/* CSS Variables */
:root {
    --color-bg: #ffffff;
    --color-bg-alt: #fafafa;
    --color-text: #1a1a1a;
    --color-text-muted: #666666;
    --color-accent: #2563eb;
    --color-accent-hover: #1d4ed8;
    --color-border: #e5e5e5;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --max-width: 1100px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 5rem;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
}

/* Typography */
h1, h2, h3 {
    line-height: 1.3;
    font-weight: 600;
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
}

h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

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

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

/* Layout */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-2xl) 0;
}

.section-alt {
    background-color: var(--color-bg-alt);
}

/* Hero Section */
.hero {
    padding: var(--spacing-2xl) 0;
    border-bottom: 1px solid var(--color-border);
}

.hero-content {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.hero-photo {
    flex-shrink: 0;
}

.photo-placeholder {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background-color: var(--color-bg-alt);
    border: 2px dashed var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.hero-photo img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
}

.hero-text h1 {
    margin-bottom: var(--spacing-xs);
}

.tagline {
    color: var(--color-text-muted);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.affiliation {
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
}

.affiliation a {
    color: var(--color-text);
    font-weight: 500;
}

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

.intro {
    max-width: 540px;
    margin-bottom: var(--spacing-md);
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius);
    color: var(--color-text-muted);
    transition: all 0.2s ease;
}

.social-links a:hover {
    background-color: var(--color-bg-alt);
    color: var(--color-accent);
}

/* Publication Section */
.publication-card {
    background-color: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--spacing-lg);
}

.publication-content h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.authors {
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xs);
}

.venue {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-sm);
}

.abstract {
    display: none;
    margin: var(--spacing-md) 0;
    padding: var(--spacing-md);
    background-color: var(--color-bg);
    border-radius: var(--radius);
    font-size: 0.9375rem;
    color: var(--color-text-muted);
}

.abstract.show {
    display: block;
}

.abstract-toggle {
    background: none;
    border: none;
    color: var(--color-accent);
    cursor: pointer;
    font-size: 0.875rem;
    padding: 0;
    margin-bottom: var(--spacing-md);
}

.abstract-toggle:hover {
    text-decoration: underline;
}

.publication-links {
    display: flex;
    gap: var(--spacing-sm);
}

.btn {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background-color: var(--color-accent);
    color: white;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    transition: background-color 0.2s ease;
}

.btn:hover {
    background-color: var(--color-accent-hover);
    color: white;
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-accent);
    border: 1px solid var(--color-accent);
}

.btn-secondary:hover {
    background-color: var(--color-accent);
    color: white;
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.project-card {
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.section-alt .project-card {
    background-color: var(--color-bg);
}

.project-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.project-card.featured {
    border: 2px solid var(--color-accent);
    position: relative;
}

.project-card.featured::before {
    content: 'Coming Soon';
    position: absolute;
    top: 12px;
    right: 12px;
    background: var(--color-accent);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    z-index: 1;
}

.coming-soon-text {
    color: var(--color-accent);
    font-size: 0.875rem;
    font-weight: 500;
    font-style: italic;
}

.project-image {
    aspect-ratio: 16 / 9;
    overflow: hidden;
    background-color: var(--color-bg-alt);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
    color: var(--color-text-muted);
    font-size: 0.8125rem;
    text-align: center;
    padding: var(--spacing-sm);
}

.project-content {
    padding: var(--spacing-md);
}

.project-content p {
    color: var(--color-text-muted);
    font-size: 0.9375rem;
    margin-bottom: var(--spacing-sm);
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.tag {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    background-color: var(--color-bg-alt);
    border-radius: 4px;
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.project-links {
    display: flex;
    gap: var(--spacing-sm);
}

.project-links a {
    font-size: 0.875rem;
    font-weight: 500;
}

/* Footer */
.footer {
    padding: var(--spacing-xl) 0;
    border-top: 1px solid var(--color-border);
}

.footer-content {
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

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

.footer-note {
    color: var(--color-text-muted);
    font-size: 0.8125rem;
}

.footer-note a {
    color: var(--color-text-muted);
}

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

/* Responsive */
@media (max-width: 900px) {
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.25rem;
    }

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

    .intro {
        margin-left: auto;
        margin-right: auto;
    }

    .social-links {
        justify-content: center;
    }

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

    .section {
        padding: var(--spacing-xl) 0;
    }

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

    .btn {
        text-align: center;
    }
}