body{font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;margin:0;background:#f5f7fa;color:#333}header,main,footer{max-width:760px;margin:auto;padding:1.5rem}.card{background:#fff;border-radius:8px;box-shadow:0 1px 4px #00000014;padding:1.5rem;margin:1rem 0}.btn{display:inline-block;background:#007aff;color:#fff;border:none;border-radius:4px;padding:.5rem 1rem;cursor:pointer}.btn:disabled{background:#9cb4d8;cursor:default}.scale>label{display:block;margin:.3rem 0}progress{width:100%;height:8px}