body{margin:1rem}div{margin:1rem auto}table{border-collapse:collapse}th,td{padding:5px;border:1px solid black}.controls{margin:1rem 0}.book-table{width:100%;max-width:900px;border-collapse:collapse;border:1px solid #ddd}.book-table th,.book-table td{padding:10px 12px;border:1px solid #ddd;text-align:left}.error{margin:.5rem 0 1rem;padding:.75rem;background:red;border-radius:8px}.empty{text-align:center;padding:14px;color:#555}nav a{display:block}nav{display:flex;justify-content:space-around}#book-form .error-message{color:red;margin:1rem 0;font-family:Courier New,Courier,monospace}#book-form .form-row{display:flex;align-items:center;gap:1rem;margin:.25rem 0}