:root {
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #2d3436;
    --text-muted: #636e72;
    --accent-primary: #0984e3;
    --accent-secondary: #00cec9;
    --font-main: 'Inter', system-ui, -apple-system, sans-serif;
    --font-heading: 'Outfit', sans-serif;
    --shadow-soft: 0 2px 10px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 5px 15px rgba(0, 0, 0, 0.1);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    line-height: 1.5;
    overflow-x: hidden;
    font-size: 15px;
    /* Slightly smaller base font for density */
}

a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: all 0.2s ease;
    font-weight: 500;
}

a:hover {
    color: var(--accent-secondary);
    text-decoration: underline;
}

/* Header & Nav - Compact */
header {
    position: sticky;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    z-index: 1000;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    box-shadow: var(--shadow-soft);
    padding: 0.5rem 0;
}

nav {
    max-width: 1400px;
    /* Wider container */
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-color);
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    list-style: none;
    margin: 0;
}

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

.nav-links a:hover {
    color: var(--accent-primary);
    text-decoration: none;
}

/* Layout Utility */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
}

/* Hero - Compact */
.hero {
    text-align: center;
    padding: 3rem 1rem;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    margin-bottom: 2rem;
    border-radius: 0 0 20px 20px;
}

.hero h1 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.hero p {
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto 1.5rem;
    color: var(--text-muted);
}

.btn {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    background: var(--accent-primary);
    color: white;
    border-radius: 4px;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.btn:hover {
    background: var(--accent-secondary);
    color: white;
    text-decoration: none;
    transform: translateY(-1px);
}

/* Compact Grid Layout */
.main-grid {
    display: grid;
    grid-template-columns: 280px 1fr;
    /* Sidebar for people, Main for content */
    gap: 2rem;
    align-items: start;
}

/* Section Styling */
section {
    margin-bottom: 3rem;
}

.section-title {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    color: var(--text-color);
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--accent-secondary);
    display: inline-block;
}

/* People - Sidebar Style */
.people-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.person-card-compact {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--card-bg);
    padding: 0.75rem;
    border-radius: 8px;
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(0, 0, 0, 0.03);
}

.person-img-small {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    object-fit: cover;
}

.person-info h4 {
    font-size: 0.95rem;
    margin: 0;
    line-height: 1.2;
}

.person-info span {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Research Grid - Dense */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.research-card {
    background: var(--card-bg);
    padding: 1.25rem;
    border-radius: 8px;
    box-shadow: var(--shadow-soft);
    border-left: 4px solid var(--accent-primary);
}

.research-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--accent-primary);
}

.research-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin: 0;
}

/* Publications - Categorized & Dense */
.pub-category {
    margin-bottom: 2rem;
}

.pub-category h3 {
    font-size: 1.2rem;
    color: var(--text-color);
    margin-bottom: 1rem;
    background: #eef2f7;
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

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

.pub-item {
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    font-size: 0.9rem;
    display: flex;
    gap: 0.5rem;
    align-items: baseline;
}

.pub-item:last-child {
    border-bottom: none;
}

.pub-year {
    font-weight: 700;
    color: var(--accent-primary);
    min-width: 45px;
}

.pub-content {
    color: var(--text-color);
}

.pub-title-link {
    font-weight: 600;
    color: var(--text-color);
}

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

.pub-journal {
    font-style: italic;
    color: var(--accent-secondary);
}

/* Footer - Compact */
footer {
    background: var(--white);
    border-top: 1px solid #eee;
    padding: 2rem 0;
    margin-top: 3rem;
    font-size: 0.9rem;
    text-align: center;
    color: var(--text-muted);
}

@media (max-width: 900px) {
    .main-grid {
        grid-template-columns: 1fr;
    }

    .people-list {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}

/* Interactive Publications */
.pub-category h3 {
    cursor: pointer;
    position: relative;
    padding-left: 20px;
    transition: color 0.3s ease;
}

.pub-category h3::before {
    content: '▶';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    font-size: 0.8em;
    transition: transform 0.3s ease;
}

.pub-category h3.active::before {
    transform: translateY(-50%) rotate(90deg);
}

.pub-category h3:hover {
    color: var(--accent-primary);
}

.pub-list {
    display: none;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.pub-list.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}