* { box-sizing: border-box; font-family: system-ui,Segoe UI,Roboto,Arial,sans-serif; }
body { background:#f6f8fa; color:#111; margin:0; padding:20px; }
main { max-width:900px; margin:0 auto; background:#fff; padding:24px; border-radius:8px; box-shadow:0 6px 24px rgba(15,23,42,0.08); }
h1 { margin:0 0 12px 0; }
.controls { display:grid; grid-template-columns:1fr 1fr; gap:12px; margin-bottom:16px; }
label { display:block; font-size:14px; }
label.full { grid-column: 1 / -1; }
input[type="text"], input[type="number"] { width:100%; padding:8px 10px; border:1px solid #d1d5db; border-radius:6px; }
.buttons { grid-column:1 / -1; display:flex; gap:8px; }
button { padding:8px 12px; border:0; border-radius:6px; background:#0366d6; color:#fff; cursor:pointer; }
button#clearBtn { background:#e5e7eb; color:#111; }
.result { background:#f3f4f6; padding:12px; border-radius:6px; white-space:pre-wrap; font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, monospace; }
.success { border-left:4px solid #16a34a; padding-left:8px; }
.failure { border-left:4px solid #dc2626; padding-left:8px; }
.mapping { margin-top:8px; }
.char-cell { display:inline-block; min-width:20px; padding:4px 6px; margin:2px; border-radius:4px; background:#fff; border:1px solid #d1d5db; }
.row { margin:6px 0; }
.notes { margin-top:12px; font-size:13px; color:#374151; }