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

/* Root Variables */
:root {
    --color-primary: #2563eb;
    --color-text: #1f2937;
    --color-text-light: #6b7280;
    --color-background: #ffffff;
    --color-surface: #f9fafb;
    --color-border: #e5e7eb;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-base: 16px;
    --line-height-base: 1.6;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --border-radius: 8px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --transition: all 0.2s ease-in-out;
}

/* Base Styles */
html {
    scroll-behavior: smooth;
    font-size: var(--font-size-base);
}

body {
    font-family: var(--font-family);
    line-height: var(--line-height-base);
    color: var(--color-text);
    background-color: var(--color-background);
}

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

@media (min-width: 768px) {
    .container {
        padding: 0 var(--spacing-lg);
    }
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
}

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

.nav-logo {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
    transition: var(--transition);
}

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

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--color-text-light);
    text-decoration: none;
    font-weight: 400;
    transition: var(--transition);
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: width 0.3s ease;
}

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

/* Main Content */
.main {
    margin-top: 80px;
}

/* Hero Section */
.hero {
    padding: var(--spacing-2xl) 0;
    min-height: 80vh;
    display: flex;
    align-items: center;
}

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

@media (min-width: 768px) {
    .hero .container {
        grid-template-columns: 1fr 300px;
        gap: var(--spacing-2xl);
    }
}

.hero-content {
    text-align: center;
}

@media (min-width: 768px) {
    .hero-content {
        text-align: left;
    }
}

.hero-title {
    font-size: 3rem;
    font-weight: 300;
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
}

@media (min-width: 768px) {
    .hero-title {
        font-size: 4rem;
    }
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xl);
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

@media (min-width: 768px) {
    .hero-subtitle {
        margin-left: 0;
        margin-right: 0;
    }
}

.hero-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

@media (min-width: 768px) {
    .hero-actions {
        justify-content: flex-start;
    }
}

.hero-image {
    display: flex;
    justify-content: center;
}

.profile-link {
    display: block;
    transition: var(--transition);
    border-radius: 50%;
}

.profile-link:hover {
    transform: scale(1.05);
}

.profile-image {
    width: 250px;
    height: 250px;
    border-radius: 50%;
    object-fit: cover;
    transition: var(--transition);
}

@media (min-width: 768px) {
    .profile-image {
        width: 300px;
        height: 300px;
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 0.95rem;
}

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

.btn-primary:hover {
    background-color: #1d4ed8;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

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

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

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 300;
    margin-bottom: var(--spacing-md);
}

.section-header p {
    font-size: 1rem;
    color: var(--color-text-light);
}

/* About Section */
.about {
    background-color: var(--color-surface);
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
}

.project-card {
    background-color: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    text-decoration: none;
    color: inherit;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.project-image {
    aspect-ratio: 16/10;
    overflow: hidden;
    background-color: var(--color-surface);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-content {
    padding: var(--spacing-md);
}

.project-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.project-content p {
    color: var(--color-text-light);
    font-size: 0.95rem;
}

/* About Detail Page */
.about-detail {
    padding: var(--spacing-2xl) 0;
    min-height: 70vh;
}

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

@media (min-width: 768px) {
    .about-content {
        grid-template-columns: 2fr 1fr;
        gap: var(--spacing-2xl);
    }
}

.about-content-centered {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xl);
}

.about-image-main {
    display: flex;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
}

.portrait-image-large {
    width: 250px;
    height: 250px;
    border-radius: 50%;
    object-fit: cover;
}

@media (min-width: 768px) {
    .portrait-image-large {
        width: 280px;
        height: 280px;
    }
}

.about-text-centered {
    max-width: 700px;
    text-align: left;
}

.about-title-centered {
    font-size: 1.8rem;
    font-weight: 300;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    line-height: 1;
    text-align: left;
}

@media (min-width: 768px) {
    .about-title-centered {
        font-size: 1.8rem;
    }
}

.about-description-centered {
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text);
}

.about-description-centered p {
    margin-bottom: var(--spacing-sm);
}


.about-title {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
    line-height: 1.2;
}

@media (min-width: 768px) {
    .about-title {
        font-size: 3rem;
    }
}

.about-description {
    font-size: 1.125rem;
    line-height: 1.7;
    color: var(--color-text);
}

.about-description p {
    margin-bottom: var(--spacing-md);
}

.fun-facts {
    margin: var(--spacing-lg) 0;
    padding: var(--spacing-lg);
    background-color: var(--color-surface);
    border-radius: var(--border-radius);
}

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

.fact:last-child {
    margin-bottom: 0;
}

.fact-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.fact-text {
    font-size: 1rem;
    color: var(--color-text);
    line-height: 1.6;
}

.about-image {
    display: flex;
    justify-content: center;
}

.portrait-image {
    width: 100%;
    max-width: 400px;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

@media (min-width: 768px) {
    .portrait-image {
        max-width: 300px;
    }
}

/* Contact Section */
.contact {
    background-color: var(--color-surface);
}

.contact-content {
    text-align: center;
}

.contact-email {
    display: inline-block;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-primary);
    text-decoration: none;
    margin-bottom: var(--spacing-lg);
    transition: var(--transition);
}

.contact-email:hover {
    color: #1d4ed8;
}

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

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: white;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.social-link:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.social-link img {
    width: 24px;
    height: 24px;
    object-fit: contain;
}

