body { font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial; background: #f6f8fb; color:#111; margin:0; }
.wrap { max-width:720px; margin:20px auto; padding:16px; }
header h1 { margin:0 0 12px 0; font-size:20px; }
.card { background:white; border-radius:8px; padding:12px; box-shadow:0 1px 4px rgba(0,0,0,0.06); margin-top:12px; }
.btn { display:inline-block; padding:10px 16px; border:none; border-radius:8px; background:#2b8cff; color:white; font-size:14px; cursor:pointer; }
pre { white-space:pre-wrap; word-break:break-word; }
footer { margin-top:20px; font-size:12px; color:#666; }