/* CSS Variables for theming */
:root {
    --bg: #ffffff;
    --bg-secondary: #f8f9fa;
    --text: #333333;
    --text-secondary: #666666;
    --text-muted: #999999;
    --accent: #1a5f7a;
    --accent-hover: #134a5f;
    --border: #e5e5e5;
    --card-bg: #ffffff;
    --card-border: #e5e5e5;
    --tag-bg: #f0f4f5;
    --tag-text: #1a5f7a;
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #121212;
        --bg-secondary: #1e1e1e;
        --text: #e5e5e5;
        --text-secondary: #a0a0a0;
        --text-muted: #707070;
        --accent: #4db8d6;
        --accent-hover: #6dc8e2;
        --border: #2a2a2a;
        --card-bg: #1a1a1a;
        --card-border: #333333;
        --tag-bg: #1a2a2f;
        --tag-text: #4db8d6;
    }
}

/* Reset and base styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 17px;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    transition: background 0.3s, color 0.3s;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 80px 0 60px;
    border-bottom: 1px solid var(--border);
}

.profile-photo {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    margin-bottom: 24px;
    transition: transform 0.3s ease;
}

.profile-photo:hover {
    transform: scale(1.05);
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.tagline {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 24px;
}

.hero-links {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 10px 24px;
    background: var(--accent);
    color: #fff;
    text-decoration: none;
    border-radius: 6px;
    font-size: 0.95rem;
    transition: background 0.2s, transform 0.2s;
}

.btn:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
}

/* Sections */
section {
    padding: 60px 0;
    border-bottom: 1px solid var(--border);
}

section:last-of-type {
    border-bottom: none;
}

h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 24px;
    letter-spacing: -0.01em;
}

h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 4px;
}

p {
    margin-bottom: 16px;
}

p:last-child {
    margin-bottom: 0;
}

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

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

/* Expertise list */
.expertise-list {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 16px;
}

.expertise-list li {
    background: var(--tag-bg);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--tag-text);
    transition: transform 0.2s;
}

.expertise-list li:hover {
    transform: translateY(-2px);
}

/* Publications - Card style */
.publication {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 8px;
    padding: 20px 24px;
    margin-bottom: 16px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.publication:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

@media (prefers-color-scheme: dark) {
    .publication:hover {
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    }
}

.publication:last-child {
    margin-bottom: 0;
}

.publication h3 {
    margin-bottom: 8px;
}

.pub-meta {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 12px;
}

.pub-links {
    display: flex;
    gap: 16px;
    margin-bottom: 0;
}

.pub-links a {
    font-size: 0.9rem;
    font-weight: 500;
}

.pub-links a:hover {
    text-decoration: underline;
}

/* Project list - Monospace for package names */
.project-list {
    list-style: none;
    margin-top: 16px;
}

.project-list li {
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

.project-list li:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.project-list a {
    font-family: "SF Mono", "Fira Code", "Fira Mono", Menlo, Consolas, monospace;
    font-weight: 500;
    font-size: 1rem;
}

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

.project-desc {
    display: block;
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-top: 4px;
}

/* Teaching list */
.teaching-list {
    list-style: none;
}

.teaching-list li {
    margin-bottom: 12px;
    padding-left: 16px;
    border-left: 3px solid var(--accent);
}

.teaching-list li:last-child {
    margin-bottom: 0;
}

/* Footer */
footer {
    padding: 48px 0;
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

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

.copyright {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 600px) {
    .hero {
        padding: 60px 0 48px;
    }

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

    .profile-photo {
        width: 120px;
        height: 120px;
    }

    section {
        padding: 48px 0;
    }

    .expertise-list {
        gap: 6px;
    }

    .expertise-list li {
        font-size: 0.85rem;
        padding: 5px 12px;
    }

    .publication {
        padding: 16px 20px;
    }

    .footer-links {
        gap: 16px;
    }
}