:root{--bg:#f7f7fb;--card:#fff;--text:#1f2937;--muted:#6b7280;--accent:#2563eb;--warn:#b91c1c}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif}
.wrap{max-width:960px;margin:24px auto;padding:0 16px}
h1{font-size:clamp(20px,2.6vw,28px);margin:0 0 8px}
.lead{color:var(--muted);margin-top:0}
.grid{display:grid;gap:16px}
.grid.two{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.card{background:var(--card);border-radius:12px;box-shadow:0 1px 2px rgba(0,0,0,.05),0 8px 24px rgba(0,0,0,.06);padding:16px}
label{display:block;font-weight:600;margin-bottom:6px}
input[type=number]{width:100%;padding:10px 12px;font-size:16px;border-radius:10px;border:1px solid #e5e7eb}
input[type=number]:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(37,99,235,.15)}
.hint{font-size:12px;color:var(--muted);margin-top:4px}
.row{display:flex;gap:8px;align-items:center}
.row>*:last-child{flex:0 0 auto}
.result{font-size:18px;font-weight:700;margin-left:auto}
.warn{color:var(--warn);font-weight:700}
.muted{color:var(--muted)}
.small{font-size:12px}
.footer{margin-top:16px}
.badge{display:inline-block;padding:4px 8px;border-radius:999px;background:#eef2ff;color:#1e40af;font-weight:600;font-size:12px;margin-left:8px}
.tight{margin:0 0 8px 18px}
hr{border:none;border-top:1px solid #eee;margin:8px 0}