/* CSS Custom Properties */
:root {
    --primary-color: #0d47a1;
    --primary-dark: #002171;
    --secondary-color: #f0f2f5;
    --text-dark: #222222;
    --text-light: #555555;
    --text-muted: #6e6e6e;
    --white: #fff;
    --shadow-light: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 8px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
    --border-radius-small: 4px;
    --transition-smooth: 0.3s ease;
    --max-width: 800px;
    --max-width-desktop: 1000px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
}

/* Mobile-first CSS Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--white);
    padding: 0 var(--spacing-sm);
    font-display: swap;
}

/* Header Styles */
header {
    background: var(--primary-color);
    color: var(--white);
    text-align: center;
    padding: var(--spacing-md) 0;
    margin: 0 calc(-1 * var(--spacing-sm));
    box-shadow: var(--shadow-medium);
}

header h1 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    text-shadow: none;
}

.subtitle {
    font-size: 1rem;
    font-weight: 300;
    opacity: 0.9;
    margin: 0;
}

/* Navigation Styles */
nav {
    background-color: var(--primary-dark);
    padding: var(--spacing-sm) 0;
    text-align: center;
    margin: 0 calc(-1 * var(--spacing-sm));
    box-shadow: var(--shadow-light);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    margin: 0 var(--spacing-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius-small);
    transition: all var(--transition-smooth);
    display: inline-block;
}

nav a:hover,
nav a:focus {
    background-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
    outline: 2px solid rgba(255, 255, 255, 0.3);
    outline-offset: 2px;
}

nav a[aria-current="page"] {
    background-color: rgba(255, 255, 255, 0.3);
    font-weight: 600;
}

/* Language Switcher */
.lang-switcher {
    float: right;
    margin-top: -2rem;
    margin-right: var(--spacing-sm);
}

.lang-switcher a {
    font-size: 0.9rem;
    margin: 0 0.25rem;
    padding: 0.25rem 0.5rem;
}

.lang-switcher .lang-active {
    background-color: rgba(255, 255, 255, 0.3);
    font-weight: 600;
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--primary-color);
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 1000;
    transition: top 0.3s;
}

.skip-link:focus {
    top: 6px;
}

/* Main Content Styles */
main {
    max-width: var(--max-width);
    margin: var(--spacing-lg) auto;
    padding: 0 var(--spacing-sm);
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

main section {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid #eee;
    animation: fadeInUp 0.6s ease-out backwards;
}

main section:nth-child(2) { animation-delay: 0.1s; }
main section:nth-child(3) { animation-delay: 0.2s; }
main section:nth-child(4) { animation-delay: 0.3s; }
main section:nth-child(5) { animation-delay: 0.4s; }

main section:last-child {
    border-bottom: none;
}

main h2 {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: var(--spacing-xs);
    position: relative;
}

main h2::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-dark);
    transition: width var(--transition-smooth);
}

main h2:hover::after {
    width: 100%;
}

main h3 {
    color: var(--primary-dark);
    font-size: 1.3rem;
    margin: var(--spacing-md) 0 var(--spacing-xs) 0;
}

main p {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-sm);
    text-align: justify;
    line-height: 1.7;
}

.profile-photo {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    box-shadow: var(--shadow-medium);
    margin: var(--spacing-sm) auto;
    display: block;
    transition: transform var(--transition-smooth);
    object-fit: cover;
}

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

.skills-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xs);
    margin: var(--spacing-sm) 0;
}

.skills-list li {
    background-color: var(--secondary-color);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-left: 3px solid var(--primary-color);
    font-weight: 500;
    transition: all var(--transition-smooth);
    border-radius: 0 var(--border-radius-small) var(--border-radius-small) 0;
}

.skills-list li:hover {
    background-color: var(--primary-color);
    color: var(--white);
    transform: translateX(5px);
}

.experience-item, .education-item {
    background-color: var(--secondary-color);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-md);
    border-left: 4px solid var(--primary-color);
    transition: all var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.experience-item::before, .education-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 0;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(13, 71, 161, 0.1));
    transition: width var(--transition-smooth);
}

.experience-item:hover::before, .education-item:hover::before {
    width: 100%;
}

.experience-item:hover, .education-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.role-details, .degree-details {
    color: var(--text-light);
    font-style: italic;
    margin-bottom: var(--spacing-xs);
}

.contact-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin: var(--spacing-md) 0;
    justify-content: center;
}

