:root {
    --bg: #ffffff;
    --text: #1a1a1a;
    --accent: #ff6b00; /* Substack Orange */
    --muted: #666;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Georgia, serif;
    line-height: 1.6;
    margin: 0;
    color: var(--text);
    background: var(--bg);
}

.container {
    max-width: 680px;
    margin: 0 auto;
    padding: 0 20px;
}

nav {
    padding: 20px 0;
    border-bottom: 1px solid #eee;
    margin-bottom: 40px;
}

nav a { text-decoration: none; color: var(--text); font-size: 1.2rem; }

h1 { font-size: 2.5rem; line-height: 1.2; margin-bottom: 10px; }

.meta { color: var(--muted); font-size: 0.9rem; margin-bottom: 30px; }

/* Post List Styling */
.post-list { list-style: none; padding: 0; }
.post-list li { 
    padding: 20px 0; 
    border-bottom: 1px solid #f0f0f0; 
    display: flex; 
    flex-direction: column;
}
.post-list .date { font-size: 0.8rem; color: var(--muted); text-transform: uppercase; }
.post-list a { 
    font-size: 1.3rem; 
    font-weight: bold; 
    text-decoration: none; 
    color: var(--text); 
}
.post-list a:hover { color: var(--accent); }

/* Code and Math spacing */
pre { margin: 25px 0; border-radius: 8px; }
.post-body { font-size: 1.1rem; }

.back-link { display: inline-block; margin-top: 40px; color: var(--accent); text-decoration: none; font-weight: bold; }

@media (max-width: 600px) {
    h1 { font-size: 1.8rem; }
}