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

:root {
    --primary-color: #000080;
    --secondary-color: #4169E1;
    --accent-color: #1E90FF;
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
    --text-light: #bdc3c7;
    --background-primary: #ffffff;
    --background-secondary: #f8f9fa;
    --background-dark: #2c3e50;
    --border-color: #e9ecef;
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 20px rgba(0, 0, 0, 0.15);
    --shadow-heavy: 0 8px 30px rgba(0, 0, 0, 0.2);
    --gradient-primary: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    --gradient-secondary: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.2;
    color: var(--text-primary);
    background-color: var(--background-primary);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 0.75rem;
}

.section-title {
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 2rem;
    color: var(--primary-color);
    position: relative;
}

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

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

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-light);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-logo a {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

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

.nav-logo-img {
    height: 50px;
    width: 50px;
    margin-right: 12px;
    vertical-align: middle;
    border-radius: 50%;
    object-fit: cover;
    object-position: center;
    display: inline-block;
    border: 2px solid var(--primary-color);
}

.nav-menu {
    display: flex;
    gap: 1.5rem;
}

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

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

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

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

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

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="%23000080" opacity="0.05"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    pointer-events: none;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 1;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}



.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-weight: 500;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.2;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-light);
}

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

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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



.profile-card {
    background: white;
    border-radius: 25px;
    padding: 2.5rem;
    box-shadow: var(--shadow-heavy);
    text-align: center;
    transform: perspective(1000px) rotateY(-3deg);
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 128, 0.1);
}

.profile-card:hover {
    transform: perspective(1000px) rotateY(0deg);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.profile-image {
    position: relative;
    margin-bottom: 2rem;
    display: inline-block;
}

.profile-photo {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid white;
    box-shadow: var(--shadow-medium);
    transition: var(--transition);
}

.profile-card:hover .profile-photo {
    transform: scale(1.05);
    box-shadow: var(--shadow-heavy);
}

.profile-status {
    position: absolute;
    bottom: 10px;
    right: 10px;
    background: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    box-shadow: var(--shadow-light);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-primary);
}

.status-dot {
    width: 8px;
    height: 8px;
    background: #4CAF50;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

.profile-info h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
}

.expertise-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
}

.expertise-tag {
    background: var(--gradient-primary);
    color: white;
    padding: 0.5rem 1.2rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
    transition: var(--transition);
    min-width: 120px;
    text-align: center;
}

.expertise-tag:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-light);
}

/* About Section */
.about {
    padding: 3rem 0;
    background: var(--background-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: start;
}

.lead {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 2rem;
    font-weight: 600;
    line-height: 1.4;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.about-text p {
    margin-bottom: 1.8rem;
    color: var(--text-secondary);
    line-height: 1.4;
    font-size: 1rem;
    text-align: justify;
}

.about-expertise,
.about-experience {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--background-secondary);
    border-radius: 12px;
    border-left: 4px solid var(--primary-color);
}

.about-expertise h3,
.about-experience h3 {
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.about-expertise h3::before {
    content: "🎯";
    font-size: 1.2rem;
}

.about-experience h3::before {
    content: "📊";
    font-size: 1.2rem;
}

.about-expertise p,
.about-experience p {
    margin-bottom: 0;
    color: var(--text-secondary);
    line-height: 1.4;
    font-size: 0.95rem;
}

.about-expertise strong,
.about-experience strong {
    color: var(--primary-color);
    font-weight: 600;
}

.about-highlights {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.highlight-item {
    display: flex;
    align-items: flex-start;
    gap: 1.2rem;
    padding: 1.5rem;
    background: var(--background-secondary);
    border-radius: 12px;
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
}

.highlight-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-light);
}

.highlight-item i {
    font-size: 2rem;
    color: var(--primary-color);
    min-width: 50px;
}

.highlight-item h4 {
    margin-bottom: 0.4rem;
    color: var(--primary-color);
    font-size: 1rem;
    font-weight: 600;
}

.highlight-item p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 0.85rem;
    line-height: 1.3;
}



/* Publications Section */
.publications {
    padding: 3rem 0;
    background: var(--background-primary);
}

.publications-filter {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.filter-btn {
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--primary-color);
    background: transparent;
    color: var(--primary-color);
    border-radius: 25px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--primary-color);
    color: white;
}

