:root{--border:#d1d5db;--muted:#6b7280;--danger:#b91c1c}*{box-sizing:border-box}body{color:#111827;background:#f9fafb;margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif}main{max-width:640px;margin:0 auto;padding:2rem 1rem}h1{font-size:1.25rem}button,input{font:inherit}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.6}table{border-collapse:collapse;width:100%}th,td{text-align:left;border-bottom:1px solid var(--border);padding:.5rem;font-size:.9rem}.error{color:var(--danger)}.muted{color:var(--muted);font-size:.9rem}