body{background:#f4f6f8;font-family:Arial}.navbar{background:#0f172a;justify-content:center;gap:20px;padding:15px;display:flex}.navbar button{color:#fff;background:#4f46e5;border:none;border-radius:10px;padding:10px 20px}.container{padding:30px}.grid{justify-content:center;gap:20px;display:flex}.card{text-align:center;background:#fff;border-radius:15px;width:250px;padding:20px;box-shadow:0 4px 10px #0000001a}.stock{color:green;font-weight:700}.out{color:red;font-weight:700}button{color:#fff;background:#4f46e5;border:none;border-radius:8px;margin-top:10px;padding:10px}button:disabled{background:gray}.form{gap:10px;margin:20px 0;display:flex}.book{background:#fff;border-radius:10px;justify-content:space-between;margin:10px 0;padding:15px;display:flex}.remove{background:red}