@media (min-width: 576px) {
    .action-buttons { flex-direction: row; }
    .action-buttons .btn { flex: 1; }
}

@media (min-width: 768px) {
    .app-main { padding: 2.5rem 1rem; }
    .hero-title { font-size: 2.25rem; }
    .card { padding: 2rem; }
}