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

:root {
    /* Color Palette */
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --background: #ffffff;
    --background-alt: #f8fafc;
    --background-dark: #0f172a;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Spacing */
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-12: 3rem;
    --spacing-16: 4rem;
    --spacing-20: 5rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-4);
}

/* Progress Banner */
.progress-banner {
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: white;
    text-align: center;
    padding: var(--spacing-2) 0;
    font-size: var(--font-size-sm);
    font-weight: 500;
    position: relative;
    overflow: hidden;
}

.progress-banner::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0% { left: -100%; }
    100% { left: 100%; }
}

.progress-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-2);
}

.progress-content i {
    font-size: 1rem;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-4);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo a {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.nav-menu {
    display: flex;
    gap: var(--spacing-8);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
}

/* Modern Language Toggle */
.language-toggle {
    display: flex;
    background: var(--background-alt);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2px;
    position: relative;
    overflow: hidden;
}

.language-toggle::before {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: calc(50% - 2px);
    height: calc(100% - 4px);
    background: var(--primary-color);
    border-radius: var(--radius-md);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1;
}

.language-toggle[data-active="es"]::before {
    transform: translateX(100%);
}

.lang-btn {
    position: relative;
    z-index: 2;
    background: transparent;
    border: none;
    padding: var(--spacing-2) var(--spacing-3);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    gap: var(--spacing-1);
    border-radius: var(--radius-md);
    min-width: 60px;
    justify-content: center;
}

.lang-btn:hover {
    color: var(--text-primary);
    transform: translateY(-1px);
}

.lang-btn.active {
    color: white;
    font-weight: 600;
}

.lang-btn .flag {
    font-size: 1rem;
    line-height: 1;
}

.lang-btn .lang-text {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

/* Hover effect for the entire toggle */
.language-toggle:hover {
    border-color: var(--primary-color);
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.15);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    min-height: 80vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--background-alt) 0%, var(--background) 100%);
    padding: 120px 0 var(--spacing-16) 0;
}

.hero-container {
    width: 100%;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-16);
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-4);
}

.hero-title {
    font-size: var(--font-size-5xl);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: var(--spacing-6);
    color: var(--text-primary);
}

.highlight {
    color: var(--primary-color);
    position: relative;
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-3);
    font-weight: 500;
}

.hero-role {
    margin-bottom: var(--spacing-4);
}

.role-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: var(--spacing-1) var(--spacing-3);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-sm);
    font-weight: 600;
    letter-spacing: 0.3px;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.hero-location {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
    margin-bottom: var(--spacing-6);
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    font-weight: 500;
}

.hero-location .flag {
    font-size: var(--font-size-xl);
    line-height: 1;
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-8);
    line-height: 1.7;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-4);
    flex-wrap: wrap;
}

.profile-img {
    width: 100%;
    max-width: 400px;
    height: auto;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    transition: transform 0.3s ease;
}

.profile-img:hover {
    transform: translateY(-5px);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-2);
    padding: var(--spacing-3) var(--spacing-6);
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    font-size: var(--font-size-base);
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
}

.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);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border-color: var(--border-color);
    font-size: var(--font-size-sm);
    padding: var(--spacing-2) var(--spacing-4);
}

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

/* Section Styles */
section {
    padding: var(--spacing-20) 0;
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-16);
    color: var(--text-primary);
    position: relative;
}

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

/* About Section */
.about {
    background: var(--background-alt);
    padding: var(--spacing-16) 0;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-16);
    align-items: start;
}

.about-text p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-6);
    line-height: 1.7;
}

.skills {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-8);
}

.skill-category h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-4);
    color: var(--text-primary);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-2);
}

.skill-tag {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-2) var(--spacing-4);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

/* Disabled Elements */
.projects-disabled .project-card {
    opacity: 0.6;
    pointer-events: none;
    position: relative;
}

.projects-disabled .project-card::after {
    content: 'Coming Soon';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: var(--spacing-2) var(--spacing-4);
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: var(--font-size-sm);
    z-index: 10;
}