.publications-grid {
    display: grid;
    gap: 1.5rem;
}

.publication-item {
    background: white;
    border-radius: 15px;
    padding: 1.5rem;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
}

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

.publication-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.publication-header h3 {
    color: var(--primary-color);
    font-size: 1.2rem;
    line-height: 1.2;
    flex: 1;
    margin-right: 1rem;
}

.publication-year {
    background: var(--gradient-secondary);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
    white-space: nowrap;
}

.publication-authors {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.publication-venue {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-style: italic;
}

.publication-links {
    display: flex;
    gap: 1rem;
}

.publication-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

/* Experience Section */
.experience {
    padding: 3rem 0;
    background: var(--background-secondary);
    position: relative;
}

.experience::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="dots" width="20" height="20" patternUnits="userSpaceOnUse"><circle cx="10" cy="10" r="1" fill="%23000080" opacity="0.03"/></pattern></defs><rect width="100" height="100" fill="url(%23dots)"/></svg>');
    pointer-events: none;
}

.timeline {
    position: relative;
    max-width: 1000px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.timeline-item {
    position: relative;
    margin-bottom: 2rem;
    padding-left: 80px;
}

.timeline-marker {
    position: absolute;
    left: 18px;
    top: 0;
    width: 24px;
    height: 24px;
    background: var(--gradient-primary);
    border-radius: 50%;
    border: 4px solid white;
    box-shadow: var(--shadow-medium);
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.timeline-marker::after {
    content: '';
    position: absolute;
    width: 8px;
    height: 8px;
    background: white;
    border-radius: 50%;
    transition: var(--transition);
}

.timeline-item:hover .timeline-marker {
    transform: scale(1.1);
    box-shadow: var(--shadow-heavy);
}

.timeline-item:hover .timeline-marker::after {
    transform: scale(1.2);
}

.timeline-content {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
    position: relative;
}

.timeline-content::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 20px;
    width: 0;
    height: 0;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    border-right: 8px solid var(--primary-color);
}

.timeline-content:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-heavy);
    border-left-color: var(--secondary-color);
}

.timeline-content:hover::before {
    border-right-color: var(--secondary-color);
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.experience-header h3 {
    color: var(--primary-color);
    font-size: 1.4rem;
    font-weight: 700;
    line-height: 1.3;
    flex: 1;
    min-width: 200px;
}

.experience-period {
    background: var(--gradient-primary);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    white-space: nowrap;
    box-shadow: var(--shadow-light);
}

.timeline-content h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.experience-location {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-style: italic;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.experience-location::before {
    content: '📍';
    font-size: 0.9rem;
}

.experience-achievements {
    list-style: none;
    margin-top: 1rem;
}

.experience-achievements li {
    margin-bottom: 0.6rem;
    color: var(--text-secondary);
    line-height: 1.3;
    position: relative;
    padding-left: 2rem;
    font-size: 0.95rem;
}

.experience-achievements li::before {
    content: '▶';
    color: var(--primary-color);
    font-weight: bold;
    position: absolute;
    left: 0;
    top: 0;
    font-size: 0.8rem;
}

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

/* Add subtle animation to timeline items */
.timeline-item {
    opacity: 0;
    transform: translateX(-30px);
    animation: slideInLeft 0.6s ease-out forwards;
}

.timeline-item:nth-child(1) { animation-delay: 0.1s; }
.timeline-item:nth-child(2) { animation-delay: 0.2s; }
.timeline-item:nth-child(3) { animation-delay: 0.3s; }
.timeline-item:nth-child(4) { animation-delay: 0.4s; }

@keyframes slideInLeft {
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Projects Section */
.projects {
    padding: 5rem 0;
    background: var(--background-primary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.project-card {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    text-align: center;
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-heavy);
}

.project-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.project-icon i {
    font-size: 2rem;
    color: white;
}

.project-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.project-card p {
    color: var(--text-secondary);
    line-height: 1.3;
    margin-bottom: 1.5rem;
}

.project-collaborator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    justify-content: center;
}

.project-collaborator i {
    color: var(--primary-color);
}

/* Achievements Section */
.achievements {
    padding: 2.5rem 0;
    background: var(--background-secondary);
    position: relative;
}

