:root {
    --primary-color: #2c3e50;
    --secondary-color: #34495e;
    --accent-color: #e74c3c;
    --text-color: #333;
    --bg-color: #fdfdfd;
    --border-color: #eaeaea;
    --font-serif: 'Merriweather', 'Georgia', serif;
    --font-sans: 'Inter', 'Helvetica Neue', sans-serif;
    --max-width: 900px; /* Academic papers are often narrow column */
}

body {
    font-family: var(--font-serif);
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.8;
    margin: 0;
    padding: 0;
}

header {
    background-color: #fff;
    border-bottom: 1px solid var(--border-color);
    padding: 2rem 0;
    margin-bottom: 3rem;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    gap: 2rem;
    justify-content: center;
}

nav a {
    text-decoration: none;
    color: var(--secondary-color);
    font-family: var(--font-sans);
    font-weight: 500;
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    transition: color 0.2s;
}

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

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-sans);
    color: var(--primary-color);
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    line-height: 1.3;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-top: 0;
}

.subtitle {
    text-align: center;
    color: #7f8c8d;
    font-family: var(--font-sans);
    font-size: 1.1rem;
    margin-top: -0.5rem;
    margin-bottom: 2rem;
    font-weight: 300;
}

.abstract {
    background-color: #f8f9fa;
    border-left: 4px solid var(--accent-color);
    padding: 1.5rem;
    margin: 2rem 0;
    font-size: 0.95rem;
    color: #555;
    font-style: italic;
}

article {
    margin-bottom: 4rem;
}

.post-meta {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: #95a5a6;
    margin-bottom: 0.5rem;
    display: block;
}

a.read-more {
    display: inline-block;
    margin-top: 1rem;
    color: var(--accent-color);
    text-decoration: none;
    font-family: var(--font-sans);
    font-weight: 600;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s;
}

a.read-more:hover {
    border-bottom-color: var(--accent-color);
}

footer {
    border-top: 1px solid var(--border-color);
    padding: 3rem 0;
    margin-top: 4rem;
    text-align: center;
    font-family: var(--font-sans);
    color: #7f8c8d;
    font-size: 0.9rem;
}

/* Utilities */
.btn {
    display: inline-block;
    padding: 0.6rem 1.2rem;
    background-color: var(--primary-color);
    color: #fff;
    text-decoration: none;
    border-radius: 4px;
    font-family: var(--font-sans);
    transition: background-color 0.2s;
}

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

.tag {
    display: inline-block;
    padding: 0.2rem 0.5rem;
    background-color: #eee;
    color: #555;
    font-size: 0.75rem;
    border-radius: 3px;
    margin-right: 0.5rem;
    font-family: var(--font-sans);
}

@media (max-width: 600px) {
    h1 { font-size: 2rem; }
    nav ul { gap: 1rem; font-size: 0.85rem; }
}