body { background: #f6f7f9; }
.narrow { max-width: 520px; }
.card, .message { border-radius: .5rem; }
.message { background: #fff; border: 1px solid #dee2e6; border-left: .35rem solid #6c757d; padding: 1rem; }
.message-out { border-left-color: #0d6efd; }
.message-in { border-left-color: #198754; }
pre { margin: 0; white-space: pre-wrap; overflow-wrap: anywhere; font: inherit; }
.preview { background: #f8f9fa; border: 1px solid #dee2e6; padding: 1rem; }