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

:root {
    --color-text: #2c2c2c;
    --color-text-light: #555;
    --color-text-muted: #777;
    --color-link: #1a5276;
    --color-link-hover: #0e3a5c;
    --color-background: #fafafa;
    --color-white: #ffffff;
    --color-border: #e0e0e0;
    --color-accent: #1a5276;
    
    --font-serif: 'Source Serif 4', Georgia, serif;
    --font-sans: 'Source Sans 3', -apple-system, BlinkMacSystemFont, sans-serif;
    
    --max-width: 1100px;
    --spacing-unit: 1rem;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 calc(var(--spacing-unit) * 2);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header & Navigation */
header {
    padding: calc(var(--spacing-unit) * 2) 0;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: calc(var(--spacing-unit) * 3);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-unit);
}

.nav-name {
    font-family: var(--font-serif);
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: -0.02em;
}

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

.nav-links {
    list-style: none;
    display: flex;
    gap: calc(var(--spacing-unit) * 2);
}

.nav-links a {
    font-size: 0.95rem;
    color: var(--color-text-light);
    text-decoration: none;
    padding-bottom: 2px;
    border-bottom: 2px solid transparent;
    transition: color 0.2s ease, border-color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-text);
    border-bottom-color: var(--color-accent);
}

/* Main Content */
main {
    flex: 1;
}

/* Home Page - Profile Section (Option C: 50/50 split) */
.profile-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: calc(var(--spacing-unit) * 4);
    margin-bottom: calc(var(--spacing-unit) * 4);
    align-items: center;
    min-height: 480px;
}

.profile-photo {
    height: 480px;
    overflow: hidden;
    border-radius: 8px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

.profile-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top;
}

.profile-text h1 {
    font-family: var(--font-serif);
    font-size: 2.4rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 1.5);
    color: var(--color-text);
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.profile-text p {
    margin-bottom: var(--spacing-unit);
    font-size: 1.1rem;
    color: var(--color-text);
}

.profile-text a {
    color: var(--color-link);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s ease;
}

.profile-text a:hover {
    border-bottom-color: var(--color-link);
}

/* Contact Info */
.contact-info {
    margin-top: calc(var(--spacing-unit) * 2);
    padding-top: calc(var(--spacing-unit) * 1.5);
    border-top: 1px solid var(--color-border);
}

.contact-info h2 {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 0.5);
    color: var(--color-text);
}

.contact-info p {
    font-size: 0.95rem;
    margin-bottom: calc(var(--spacing-unit) * 0.5);
    color: var(--color-text-light);
}

.email {
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    font-size: 0.9rem !important;
}

/* Social Links */
.social-links {
    margin-top: calc(var(--spacing-unit) * 1.5);
    display: flex;
    gap: calc(var(--spacing-unit) * 0.75);
    flex-wrap: wrap;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    font-size: 1.2rem;
    color: var(--color-text-light);
    text-decoration: none;
    border: 1px solid var(--color-border);
    border-radius: 50%;
    transition: all 0.2s ease;
}

.social-links a:hover {
    background-color: var(--color-link);
    color: var(--color-white);
    border-color: var(--color-link);
}

/* News Section */
.news-section {
    padding-top: calc(var(--spacing-unit) * 2);
    border-top: 1px solid var(--color-border);
}

.news-section h2 {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 1.5);
    color: var(--color-text);
}

.news-list {
    list-style: none;
}

.news-list li {
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: var(--spacing-unit);
    padding: calc(var(--spacing-unit) * 0.75) 0;
    border-bottom: 1px solid var(--color-border);
}

.news-list li:last-child {
    border-bottom: none;
}

.news-date {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    font-weight: 500;
}

.news-item {
    font-size: 0.95rem;
    color: var(--color-text);
}

/* Research Page */
.page-title {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 2);
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.research-section {
    margin-bottom: calc(var(--spacing-unit) * 3);
}

.research-section h2 {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 1.5);
    color: var(--color-text);
    padding-bottom: calc(var(--spacing-unit) * 0.5);
    border-bottom: 2px solid var(--color-accent);
    display: inline-block;
}

.paper {
    margin-bottom: calc(var(--spacing-unit) * 2.5);
    padding-bottom: calc(var(--spacing-unit) * 2);
    border-bottom: 1px solid var(--color-border);
}

.paper:last-child {
    border-bottom: none;
}

.paper-title {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: calc(var(--spacing-unit) * 0.3);
}

.paper-authors {
    font-size: 0.95rem;
    color: var(--color-text-light);
    margin-bottom: calc(var(--spacing-unit) * 0.5);
    font-style: italic;
}

.paper-status {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: calc(var(--spacing-unit) * 0.75);
}

.paper-abstract {
    font-size: 0.95rem;
    color: var(--color-text);
    line-height: 1.75;
    text-align: justify;
}

.paper-abstract summary {
    cursor: pointer;
    color: var(--color-link);
    font-weight: 500;
    margin-bottom: calc(var(--spacing-unit) * 0.5);
}

.paper-abstract summary:hover {
    text-decoration: underline;
}

.paper-abstract p {
    margin-top: calc(var(--spacing-unit) * 0.75);
    padding-left: var(--spacing-unit);
    border-left: 3px solid var(--color-border);
}

/* CV Page */
.cv-section {
    text-align: center;
    padding: calc(var(--spacing-unit) * 4) 0;
}

.cv-section p {
    margin-bottom: calc(var(--spacing-unit) * 2);
    font-size: 1.05rem;
    color: var(--color-text-light);
}

.cv-download {
    display: inline-block;
    padding: 0.8rem 1.8rem;
    background-color: var(--color-accent);
    color: var(--color-white);
    text-decoration: none;
    border-radius: 4px;
    font-weight: 500;
    transition: background-color 0.2s ease;
}

.cv-download:hover {
    background-color: var(--color-link-hover);
}

.cv-embed {
    margin-top: calc(var(--spacing-unit) * 3);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    overflow: hidden;
}

.cv-embed iframe {
    width: 100%;
    height: 800px;
    border: none;
}

/* Footer */
footer {
    margin-top: auto;
    padding: calc(var(--spacing-unit) * 2) 0;
    border-top: 1px solid var(--color-border);
    text-align: center;
}

footer p {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

/* Responsive Design */
@media (max-width: 900px) {
    .profile-section {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .profile-photo {
        max-width: 400px;
        height: 450px;
        margin: 0 auto;
    }
    
    .contact-info {
        text-align: center;
    }
    
    .social-links {
        justify-content: center;
    }
}

@media (max-width: 600px) {
    .profile-photo {
        max-width: 100%;
        height: 400px;
    }
    
    .profile-text h1 {
        font-size: 1.8rem;
    }
    
    .news-list li {
        grid-template-columns: 1fr;
        gap: calc(var(--spacing-unit) * 0.25);
    }
    
    .news-date {
        font-size: 0.85rem;
    }
    
    nav {
        flex-direction: column;
        text-align: center;
    }
    
    .nav-links {
        gap: var(--spacing-unit);
    }
}

@media (max-width: 500px) {
    :root {
        --spacing-unit: 0.875rem;
    }
    
    html {
        font-size: 15px;
    }
    
    .container {
        padding: 0 var(--spacing-unit);
    }
}