.achievements::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="achievement-dots" width="25" height="25" patternUnits="userSpaceOnUse"><circle cx="12.5" cy="12.5" r="1.5" fill="%23000080" opacity="0.04"/></pattern></defs><rect width="100" height="100" fill="url(%23achievement-dots)"/></svg>');
    pointer-events: none;
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.2rem;
    position: relative;
    z-index: 1;
}

.achievement-card {
    background: white;
    border-radius: 15px;
    padding: 1.2rem;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
    position: relative;
    overflow: hidden;
}

.achievement-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: var(--transition);
}

.achievement-card:hover::before {
    transform: scaleX(1);
}

.achievement-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-heavy);
    border-left-color: var(--secondary-color);
}

.achievement-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    transition: var(--transition);
}

.achievement-card:hover .achievement-icon {
    transform: scale(1.1) rotate(5deg);
    box-shadow: var(--shadow-medium);
}

.achievement-icon i {
    font-size: 1.5rem;
    color: white;
}

.achievement-content h3 {
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.achievement-content p {
    color: var(--text-secondary);
    line-height: 1.2;
    margin-bottom: 0.8rem;
    font-size: 0.85rem;
}

.achievement-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
}

.tag {
    background: var(--background-secondary);
    color: var(--primary-color);
    padding: 0.3rem 0.6rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

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

/* Education Section */
.education {
    padding: 3rem 0;
    background: var(--background-primary);
}

.education-timeline {
    max-width: 800px;
    margin: 0 auto;
}

.education-item {
    background: white;
    border-radius: 15px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
}

.education-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.education-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.education-header h3 {
    color: var(--primary-color);
    font-size: 1.3rem;
}

.education-gpa {
    background: var(--gradient-primary);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: 0.9rem;
    font-weight: 600;
}

.education-item h4 {
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

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

.education-period {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-weight: 500;
}

.education-courses h5 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.education-courses p {
    color: var(--text-secondary);
    line-height: 1.3;
}

/* Certifications Section */
.certifications {
    padding: 2.5rem 0;
    background: var(--background-primary);
}

.certifications::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.2rem;
    margin-top: 1.5rem;
}

.certification-item {
    background: white;
    border-radius: 12px;
    padding: 1.2rem;
    box-shadow: var(--shadow-light);
    transition: all 0.3s ease;
    border: 1px solid rgba(120, 119, 198, 0.1);
    position: relative;
    overflow: hidden;
}

.certification-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.certification-item:hover::before {
    transform: scaleX(1);
}

.certification-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.certification-header {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.certification-icon {
    width: 50px;
    height: 50px;
    border-radius: 10px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    box-shadow: var(--shadow-light);
}

.certification-icon i {
    font-size: 1.2rem;
    color: white;
}

.certification-info h3 {
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    font-size: 1rem;
    line-height: 1.3;
}

.certification-issuer {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.9rem;
    margin: 0;
}

.certification-details {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    margin-bottom: 1rem;
}

.certification-date,
.certification-id {
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 500;
}

.certification-verify {
    margin-top: auto;
}

.verify-link {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.85rem;
    transition: all 0.3s ease;
}

.verify-link:hover {
    color: var(--secondary-color);
    transform: translateX(5px);
}

.verify-link i {
    font-size: 0.8rem;
}

/* Responsive Design for Certifications */
@media (max-width: 768px) {
    .certifications {
        padding: 2rem 0;
    }
    
    .certifications-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
        margin-top: 1.5rem;
    }
    
    .certification-item {
        padding: 1.25rem;
    }
    
    .certification-header {
        gap: 0.5rem;
    }
    
    .certification-icon {
        width: 45px;
        height: 45px;
    }
    
    .certification-icon i {
        font-size: 1.1rem;
    }
}

@media (max-width: 480px) {
    .certification-item {
        padding: 1rem;
    }
    
    .certification-info h3 {
        font-size: 0.95rem;
    }
    
    .certification-issuer {
        font-size: 0.85rem;
    }
}

/* Contact Section */
.contact {
    padding: 3rem 0;
    background: var(--background-secondary);
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.contact-header {
    margin-bottom: 2rem;
}

.contact-header h3 {
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    font-size: 1.6rem;
}