.contact-link {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: var(--spacing-xs) var(--spacing-md);
    text-decoration: none;
    border-radius: var(--border-radius-small);
    font-weight: 500;
    transition: all var(--transition-smooth);
    box-shadow: var(--shadow-light);
    position: relative;
    overflow: hidden;
}

.contact-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.contact-link:hover::before {
    left: 100%;
}

.contact-link:hover,
.contact-link:focus {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.contact-note {
    font-size: 0.9rem;
    color: var(--text-light);
    font-style: italic;
    text-align: center;
}

/* Footer Styles */
footer {
    background: linear-gradient(135deg, #333 0%, #222 100%);
    color: var(--text-muted);
    text-align: center;
    padding: var(--spacing-lg) 0;
    margin: var(--spacing-lg) calc(-1 * var(--spacing-sm)) 0;
}

footer p {
    font-size: 0.9rem;
}

/* Responsive Design - Tablet and larger */
@media (min-width: 768px) {
    body {
        padding: 0 var(--spacing-lg);
    }
    
    header {
        margin: 0 calc(-1 * var(--spacing-lg));
    }
    
    nav {
        margin: 0 calc(-1 * var(--spacing-lg));
    }
    
    header h1 {
        font-size: 2.2rem;
    }
    
    nav a {
        margin: 0 var(--spacing-sm);
        padding: 0.75rem 1.2rem;
        font-size: 0.95rem;
    }
    
    main {
        padding: 0 var(--spacing-lg);
    }
    
    main h2 {
        font-size: 2rem;
    }
    
    .skills-list {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-links {
        justify-content: center;
    }
    
    footer {
        margin: var(--spacing-lg) calc(-1 * var(--spacing-lg)) 0;
    }
}

/* Responsive Design - Desktop */
@media (min-width: 1024px) {
    body {
        padding: 0;
    }
    
    header {
        margin: 0;
    }
    
    nav {
        margin: 0;
    }
    
    header h1 {
        font-size: 2.5rem;
    }
    
    nav a {
        margin: 0 var(--spacing-md);
        padding: 0.75rem var(--spacing-md);
    }
    
    main {
        max-width: var(--max-width-desktop);
        padding: 0 var(--spacing-lg);
    }
    
    main p {
        font-size: 1.2rem;
    }
    
    main h2 {
        font-size: 2.2rem;
    }
    
    .skills-list {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .profile-photo {
        width: 250px;
        height: 250px;
    }
    
    footer {
        margin: var(--spacing-lg) 0 0;
    }
}

/* Accessibility and Performance Enhancements */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --white: #1a1a1a;
        --text-dark: #e0e0e0;
        --text-light: #b0b0b0;
        --text-muted: #888;
        --secondary-color: #2a2a2a;
        --shadow-light: 0 2px 4px rgba(255, 255, 255, 0.1);
        --shadow-medium: 0 4px 8px rgba(255, 255, 255, 0.1);
    }
    
    .experience-item::before, .education-item::before {
        background: linear-gradient(90deg, transparent, rgba(13, 71, 161, 0.2));
    }
}

/* Print styles */
@media print {
    nav,
    .contact-links {
        display: none;
    }
    
    body {
        padding: 0;
        font-size: 12pt;
        line-height: 1.4;
    }
    
    header {
        background: none !important;
        color: black !important;
        margin: 0;
        box-shadow: none;
    }
    
    main {
        max-width: none;
        margin: 0;
        padding: 0;
    }
    
    .profile-photo {
        max-width: 150px;
        max-height: 150px;
    }
    
    footer {
        background: none !important;
        color: black !important;
        margin: 1rem 0 0;
    }
}

/* New v0.1 Component Styles */

/* Hero Section */
.hero {
    text-align: center;
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, rgba(13, 71, 161, 0.05) 0%, rgba(255, 255, 255, 0) 100%);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-xl);
}

.hero-text {
    font-size: 1.2rem;
    margin: var(--spacing-md) 0;
    color: var(--text-light);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    margin: var(--spacing-lg) 0;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    transition: all var(--transition-smooth);
    margin: 0.25rem;
    border: 2px solid transparent;
    cursor: pointer;
}

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

.btn-primary:hover,
.btn-primary:focus {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

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

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

/* Cards Grid */
.overview-cards,
.research-areas,
.expertise-grid,
.resources-grid {
    margin: var(--spacing-xl) 0;
}

