:root {
    --primary-text: #2c3e50;
    --secondary-text: #546e7a;
    --link-color: #1976d2;
    --link-hover: #0d47a1;
    --border-color: #e0e0e0;
}

body {
    font-family: 'Work Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--primary-text);
    line-height: 1.7;
    font-size: 16px;
    background-color: #ffffff;
}

a {
    color: var(--link-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--link-hover);
}

h1, h2, h3 {
    font-family: 'Crimson Pro', Georgia, serif;
    font-weight: 600;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

h2 {
    font-size: 1.8rem;
    margin-top: 3rem;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
}

.header-section {
    padding: 4rem 0 2rem;
}

.profile-photo {
    width: 200px;
    height: 200px;
    object-fit: cover;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.social-links {
    margin: 1rem 0;
}

.social-links a {
    margin-right: 1.5rem;
    font-weight: 500;
}

.position-info {
    color: var(--secondary-text);
    font-size: 1.1rem;
    margin: 1rem 0;
}

.bio-text {
    font-size: 1.05rem;
    line-height: 1.8;
    margin: 2rem 0;
    padding: 2rem;
    background-color: #f8f9fa;
    border-left: 4px solid var(--link-color);
    border-radius: 4px;
    text-align: justify;
}

.contact-info {
    margin: 1.5rem 0;
    color: var(--secondary-text);
}

.publication-item {
    margin-bottom: 2.5rem;
}

.pub-image {
    width: 100%;
    max-width: 300px;
    height: auto;
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.pub-title {
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--primary-text);
}

.pub-authors {
    color: var(--secondary-text);
    font-size: 0.95rem;
    margin-bottom: 0.3rem;
}

.pub-venue {
    font-style: italic;
    color: var(--secondary-text);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.pub-award {
    color: #c62828;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.3rem;
}

.pub-links a {
    margin-right: 1rem;
    font-size: 0.9rem;
}

.teaching-item {
    margin-bottom: 1.5rem;
}

.teaching-item strong {
    color: var(--primary-text);
}

.news-item {
    margin-bottom: 1rem;
    padding-left: 1rem;
    border-left: 3px solid var(--link-color);
}

.news-date {
    color: var(--secondary-text);
    font-size: 0.9rem;
    font-weight: 600;
}

footer {
    margin-top: 5rem;
    padding: 2.5rem 0 1rem;
    text-align: center;
    color: var(--secondary-text);
    font-size: 0.9rem;
    border-top: 2px solid var(--border-color);
    background-color: #f8f9fa;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 1.5rem;
    text-align: left;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.footer-section {
    line-height: 1.8;
}

.footer-section strong {
    font-size: 1.1rem;
    color: var(--primary-text);
    margin-bottom: 0.75rem;
    display: block;
    font-weight: 600;
}

.footer-section a {
    color: var(--link-color);
    text-decoration: none;
    display: block;
    margin-bottom: 0.3rem;
    transition: color 0.2s ease;
}

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

.footer-update {
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.85rem;
    text-align: center;
}

@media (max-width: 768px) {
    footer {
        padding: 2rem 1rem 1rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .footer-section {
        text-align: center;
    }
    
    .footer-section a {
        display: inline-block;
        margin: 0.2rem 0;
    }
}

/* Course pages styles */
.course-list {
    margin: 2rem 0;
}

.course-section {
    margin: 3rem 0;
    padding: 2rem;
    background-color: #f8f9fa;
    border-radius: 8px;
    border-left: 4px solid var(--link-color);
}

.course-title {
    color: var(--primary-text);
    margin-top: 0;
    margin-bottom: 1rem;
    font-size: 1.6rem;
}

.course-description {
    margin: 1rem 0 1.5rem 0;
    padding: 1rem;
    background-color: #ffffff;
    border-radius: 4px;
    line-height: 1.6;
}

.course-link-item {
    margin-bottom: 1rem;
    padding: 1rem;
    border-left: 3px solid var(--link-color);
    background-color: #f8f9fa;
    transition: background-color 0.2s ease;
}

.course-link-item:hover {
    background-color: #e9ecef;
}

.course-link {
    display: block;
    color: var(--primary-text);
    text-decoration: none;
}

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

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

.course-meta {
    color: var(--secondary-text);
    margin: 0.5rem 0;
    font-size: 0.95rem;
}

.resource-type-title {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    font-size: 1.1rem;
    color: var(--primary-text);
    font-family: 'Work Sans', sans-serif;
}

.resource-list {
    list-style: none;
    padding-left: 1.5rem;
    margin-bottom: 1rem;
}

.resource-list li {
    margin-bottom: 0.75rem;
    position: relative;
}

.resource-list li:before {
    content: "→";
    position: absolute;
    left: -1.5rem;
    color: var(--link-color);
    font-weight: bold;
}

.resource-list a {
    font-weight: 500;
    transition: color 0.2s ease;
}

.resource-list a:hover {
    text-decoration: underline;
}

/* Research Philosophy Page Styles */
.research-philosophy {
    margin: 3rem 0;
}

.research-philosophy h3 {
    color: var(--primary-text);
    font-size: 1.5rem;
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.research-philosophy p {
    text-align: justify;
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.highlight-box {
    background-color: #f8f9fa;
    padding: 2rem;
    border-left: 4px solid var(--link-color);
    border-radius: 4px;
    margin: 2rem 0;
}

.pillar-list, .method-list {
    list-style: none;
    padding-left: 0;
    margin: 1.5rem 0;
}

.pillar-list li, .method-list li {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
    position: relative;
    line-height: 1.7;
}

.pillar-list li:before {
    content: "▸";
    position: absolute;
    left: 0;
    color: var(--link-color);
    font-size: 1.5rem;
    font-weight: bold;
}

.method-list li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #28a745;
    font-size: 1.2rem;
    font-weight: bold;
}

.key-insight {
    background-color: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 1rem 1.5rem;
    margin: 1.5rem 0;
    font-style: italic;
    border-radius: 4px;
}

/* Language Switcher */
.language-switcher {
    text-align: center;
    margin: 2rem 0;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.language-switcher .btn {
    margin: 0 0.5rem;
}

/* Services Page Styles */
.service-category {
    margin: 3rem 0;
}

.service-category h3 {
    color: var(--primary-text);
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.service-item {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background-color: #f8f9fa;
    border-left: 4px solid var(--link-color);
    border-radius: 4px;
    transition: box-shadow 0.3s ease;
}

.service-item:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.service-title {
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.service-title a {
    color: var(--primary-text);
    text-decoration: none;
}

.service-title a:hover {
    color: var(--link-hover);
}

.service-role {
    color: var(--link-color);
    font-weight: 500;
    margin-bottom: 0.3rem;
}

.service-year {
    color: var(--secondary-text);
    font-size: 0.9rem;
    font-style: italic;
    margin-bottom: 0.5rem;
}

.service-description {
    color: var(--secondary-text);
    line-height: 1.6;
    margin-top: 0.5rem;
}

@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }
    
    .header-section {
        padding: 2rem 0 1rem;
    }
    
    .profile-photo {
        width: 150px;
        height: 150px;
        margin-bottom: 1.5rem;
    }
    
    .research-philosophy p {
        text-align: left;
    }
}