255, 0.8);
    z-index: 1;
}

.scroll-down {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--text-secondary);
    font-size: 1.5rem;
    animation: bounce 2s infinite;
}

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

/* ==================== SECTION HEADERS ==================== */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--primary-color);
    border-radius: 2px;
}

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

/* ==================== ABOUT SECTION ==================== */
.about {
    background: var(--bg-secondary);
}

.about-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

.about-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.info-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

.info-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.info-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.info-text h4 {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.info-text p {
    font-size: 1.125rem;
    color: var(--text-primary);
    font-weight: 600;
}

.timeline {
    margin-top: var(--spacing-lg);
}

.timeline-title {
    font-size: 1.75rem;
    color: var(--secondary-color);
    margin-bottom: var(--spacing-lg);
    font-weight: 600;
}

.timeline-item {
    position: relative;
    padding-left: 40px;
    padding-bottom: var(--spacing-lg);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 11px;
    top: 30px;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

.timeline-item:last-child::before {
    display: none;
}

.timeline-dot {
    position: absolute;
    left: 0;
    top: 5px;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 4px solid var(--bg-secondary);
    box-shadow: 0 0 0 2px var(--primary-color);
}

.timeline-content {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

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

.timeline-date {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.timeline-content h4 {
    font-size: 1.25rem;
    color: var(--secondary-color);
    margin-bottom: 0.25rem;
}

.timeline-subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.timeline-location {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-style: italic;
    margin-bottom: 0.5rem;
}

.timeline-details {
    list-style: none;
    margin-top: 0.75rem;
}

.timeline-details li {
    padding-left: 1.5rem;
    position: relative;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

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

.soft-skills {
    margin-top: var(--spacing-lg);
}

.soft-skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.soft-skill {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

.soft-skill:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

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

.soft-skill p {
    font-weight: 500;
    color: var(--text-primary);
}

/* ==================== SKILLS SECTION ==================== */
.skills {
    background: white;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.skill-category {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

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

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

.category-header i {
    font-size: 1.75rem;
    color: var(--primary-color);
}

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

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

.skill-tag {
    padding: 0.5rem 1rem;
    background: white;
    color: var(--text-primary);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    box-shadow: var(--shadow-sm);
    transition: var(--transition-fast);
}

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

.languages-section {
    margin-top: var(--spacing-2xl);
}

.languages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.language-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

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

.language-item h4 {
    font-size: 1.125rem;
    color: var(--secondary-color);
    margin-bottom: 0.25rem;
}

.language-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ==================== PROJECTS SECTION ==================== */
.projects {
    background: var(--bg-secondary);
}

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

.project-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
    display: flex;
    flex-direction: column;
}

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

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

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

.project-badge {
    padding: 0.375rem 0.75rem;
    background: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.project-badge-academic {
    background: var(--accent-color);
}

.project-card h3 {
    font-size: 1.25rem;
    color: var(--secondary-color);
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

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

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: auto;
}

.tech-tag {
    padding: 0.375rem 0.75rem;
    background: var(--bg-secondary);
    color: var(--primary-color);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    border: 1px solid var(--border-color);
}

/* ==================== CONTACT SECTION ==================== */
.contact {
    background: white;
}

.contact-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

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

.contact-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

.contact-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.contact-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-details h4 {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
    text-transform: uppercase;
    font-weight: 600;
}

.contact-details a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-fast);
}

.contact-details a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.contact-details p {
    color: var(--text-primary);
    font-weight: 600;
}

.interests-section {
    margin-top: var(--spacing-lg);
}

.interests-section h3 {
    font-size: 1.75rem;
    color: var(--secondary-color);
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.interest-card {
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: var(--transition-base);
}

.interest-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.interest-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.interest-card h4 {
    font-size: 1.125rem;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.interest-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ==================== FOOTER ==================== */
.footer {
    background: var(--secondary-color);
    color: white;
    padding: var(--spacing-lg) 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer-social {
    display: flex;
    gap: var(--spacing-sm);
}

.footer-social a {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: var(--transition-base);
}

.footer-social a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

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

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

.fade-in {
    animation: fadeInUp 0.6s ease-out forwards;
    opacity: 0;
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 968px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-name {
        font-size: 2.5rem;
    }

    .hero-title {
        font-size: 1.25rem;
    }

    .hero-cta {
        justify-content: center;
    }

    .hero-social {
        justify-content: center;
    }

    .hero-image {
        order: -1;
    }

    .image-placeholder {
        width: 300px;
        height: 300px;
    }

    .image-placeholder i {
        font-size: 7rem;
    }

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

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        gap: 0;
        padding: var(--spacing-md);
        box-shadow: var(--shadow-md);
        max-height: 0;
        overflow: hidden;
        transition: var(--transition-base);
    }

    .nav-menu.active {
        max-height: 400px;
    }

    .nav-link {
        padding: var(--spacing-sm) 0;
    }

    .hero {
        min-height: auto;
        padding: 100px 0 var(--spacing-2xl);
    }

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

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

@media (max-width: 480px) {
    .hero-name {
        font-size: 2rem;
    }

    .hero-title {
        font-size: 1.125rem;
    }

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

    .image-placeholder {
        width: 250px;
        height: 250px;
    }

    .image-placeholder i {
        font-size: 5rem;
    }

    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.875rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}