body{font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Helvetica Neue,Arial;margin:0;padding:0;background:#f5f7fa}.app header{background:#0f172a;color:#fff;padding:12px 16px}.app main{display:flex;gap:12px;padding:16px}.card{background:#fff;border-radius:8px;padding:12px;box-shadow:0 1px 2px #0000000d}.left,.right{width:280px}.center{flex:1}label{display:block;margin-top:8px;font-weight:600}input,textarea{width:100%;box-sizing:border-box;padding:8px;margin-top:4px}button{margin-top:8px;padding:8px 12px}.result{margin-top:10px;background:#f3f4f6;padding:8px}