body { font-family: system-ui; background:#f6f7f9; margin:0; padding:24px; }
.card { max-width:720px; margin:0 auto; background:#fff; border-radius:12px; padding:20px; box-shadow:0 2px 10px rgba(0,0,0,.08); }
.btn { padding:10px 14px; border:0; border-radius:10px; background:#111; color:#fff; cursor:pointer; }
.input { width:100%; padding:10px 12px; border-radius:10px; border:1px solid #ddd; margin:8px 0 12px; }
.label { display:block; font-size:12px; color:#555; }
.hint { color:#777; font-size:12px; }
.pre { background:#111; color:#0f0; padding:12px; border-radius:10px; overflow:auto; }
code { background:#f0f0f0; padding:2px 6px; border-radius:6px; }