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

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #ffffff;
    --bg-alt: #f8f9fa;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

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

/* Header and Navigation */
.header {
    background-color: var(--primary-color);
    color: white;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

.navbar {
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.nav-brand h1 {
    font-size: 1.8rem;
    margin-bottom: 0.25rem;
    font-weight: 600;
}

.nav-title {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 300;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    gap: 4px;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: white;
    transition: var(--transition);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 400;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
}

.nav-link:hover {
    opacity: 0.8;
}

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

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

/* Sections */
.section {
    padding: 4rem 0;
}

.section-alt {
    background-color: var(--bg-alt);
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
    font-weight: 600;
    text-align: center;
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--secondary-color);
}

/* About Section */
.about-content {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    align-items: flex-start;
    gap: 3rem;
}

.about-image {
    flex-shrink: 0;
}

.profile-img {
    width: 250px;
    height: 250px;
    border-radius: 50%;
    object-fit: cover;
    box-shadow: var(--shadow);
    border: 4px solid var(--secondary-color);
}

.about-text {
    flex: 1;
}

.about-text p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-light);
    text-align: justify;
}

/* Education Section */
.education-list {
    max-width: 900px;
    margin: 0 auto;
}

.education-item {
    background-color: white;
    padding: 2rem;
    margin-bottom: 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.education-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.education-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 0.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.education-header h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 600;
}

.education-date {
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 500;
}

.education-institution {
    font-size: 1.2rem;
    color: var(--secondary-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.education-details {
    color: var(--text-light);
    line-height: 1.6;
}

/* Experience Section */
.experience-list {
    max-width: 900px;
    margin: 0 auto;
}

.experience-item {
    background-color: white;
    padding: 2rem;
    margin-bottom: 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.experience-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 0.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.experience-header h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 600;
}

.experience-date {
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 500;
}

.experience-institution {
    font-size: 1.2rem;
    color: var(--secondary-color);
    font-weight: 500;
    margin-bottom: 0.75rem;
}

.experience-description {
    color: var(--text-light);
    line-height: 1.8;
}

/* Skills Section */
.skills-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.skills-category {
    background-color: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.skills-category h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 600;
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

.skills-list {
    list-style: none;
}

.skills-list li {
    padding: 0.75rem 0;
    color: var(--text-light);
    border-bottom: 1px solid var(--border-color);
    position: relative;
    padding-left: 1.5rem;
}

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

.skills-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
}

/* Research Section */
.research-content {
    max-width: 1000px;
    margin: 0 auto;
}

.research-categories {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.research-category {
    background-color: white;
    padding: 2.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.research-category h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-weight: 600;
    border-bottom: 3px solid var(--secondary-color);
    padding-bottom: 0.75rem;
}

.publications-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.publication-item {
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.publication-item:last-child {
    border-bottom: none;
}

.publication-item:hover {
    padding-left: 0.5rem;
}

.publication-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.publication-authors {
    font-size: 0.95rem;
    color: var(--text-light);
    margin-bottom: 0.4rem;
    font-style: italic;
}

.publication-venue {
    font-size: 0.95rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.publication-links {
    margin-top: 0.5rem;
}

.publication-links a {
    color: var(--secondary-color);
    text-decoration: none;
    font-size: 0.9rem;
    margin-right: 1rem;
    transition: var(--transition);
    padding: 0.25rem 0.5rem;
    border: 1px solid var(--secondary-color);
    border-radius: 3px;
    display: inline-block;
}

.publication-links a:hover {
    background-color: var(--secondary-color);
    color: white;
    transform: translateY(-1px);
}

.research-footer {
    margin-top: 3rem;
    text-align: center;
    font-size: 1rem;
    color: var(--text-light);
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

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

.research-footer a:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

/* CV Section */
.cv-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.cv-description {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-light);
    margin-bottom: 2rem;
}

.cv-download {
    margin-top: 2rem;
}

.cv-link {
    display: inline-block;
    padding: 1rem 2.5rem;
    background-color: var(--secondary-color);
    color: white;
    text-decoration: none;
    border-radius: 5px;
    font-size: 1.1rem;
    font-weight: 500;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.cv-link:hover {
    background-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.cv-link-text {
    display: inline-block;
}

/* Contact Section */
.contact-content {
    max-width: 800px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 3rem;
}

.contact-info p {
    margin-bottom: 1rem;
    font-size: 1.05rem;
    line-height: 1.8;
}

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

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

.contact-links h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 600;
}

.profile-links {
    list-style: none;
}

.profile-links li {
    margin-bottom: 0.75rem;
}

.profile-links a {
    color: var(--secondary-color);
    text-decoration: none;
    font-size: 1.05rem;
    transition: var(--transition);
    display: inline-block;
}

.profile-links a:hover {
    color: var(--primary-color);
    transform: translateX(5px);
}

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

.footer p {
    opacity: 0.9;
}

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

    .nav-menu {
        display: none;
        width: 100%;
        flex-direction: column;
        gap: 0;
        margin-top: 1rem;
        padding-top: 1rem;
        border-top: 1px solid rgba(255, 255, 255, 0.2);
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-menu li {
        width: 100%;
    }

    .nav-link {
        display: block;
        padding: 1rem 0;
        width: 100%;
    }

    .section {
        padding: 3rem 0;
    }

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

    .education-header,
    .experience-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .education-date,
    .experience-date {
        margin-top: 0.5rem;
    }

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

    .about-content {
        flex-direction: column;
        align-items: center;
        gap: 2rem;
    }

    .profile-img {
        width: 200px;
        height: 200px;
    }

    .research-category {
        padding: 1.5rem;
    }

    .publication-item {
        padding: 1.25rem 0;
    }

    .publication-title {
        font-size: 1rem;
    }

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

    .about-text p {
        text-align: left;
    }
}

@media (max-width: 480px) {
    .nav-brand h1 {
        font-size: 1.5rem;
    }

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

    .education-item,
    .experience-item {
        padding: 1.5rem;
    }

    .skills-category {
        padding: 1.5rem;
    }

    .profile-img {
        width: 180px;
        height: 180px;
    }

    .research-category {
        padding: 1.25rem;
    }

    .publication-item {
        padding: 1rem 0;
    }

    .publication-title {
        font-size: 0.95rem;
    }

    .publication-authors,
    .publication-venue {
        font-size: 0.9rem;
    }

    .cv-link {
        padding: 0.875rem 2rem;
        font-size: 1rem;
    }
}

/* Print Styles */
@media print {
    .header {
        position: static;
    }

    .menu-toggle {
        display: none;
    }

    .nav-menu {
        display: none;
    }

    .section {
        page-break-inside: avoid;
        padding: 1.5rem 0;
    }

    .footer {
        margin-top: 1rem;
        padding: 1rem 0;
    }

    a {
        color: var(--text-color);
        text-decoration: underline;
    }

    .education-item,
    .experience-item,
    .skills-category {
        box-shadow: none;
        border: 1px solid var(--border-color);
        page-break-inside: avoid;
    }
}