.cards-grid,
.research-grid,
.expertise-grid,
.resources-grid {
    display: grid;
    gap: var(--spacing-lg);
    grid-template-columns: 1fr;
}

.card,
.research-item,
.expertise-item,
.resource-item {
    background: white;
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-light);
    transition: all var(--transition-smooth);
    border: 1px solid #f0f0f0;
}

.card:hover,
.research-item:hover,
.expertise-item:hover,
.resource-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
}

.card h3,
.research-item h4,
.expertise-item h4,
.resource-item h4 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.card-link,
.resource-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    display: inline-block;
    margin-top: var(--spacing-sm);
}

.card-link:hover,
.resource-link:hover {
    text-decoration: underline;
}

/* Page Content */
.page-content {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--spacing-lg);
}

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

.page-header h2 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.lead {
    font-size: 1.2rem;
    color: var(--text-light);
    font-weight: 300;
    max-width: 600px;
    margin: 0 auto;
}

/* Bio Section */
.bio-section {
    margin: var(--spacing-xl) 0;
}

.bio-content {
    display: grid;
    gap: var(--spacing-lg);
    align-items: start;
}

.bio-photo {
    width: 100%;
    max-width: 300px;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-medium);
    justify-self: center;
}

.bio-text p {
    margin-bottom: var(--spacing-md);
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: var(--spacing-lg);
}

.timeline::before {
    content: '';
    position: absolute;
    left: 1rem;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary-color);
}

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

.timeline-marker {
    position: absolute;
    left: -2.25rem;
    top: 0.5rem;
    width: 1rem;
    height: 1rem;
    background: var(--primary-color);
    border-radius: 50%;
    border: 3px solid white;
    box-shadow: var(--shadow-light);
}

.timeline-item.current .timeline-marker {
    background: var(--primary-dark);
    box-shadow: 0 0 0 4px rgba(13, 71, 161, 0.2);
}

.timeline-content h4 {
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.organization {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.25rem;
}

.period {
    color: var(--text-light);
    font-style: italic;
    margin-bottom: var(--spacing-sm);
}

.achievements {
    margin-top: var(--spacing-sm);
    padding-left: var(--spacing-md);
}

.achievements li {
    margin-bottom: 0.5rem;
}

/* Contact Styles */
.contact-grid,
.opportunities-grid,
.affiliations-list {
    display: grid;
    gap: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
}

.contact-item,
.opportunity-item,
.affiliation-item {
    padding: var(--spacing-lg);
    border: 1px solid #e0e0e0;
    border-radius: var(--border-radius);
    background: white;
}

.contact-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: var(--secondary-color);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: all var(--transition-smooth);
    margin-top: var(--spacing-sm);
}

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

.contact-link.linkedin:hover {
    background: #0077b5;
}

.contact-link.orcid:hover {
    background: #a6ce39;
}

/* ORCID Badge */
.orcid-info {
    background: var(--secondary-color);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    margin: var(--spacing-lg) 0;
    text-align: center;
}

.orcid-badge {
    margin-bottom: var(--spacing-sm);
}

.orcid-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: #a6ce39;
    text-decoration: none;
    font-weight: 500;
}

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

/* Publications */
.publications-list {
    list-style: none;
    padding: 0;
}

.publications-list li {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid #f0f0f0;
}

.publications-list li:last-child {
    border-bottom: none;
}

/* Research Keywords */
.research-keywords {
    list-style: none;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: var(--spacing-sm);
}

.research-keywords li {
    background: var(--secondary-color);
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.875rem;
    color: var(--text-light);
}

/* Utility Classes */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.loading-message {
    text-align: center;
    padding: var(--spacing-lg);
    color: var(--text-light);
}

.error-message {
    text-align: center;
    padding: var(--spacing-lg);
    color: #d32f2f;
    background: #ffebee;
    border-radius: var(--border-radius);
}

.meta {
    color: var(--text-light);
    font-style: italic;
}

/* Responsive Design Updates */
@media (min-width: 768px) {
    .cards-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .bio-content {
        grid-template-columns: 300px 1fr;
        align-items: start;
    }
    
    .bio-photo {
        justify-self: start;
    }
    
    .contact-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .opportunities-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .lang-switcher {
        float: right;
        margin-top: -3rem;
    }
}

@media (min-width: 1024px) {
    .cards-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .research-grid,
    .expertise-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .opportunities-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .lang-switcher {
        margin-top: -3.5rem;
    }
}