:root{--bg:#fafaf7;--ink:#1a1a1a;--muted:#6b6b6b;--line:#d9d9d2;--accent:#0f7b5f;--error:#b42318}*{box-sizing:border-box}body{background:var(--bg);color:var(--ink);margin:0;font:20px/1.5 system-ui,-apple-system,Segoe UI,sans-serif}main{max-width:480px;margin:0 auto;padding:48px 16px}h1{margin:0 0 32px;font-size:36px;line-height:1.2}label{margin-bottom:8px;font-weight:600;display:block}.field{margin-bottom:24px}input{width:100%;font:inherit;border:2px solid var(--line);color:var(--ink);background:#fff;border-radius:8px;padding:12px 16px;font-size:28px}input:focus{border-color:var(--accent);outline:none}.tips{border:0;gap:12px;margin:0 0 32px;padding:0;display:flex}.tips legend{margin-bottom:8px;padding:0;font-weight:600}.tips button{font:inherit;border:2px solid var(--line);color:var(--ink);cursor:pointer;background:#fff;border-radius:8px;flex:1;padding:14px 0;font-size:24px;font-weight:600}.tips button[aria-pressed=true]{background:var(--accent);border-color:var(--accent);color:#fff}.result{border-top:2px solid var(--line);padding-top:24px}.row{color:var(--muted);justify-content:space-between;margin-bottom:8px;display:flex}.row output{color:var(--ink);font-variant-numeric:tabular-nums}.row.main{color:var(--ink);margin-top:16px;font-size:32px;font-weight:700}.row.main output{color:var(--accent)}.message{color:var(--error);margin:0;font-weight:600}