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

:root {
    --bg-color: #ffffff;
    --text-color: #000000;
    --link-color: #A8C8DC;
    --border-color: #000000;
}

body.dark-mode {
    --bg-color: #1a1a1a;
    --text-color: #e0e0e0;
    --link-color: #7BA3C4;
    --border-color: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--bg-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 12px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
    background: var(--link-color);
    border-radius: 6px;
    border: 2px solid var(--bg-color);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--link-color);
    opacity: 0.8;
}

/* Moon */
.moon {
    position: fixed;
    right: 30px;
    top: 100px;
    width: 40px;
    height: 40px;
    color: var(--link-color);
    z-index: 1000;
    transition: top 0.1s ease-out;
    pointer-events: none;
}

.moon svg {
    width: 100%;
    height: 100%;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}

/* Navigation */
.nav {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.3s ease;
}

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

.dark-mode-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    margin-left: auto;
    transition: color 0.3s ease;
}

.dark-mode-toggle:hover {
    color: var(--link-color);
}

.sun-icon {
    display: block;
}

.moon-icon {
    display: none;
}

body.dark-mode .sun-icon {
    display: none;
}

body.dark-mode .moon-icon {
    display: block;
}

/* Sections */
.section {
    margin-bottom: 4rem;
}

/* About Section */
.about-content {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 2rem;
    align-items: start;
}

.about-text {
    flex: 1;
}

.photo-placeholder {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: var(--bg-color);
    border: 2px solid var(--link-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.photo-placeholder svg {
    width: 80px;
    height: 80px;
}

.photo-placeholder p {
    font-size: 0.75rem;
    color: var(--text-color);
    margin-top: 0.5rem;
    text-align: center;
}

.name {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.title {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.bio {
    font-size: 1rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.links {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.link {
    color: var(--link-color);
    text-decoration: none;
}

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

.separator {
    color: var(--text-color);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-color);
    border-left: 4px solid var(--link-color);
    padding-left: 1rem;
}

.section-text {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-color);
}

/* Publications */
.publication {
    margin-bottom: 1.5rem;
    padding-left: 1rem;
    border-left: 2px solid var(--link-color);
}

.pub-title {
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-color);
}

.pub-authors {
    font-size: 0.95rem;
    margin-bottom: 0.25rem;
    color: var(--text-color);
}

.pub-venue {
    font-size: 0.9rem;
    font-style: italic;
    color: var(--text-color);
}

/* Teaching */
.course {
    margin-bottom: 1rem;
    padding-left: 1rem;
    border-left: 2px solid var(--link-color);
}

.course-title {
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-color);
}

.course-semester {
    font-size: 0.9rem;
    color: var(--text-color);
}

/* Contact */
.contact-text {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-color);
}

.contact-text strong {
    font-weight: 600;
}

/* Fun Section */
.fun-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.fun-item {
    padding: 1.5rem;
    border: 1px solid var(--link-color);
    border-radius: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.fun-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(168, 200, 220, 0.3);
    border-color: var(--text-color);
}

.fun-title {
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.fun-text {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-color);
}

/* Footer */
.footer {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--text-color);
}

.footer-text {
    font-size: 0.85rem;
    color: var(--text-color);
    opacity: 0.8;
    line-height: 1.6;
}

.footer-link {
    color: var(--link-color);
    text-decoration: none;
}

.footer-link:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 1.5rem;
    }
    
    .nav {
        gap: 1rem;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        justify-items: center;
    }
    
    .name {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.3rem;
    }
    
    .fun-content {
        grid-template-columns: 1fr;
    }
}