.contact-header p {
    color: var(--text-secondary);
    line-height: 1.3;
    font-size: 1rem;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.2rem;
    max-width: 700px;
    margin: 0 auto;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    text-align: left;
    min-height: 80px;
}

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

.contact-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
    min-width: 30px;
}

.contact-item h4 {
    color: var(--primary-color);
    margin-bottom: 0.25rem;
    font-size: 1rem;
}

.contact-item a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
}

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

.contact-additional {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: var(--shadow-light);
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-description h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.contact-description p {
    color: var(--text-secondary);
    line-height: 1.2;
    font-size: 0.95rem;
}

.contact-location {
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.contact-location h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.contact-location p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.contact-location p:last-child {
    font-style: italic;
    color: var(--text-light);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 0, 128, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* CAPTCHA Styles */
.captcha-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.captcha-container label {
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    display: block;
    width: 100%;
}

.captcha-container input {
    flex: 1;
    min-width: 120px;
    max-width: 150px;
}

.btn-refresh {
    background: var(--secondary-color);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 0.75rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 48px;
}

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

.btn-refresh i {
    font-size: 1rem;
}

#captcha-question {
    font-weight: 600;
    color: var(--primary-color);
    background: var(--background-secondary);
    padding: 0.25rem 0.5rem;
    border-radius: 5px;
    display: inline-block;
    margin: 0 0.5rem;
}

/* Footer */
.footer {
    background: var(--background-dark);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-links {
    display: flex;
    gap: 1rem;
}

.footer-links a {
    color: white;
    font-size: 1.5rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--accent-color);
    transform: translateY(-3px);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 60px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-light);
        padding: 1.5rem 0;
    }

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

    .nav-toggle {
        display: flex;
    }

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

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

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

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

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

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

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .profile-photo {
        width: 150px;
        height: 150px;
    }

    .profile-card {
        padding: 2rem;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
        max-width: 400px;
    }

    .contact-header h3 {
        font-size: 1.5rem;
    }

    .contact-header p {
        font-size: 1rem;
    }

    .contact-item {
        padding: 1.25rem;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        padding-left: 60px;
    }

    .timeline-marker {
        left: 8px;
        width: 20px;
        height: 20px;
    }

    .timeline-content {
        padding: 1.5rem;
    }

    .experience-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .experience-header h3 {
        font-size: 1.2rem;
        min-width: auto;
    }

    .experience-period {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }

    .footer-content {
        flex-direction: column;
        gap: 1rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .achievements {
        padding: 1.5rem 0;
    }
    
    .achievements-grid {
        grid-template-columns: 1fr;
        gap: 0.8rem;
    }
    
    .achievement-card {
        padding: 1rem;
    }
    
    .achievement-content h3 {
        font-size: 1.1rem;
    }
    
    .achievement-content p {
        font-size: 0.85rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

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

    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }

    .btn {
        width: 100%;
        max-width: 250px;
    }

    .profile-photo {
        width: 120px;
        height: 120px;
    }

    .profile-card {
        padding: 1.5rem;
    }

    .expertise-tags {
        gap: 0.3rem;
    }

    .expertise-tag {
        font-size: 0.7rem;
        padding: 0.3rem 0.6rem;
    }

    .timeline-content,
    .achievement-card,
    .education-item {
        padding: 1.5rem;
    }

    .contact-header h3 {
        font-size: 1.3rem;
    }

    .contact-header p {
        font-size: 0.9rem;
    }

    .contact-item {
        padding: 1rem;
        gap: 0.8rem;
    }

    .contact-item i {
        font-size: 1.3rem;
    }

    .publication-header {
        flex-direction: column;
        gap: 1rem;
    }

    .publication-header h3 {
        margin-right: 0;
    }
}

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

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

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

.animate-fadeInUp {
    animation: fadeInUp 0.6s ease-out;
}

.animate-fadeInLeft {
    animation: fadeInLeft 0.6s ease-out;
}

.animate-fadeInRight {
    animation: fadeInRight 0.6s ease-out;
}

/* Scroll animations */
.scroll-animate {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease-out;
}

.scroll-animate.animate {
    opacity: 1;
    transform: translateY(0);
}

/* Loading animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}