.publication-item.disabled {
    opacity: 0.6;
    pointer-events: none;
}

.publication-link.disabled {
    color: var(--text-secondary);
    text-decoration: none;
    cursor: default;
}


.btn.disabled {
    opacity: 0.6;
    cursor: not-allowed;
    pointer-events: none;
    background: var(--text-secondary);
    border-color: var(--text-secondary);
}

/* Projects Section */
.project-category {
    margin-bottom: var(--spacing-16);
}

.category-title {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-8);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.category-title i {
    color: var(--primary-color);
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-8);
}

.project-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

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

.project-image {
    height: 200px;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

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

.project-content {
    padding: var(--spacing-6);
}

.project-content h4 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-3);
    color: var(--text-primary);
}

.project-content p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-4);
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-2);
    margin-bottom: var(--spacing-4);
}

.tech-tag {
    background: var(--background-alt);
    color: var(--text-secondary);
    padding: var(--spacing-1) var(--spacing-3);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: var(--spacing-3);
    flex-wrap: wrap;
}

/* Research Section */
.research {
    background: var(--background-alt);
}

.research-intro {
    max-width: 800px;
    margin: 0 auto var(--spacing-16);
    text-align: center;
}

.research-intro p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    line-height: 1.7;
}

.research-areas {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-8);
    margin-bottom: var(--spacing-16);
}

.research-card {
    background: white;
    padding: var(--spacing-8);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

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

.research-icon {
    width: 80px;
    height: 80px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-4);
}

.research-icon i {
    font-size: var(--font-size-2xl);
    color: white;
}

.research-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-3);
    color: var(--text-primary);
}

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

/* Interest Badges - Discreet Design */
.interest-badges {
    display: flex;
    justify-content: center;
    gap: var(--spacing-3);
    margin-bottom: var(--spacing-16);
    flex-wrap: wrap;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.interest-badge {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2) var(--spacing-3);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--text-secondary);
    transition: all 0.3s ease;
    cursor: default;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    white-space: nowrap;
}

.interest-badge:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.15);
}

.interest-badge i {
    font-size: var(--font-size-base);
    color: var(--primary-color);
    opacity: 0.8;
}

.interest-badge span {
    font-weight: 500;
    letter-spacing: 0.3px;
}

.publications h3 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-6);
    color: var(--text-primary);
}

.publication-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
}

.publication-item {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
    padding: var(--spacing-4);
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.publication-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.publication-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    flex-wrap: wrap;
}

.publication-tag {
    background: var(--accent-color);
    color: white;
    padding: var(--spacing-1) var(--spacing-3);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
    font-weight: 600;
    white-space: nowrap;
}

.publication-date {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-1);
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.publication-date .flag {
    font-size: 1em;
}

.publication-link {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    display: block;
    margin-top: var(--spacing-1);
}

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

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-16);
    align-items: start;
}

.contact-info h3 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-4);
    color: var(--text-primary);
}

.contact-info p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-8);
    line-height: 1.7;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.contact-item i {
    width: 20px;
    color: var(--primary-color);
}

.contact-item a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.contact-cta {
    background: var(--background-alt);
    padding: var(--spacing-8);
    border-radius: var(--radius-lg);
    text-align: center;
}

.contact-cta h4 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-3);
    color: var(--text-primary);
}

.contact-cta p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-6);
}

/* Footer */
.footer {
    background: var(--background-dark);
    color: white;
    padding: var(--spacing-8) 0;
}

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

.footer-content p {
    margin-bottom: var(--spacing-2);
    color: var(--text-light);
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: var(--spacing-8) 0;
    }

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

    .nav-menu a {
        padding: var(--spacing-4);
        display: block;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .hero {
        min-height: 70vh;
        padding: 100px 0 var(--spacing-12) 0;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--spacing-8);
    }
    
    .about {
        padding: var(--spacing-12) 0;
    }

    .hero-title {
        font-size: var(--font-size-4xl);
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-8);
    }

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

    .research-areas {
        grid-template-columns: 1fr;
    }
    
    .interest-badges {
        gap: var(--spacing-2);
        justify-content: center;
    }
    