/* Project Detail Pages */
.project-detail {
    padding: var(--spacing-2xl) 0;
    max-width: 100%;
}

.back-nav {
    margin-bottom: var(--spacing-lg);
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: var(--spacing-lg);
}

.back-link {
    color: var(--color-text-light);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.back-link:hover {
    color: var(--color-primary);
}

.project-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.project-title {
    font-size: 3rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

@media (min-width: 768px) {
    .project-title {
        font-size: 4rem;
    }
}

.project-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xl);
}

.project-link {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
}

.project-link:hover {
    text-decoration: underline;
}

.project-hero-image {
    margin-bottom: var(--spacing-lg);
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image {
    width: auto;
    max-width: 600px;
    max-height: 400px;
    height: auto;
    border-radius: var(--border-radius);
    object-fit: contain;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.1));
}

.project-content {
    max-width: 900px;
    margin: 0 auto;
    width: 100%;
}

.content-section {
    margin-bottom: 1rem;
    padding: 0;
}

.content-section h2 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    margin-top: 0;
    color: var(--color-text);
}

.content-section p {
    font-size: 1.125rem;
    line-height: 1.6;
    color: var(--color-text);
    margin-bottom: 0.5rem;
    margin-top: 0;
}

.content-image {
    margin: 0.75rem 0;
    text-align: center;
}

.section-image {
    width: 100%;
    max-width: 600px;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    margin-bottom: 0.5rem;
}

.image-caption {
    font-size: 0.95rem;
    color: var(--color-text-light);
    font-style: italic;
    margin-bottom: 0;
}

.project-nav-footer {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

/* Code Blocks */
.code-block {
    margin: 0.75rem 0;
    background-color: var(--color-surface);
    border-radius: var(--border-radius);
    padding: 0.75rem;
}

.code-block p {
    margin-bottom: 0.5rem;
    margin-top: 0;
    font-weight: 500;
}

.code-block pre {
    background-color: #f1f5f9;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    padding: var(--spacing-sm);
    overflow-x: auto;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.9rem;
    line-height: 1.4;
}

.code-block code {
    color: var(--color-text);
}

/* User Stories */
.user-stories {
    margin: 0.75rem 0;
}

.user-story {
    background-color: var(--color-surface);
    border-left: 4px solid var(--color-primary);
    padding: 0.5rem 0.75rem;
    margin-bottom: 0.5rem;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.user-story:last-child {
    margin-bottom: 0;
}

.user-story p {
    margin-bottom: 0;
    font-size: 1rem;
    line-height: 1.6;
}

/* Project Links */
.project-links {
    margin-top: var(--spacing-md);
    text-align: center;
}

.content-section ul {
    margin: 0.5rem 0;
    padding-left: var(--spacing-lg);
}

.content-section ul li {
    margin-bottom: 0.25rem;
    color: var(--color-text);
    font-size: 1.125rem;
    line-height: 1.6;
}

.content-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 1rem;
    margin-bottom: 0.5rem;
    color: var(--color-text);
}

.content-section pre {
    background-color: var(--color-surface);
    border-radius: var(--border-radius);
    padding: var(--spacing-sm);
    margin: 0.5rem 0;
    font-size: 0.95rem;
    line-height: 1.6;
    overflow-x: auto;
}

/* Research Questions */
.research-questions {
    margin: 0.5rem 0;
}

.question-block {
    background-color: var(--color-surface);
    border-radius: var(--border-radius);
    padding: 0.75rem;
    margin-bottom: 0.75rem;
    border-left: 4px solid var(--color-primary);
}

.question-block:last-child {
    margin-bottom: 0;
}

.question-block h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    margin-top: 0;
    color: var(--color-text);
}

.question-block ul {
    margin: 0;
    padding-left: var(--spacing-lg);
}

.question-block ul li {
    margin-bottom: var(--spacing-xs);
    color: var(--color-text);
}

/* Data Info */
.data-info {
    background-color: var(--color-surface);
    border-radius: var(--border-radius);
    padding: 0.75rem;
    margin: 0.75rem 0;
}

.data-info ul {
    margin: 0;
    padding-left: var(--spacing-lg);
}

.data-info ul li {
    margin-bottom: var(--spacing-xs);
    color: var(--color-text);
}

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

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.footer-text {
    margin: 0;
    color: var(--color-text-light);
    font-size: 1rem;
}

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

/* Responsive Design */
@media (max-width: 767px) {
    .nav-links {
        gap: var(--spacing-md);
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 200px;
        justify-content: center;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .social-links {
        gap: var(--spacing-sm);
    }
    
    /* Project pages mobile adjustments */
    .project-title {
        font-size: 2.5rem;
    }
    
    .project-content,
    .project-header,
    .back-nav,
    .project-nav-footer {
        max-width: 100%;
        padding-left: var(--spacing-md);
        padding-right: var(--spacing-md);
    }
    
    .content-section h2 {
        font-size: 1.75rem;
    }
    
    .question-block h3 {
        font-size: 1.125rem;
    }
}

/* Smooth Animations */
@media (prefers-reduced-motion: no-preference) {
    * {
        transition: var(--transition);
    }
}

/* Focus States for Accessibility */
.nav-link:focus,
.btn:focus,
.contact-email:focus,
.social-link:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .nav,
    .hero-actions,
    .social-links {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.4;
    }
    
    .hero-title {
        font-size: 24pt;
    }
    
    .section-header h2 {
        font-size: 18pt;
    }
}