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

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --light-bg: #ecf0f1;
    --text-color: #333;
    --white: #fff;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
}

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

/* Navigation */
.navbar {
    background: var(--primary-color);
    color: var(--white);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

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

.logo {
    font-size: 1.8rem;
    font-weight: bold;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: var(--white);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 100px 20px;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.3rem;
    margin-bottom: 2rem;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    background: var(--accent-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 5px;
    transition: background 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn:hover {
    background: #c0392b;
}

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

.btn-primary:hover {
    background: #2980ca;
}

.cv-download {
    margin: 2rem 0;
}

/* About Section */
.about {
    padding: 80px 20px;
    background: var(--light-bg);
}

.about h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

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

.profile-picture {
    text-align: center;
}

.profile-picture img {
    width: 100%;
    max-width: 300px;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
    border: 3px solid var(--secondary-color);
}

.about-text p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.about p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.skills {
    margin-top: 2rem;
}

.skills h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.skills ul {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    list-style: none;
    gap: 1rem;
}

.skills li {
    background: var(--white);
    padding: 1rem;
    border-left: 4px solid var(--secondary-color);
    border-radius: 3px;
}

.contact-info {
    background: var(--white);
    padding: 1.5rem;
    border-left: 4px solid var(--secondary-color);
    border-radius: 3px;
    margin: 2rem 0;
}

.contact-info p {
    margin: 0.5rem 0;
}

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

.contact-info a:hover {
    color: var(--accent-color);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 1rem;
}

.skill-category h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.skill-category ul {
    list-style: disc;
    padding-left: 1.5rem;
}

.skill-category li {
    margin-bottom: 0.5rem;
}

/* Education Section */
.education {
    padding: 80px 20px;
    background: var(--white);
}

.education h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--primary-color);
}

.education-item {
    background: var(--light-bg);
    padding: 2rem;
    margin-bottom: 2rem;
    border-left: 4px solid var(--secondary-color);
    border-radius: 3px;
}

.education-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.education-item .institution {
    font-weight: bold;
    color: var(--secondary-color);
    margin-bottom: 0.3rem;
}

.education-item .details {
    color: #666;
    font-style: italic;
    margin-bottom: 1rem;
}

.coursework {
    list-style: disc;
    padding-left: 1.5rem;
    margin-top: 1rem;
}

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

/* Publications Section */
.publications {
    padding: 80px 20px;
    background: var(--light-bg);
}

.publications h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--primary-color);
}

.publication-item {
    background: var(--white);
    padding: 2rem;
    margin-bottom: 2rem;
    border-left: 4px solid var(--accent-color);
    border-radius: 3px;
}

.publication-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.publication-item p {
    margin-bottom: 0.5rem;
}

.publication-item .venue {
    font-style: italic;
    color: #666;
}

.publication-item a {
    display: inline-block;
    margin-top: 1rem;
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
}

.publication-item a:hover {
    color: var(--accent-color);
}

/* Conferences Section */
.conferences {
    padding: 80px 20px;
    background: var(--white);
}

.conferences h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--primary-color);
}

.conference-list {
    display: grid;
    gap: 1.5rem;
}

.conference-item {
    background: var(--light-bg);
    padding: 1.5rem;
    border-left: 4px solid var(--secondary-color);
    border-radius: 3px;
}

.conference-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.conference-item p {
    color: #666;
}

/* Teaching Section */
.teaching {
    padding: 80px 20px;
    background: var(--light-bg);
}

.teaching h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--primary-color);
}

.teaching-item {
    background: var(--white);
    padding: 2rem;
    margin-bottom: 2rem;
    border-left: 4px solid var(--secondary-color);
    border-radius: 3px;
}

.teaching-item h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.teaching-item ul {
    list-style: none;
    padding: 0;
}

.teaching-item li {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid #ddd;
}

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

.teaching-item li strong {
    color: var(--secondary-color);
}

.teaching-item li p {
    color: #666;
    margin-top: 0.5rem;
}

/* Projects Section */
.projects {
    padding: 80px 20px;
}

.projects h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
    color: var(--primary-color);
}

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

.project-card {
    background: var(--white);
    border: 1px solid #ddd;
    border-radius: 5px;
    padding: 2rem;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

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

.project-card p {
    color: #666;
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.project-card a {
    display: inline-block;
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
}

.project-card a:hover {
    color: var(--accent-color);
}

/* Contact Section */
.contact {
    background: var(--light-bg);
    padding: 80px 20px;
    text-align: center;
}

.contact h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.contact p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.contact-links a {
    padding: 12px 25px;
    background: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 5px;
    transition: background 0.3s ease;
}

.contact-links a:hover {
    background: var(--accent-color);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .about-content {
        grid-template-columns: 1fr;
    }

    .profile-picture img {
        max-width: 250px;
    }

    .nav-links {
        gap: 1rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .about h2,
    .projects h2,
    .contact h2 {
        font-size: 2rem;
    }

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

    .contact-links {
        flex-direction: column;
    }

    .contact-links a {
        width: 100%;
    }
}