:root {
    --bg: #0d1117;
    --text: #e6edf3;
    --text-muted: #8b949e;
    --link: #58a6ff;
    --border: #30363d;
    --card-bg: #161b22;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 20px;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

header {
    margin-bottom: 3rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 2rem;
}

header a {
    color: var(--text);
    text-decoration: underline;
}

header a:hover {
    color: var(--link);
}

h1 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.presentations {
    display: grid;
    gap: 1.5rem;
}

.presentation-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    transition: transform 0.2s, box-shadow 0.2s;
}

.presentation-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.presentation-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.presentation-title a {
    color: var(--text);
    text-decoration: none;
}

.presentation-title a:hover {
    color: var(--link);
}

.print-pdf-link {
    color: var(--link);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.print-pdf-link:hover {
    text-decoration: underline;
}

.presentation-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.presentation-description {
    color: var(--text);
}

.external-badge {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-style: italic;
}

footer {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

footer a {
    color: var(--text-muted);
    text-decoration: underline;
}

footer a:hover {
    color: var(--link);
}