    .interest-badge {
        padding: var(--spacing-2) var(--spacing-3);
        font-size: var(--font-size-xs);
    }
    
    .interest-badge i {
        font-size: var(--font-size-sm);
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-8);
    }

    .publication-item {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-2);
    }

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

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-3);
    }

    .hero-title {
        font-size: var(--font-size-3xl);
    }

    .section-title {
        font-size: var(--font-size-3xl);
    }

    .btn {
        padding: var(--spacing-2) var(--spacing-4);
        font-size: var(--font-size-sm);
    }
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

/* Focus styles for accessibility */
.btn:focus,
.nav-link:focus,
.publication-link:focus,
.contact-item a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Loading animation for images */
.project-image img,
.profile-img {
    opacity: 0;
    animation: fadeIn 0.6s ease-in-out forwards;
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

/* Certifications Section */
.certifications {
    background: var(--background-alt);
}

.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-8);
}

.cert-card {
    background: white;
    padding: var(--spacing-8);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    text-align: center;
}

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

.cert-icon {
    width: 80px;
    height: 80px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-4);
}

.cert-icon i {
    font-size: var(--font-size-3xl);
    color: white;
}

.cert-content h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-2);
    color: var(--text-primary);
}

.cert-issuer {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: var(--spacing-1);
}

.cert-date {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-4);
}

.cert-desc {
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

/* Testimonials Section */
.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-8);
}

.testimonial-card {
    background: white;
    padding: var(--spacing-8);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

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

.testimonial-content {
    margin-bottom: var(--spacing-6);
}

.quote-icon {
    color: var(--primary-color);
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-4);
}

.testimonial-content p {
    font-style: italic;
    color: var(--text-secondary);
    line-height: 1.7;
    margin: 0;
    font-size: 1.125rem;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
}

.author-avatar {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--border-color);
}

.author-info h4 {
    margin: 0 0 var(--spacing-1) 0;
    color: var(--text-primary);
    font-size: 1.125rem;
}

.author-info p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Timeline Section */
.timeline {
    background: var(--background-alt);
}

.timeline-container {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

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

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-12);
    padding-left: 80px;
}

.timeline-marker {
    position: absolute;
    left: 20px;
    top: 8px;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    border: 4px solid white;
    box-shadow: 0 0 0 4px var(--primary-color);
}

.timeline-marker.current {
    background: var(--accent-color);
    box-shadow: 0 0 0 4px var(--accent-color);
}

.timeline-content {
    background: white;
    padding: var(--spacing-6);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.timeline-content:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-lg);
}

.timeline-date {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.875rem;
    margin-bottom: var(--spacing-2);
}

.timeline-content h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-1);
    color: var(--text-primary);
}

.timeline-content h4 {
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: var(--spacing-3);
    font-size: 1rem;
}

.timeline-content p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

/* Animation Classes */
.animate-in {
    animation: slideInUp 0.6s ease-out forwards;
}

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

/* Responsive Design Updates */
@media (max-width: 768px) {
    .nav-actions {
        gap: var(--spacing-2);
    }
    
    .language-toggle {
        padding: 1px;
    }
    
    .lang-btn {
        padding: var(--spacing-1) var(--spacing-2);
        min-width: 50px;
        font-size: 0.8rem;
    }
    
    .lang-btn .lang-text {
        font-size: 0.7rem;
    }
    
    .lang-btn .flag {
        font-size: 0.9rem;
    }
    
    .certifications-grid {
        grid-template-columns: 1fr;
    }
    
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline-container::before {
        left: 15px;
    }
    
    .timeline-item {
        padding-left: 50px;
    }
    
    .timeline-marker {
        left: 5px;
        width: 16px;
        height: 16px;
    }
    
    .timeline-content:hover {
        transform: none;
    }
}

@media (max-width: 480px) {
    .nav-menu {
        gap: var(--spacing-4);
    }
    
    .cert-card,
    .testimonial-card {
        padding: var(--spacing-6);
    }
    
    .timeline-item {
        padding-left: 40px;
    }
}