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

:root {
    --primary-color: #1f2937;
    --secondary-color: #6b7280;
    --text-color: #374151;
    --bg-color: #ffffff;
    --light-bg: #f9fafb;
    --border-color: #e5e7eb;
    --hover-color: #374151;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 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;
}

/* Navigation */
.navbar {
    background-color: var(--bg-color);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.nav-logo h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

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

.nav-link.active {
    color: var(--secondary-color);
    border-bottom: 2px solid var(--secondary-color);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--primary-color);
    transition: all 0.3s ease;
}

/* Hero Section */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, #374151 0%, #1f2937 100%);
    color: white;
}

.hero-content {
    display: flex;
    align-items: center;
    gap: 3rem;
    max-width: 1200px;
    margin: 0 auto;
}

.hero-image {
    flex: 0 0 200px;
    position: relative;
}

.hero-image img {
    width: 200px;
    height: 200px;
    object-fit: cover;
    border-radius: 50%;
    border: 5px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.hero-placeholder {
    display: none;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    font-weight: 700;
    flex-shrink: 0;
    border: 5px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.hero-text {
    flex: 1;
    text-align: left;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.hero-subtitle {
    font-size: 2rem;
    font-weight: 400;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.hero-description {
    font-size: 1.1rem;
    line-height: 1.8;
    opacity: 0.9;
}

/* Skills Section */
.skills {
    padding: 80px 0;
    background-color: var(--light-bg);
}

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

.skill-card {
    background-color: var(--bg-color);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-align: center;
}

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

.skill-icon {
    width: 80px;
    height: 80px;
    object-fit: contain;
    margin-bottom: 1rem;
    border-radius: 8px;
}

.skill-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.skill-card p {
    color: #666;
    font-size: 1rem;
}

/* Section Titles */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    text-align: center;
    color: var(--primary-color);
}

/* Experience Section */
.experience {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.experience-item {
    margin-bottom: 3rem;
    padding: 2rem;
    background-color: var(--light-bg);
    border-radius: 8px;
    border-left: 4px solid var(--secondary-color);
}

.experience-header {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    margin-bottom: 1rem;
}

.company-logo {
    width: 80px;
    height: 80px;
    object-fit: contain;
    flex-shrink: 0;
    background-color: white;
    padding: 0.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.company-logo-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

.experience-title {
    flex: 1;
}

.experience-item h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.experience-item h4 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
    font-weight: 600;
}

.experience-item .date {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 1rem;
    font-style: italic;
}

.experience-item .description {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-color);
    margin-top: 1rem;
}

.experience-item .description ul {
    margin: 0;
    padding-left: 1.25rem;
    list-style-type: disc;
}

.experience-item .description li {
    margin-bottom: 0.5rem;
}

/* Education Section */
.education {
    padding: 80px 0;
    background-color: var(--light-bg);
}

.education-item {
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: 3rem;
    padding: 2rem;
    background-color: var(--bg-color);
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.education-item:last-child {
    margin-bottom: 0;
}

.education-header {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.university-logo {
    width: 100px;
    height: 100px;
    object-fit: contain;
    flex-shrink: 0;
    background-color: var(--light-bg);
    padding: 0.5rem;
    border-radius: 8px;
}

.education-item h3 {
    font-size: 1.8rem;
    margin-bottom: 0;
    color: var(--primary-color);
}

.education-item h4 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    margin-top: 1.5rem;
    color: var(--secondary-color);
    font-weight: 600;
}

.education-item .date {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 0.5rem;
}

.education-item .gpa {
    font-size: 1rem;
    color: var(--text-color);
    font-weight: 500;
}

/* Publications Section */
.publications {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.publication-item {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
    background-color: var(--light-bg);
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.publication-link {
    text-decoration: none;
    color: inherit;
    display: block;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

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

.publication-link:hover .publication-read {
    text-decoration: underline;
}

.publication-item h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.publication-venue {
    font-size: 1rem;
    color: var(--secondary-color);
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.publication-date {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 0.75rem;
}

.publication-read {
    font-size: 0.95rem;
    color: var(--primary-color);
    font-weight: 500;
}

/* Portfolio Section */
.portfolio {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.portfolio-subtitle {
    text-align: center;
    margin-bottom: 2rem;
    color: #666;
    font-style: italic;
}

.portfolio-tcr-link {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
}

.portfolio-tcr-link:hover {
    text-decoration: underline;
}

.portfolio-caption {
    font-size: 0.95rem;
    color: var(--primary-color);
    margin-top: 0.5rem;
}

.portfolio-item a {
    text-decoration: none;
    color: inherit;
}

.portfolio-item a:hover .portfolio-caption {
    text-decoration: underline;
}

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

.portfolio-item {
    text-align: center;
}

.portfolio-item h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.portfolio-image {
    width: 100%;
    height: 420px;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
    background-color: var(--light-bg);
}

.portfolio-image:hover {
    transform: scale(1.05);
}

.portfolio-link {
    display: block;
    width: 100%;
    height: 100%;
    text-decoration: none;
}

.portfolio-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #374151 0%, #1f2937 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
    font-weight: 600;
}

.portfolio-thumbnail {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* Tools Section */
.tools-section {
    padding: 80px 0;
    background-color: var(--light-bg);
}

/* Contact Section */
.contact {
    padding: 80px 0;
    background-color: var(--light-bg);
}

.contact-info {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.contact-item {
    text-align: center;
    flex: 0 0 auto;
    min-width: 200px;
}

.contact-link {
    text-decoration: none;
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 500;
    transition: color 0.3s ease;
    display: block;
    padding: 1rem 2rem;
    background-color: var(--bg-color);
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    min-width: 200px;
    width: 100%;
    box-sizing: border-box;
}

.contact-link:hover {
    color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

.contact-text {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    cursor: default;
}

.contact-text:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

.contact-label {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--primary-color);
}

.contact-value {
    font-size: 1rem;
    color: var(--text-color);
    font-weight: 400;
}

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

.cookie-notice {
    margin-top: 1rem;
    padding: 1rem;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

.cookie-notice p {
    margin-bottom: 0.5rem;
}

.cookie-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1rem;
}

.cookie-btn {
    padding: 0.5rem 1.5rem;
    border: 1px solid white;
    background-color: transparent;
    color: white;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.cookie-btn:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg-color);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
    }

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

    .hamburger {
        display: flex;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

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

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero-content {
        flex-direction: column;
        text-align: center;
    }

    .hero-image {
        flex: 0 0 150px;
    }

    .hero-image img {
        width: 150px;
        height: 150px;
    }

    .hero-placeholder {
        width: 150px;
        height: 150px;
        font-size: 3rem;
    }

    .hero-text {
        text-align: center;
    }

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

    .hero-subtitle {
        font-size: 1.5rem;
    }

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

    .company-logo,
    .company-logo-placeholder {
        width: 60px;
        height: 60px;
    }

    .education-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

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

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

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

    .contact-info {
        flex-direction: column;
        gap: 1.5rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .container {
        padding: 0 15px;
    }
}