* { box-sizing: border-box; }
body {
  margin: 0 auto; max-width: 860px; padding: 20px 16px 40px;
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #222; background: #f7f7f5; line-height: 1.6;
}
header h1 { font-size: 24px; margin: 8px 0 4px; }
header p { color: #666; margin: 0 0 16px; }
.panel {
  background: #fff; border: 1px solid #e3e3de; border-radius: 10px;
  padding: 16px; margin-bottom: 16px;
}
.panel > label, .opt-title { display: block; font-weight: 600; margin-bottom: 8px; }
textarea {
  width: 100%; padding: 10px; border: 1px solid #ccc; border-radius: 8px;
  font: inherit; resize: vertical; background: #fff;
}
textarea[readonly] { background: #fafaf7; }
.row { display: flex; align-items: center; gap: 10px; margin-top: 10px; flex-wrap: wrap; }
button {
  padding: 8px 16px; border: 1px solid #ccc; border-radius: 8px;
  background: #fff; font: inherit; cursor: pointer;
}
button:hover { background: #f0f0ea; }
button.primary { background: #2563eb; border-color: #2563eb; color: #fff; }
button.primary:hover { background: #1d4ed8; }
.options { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 16px; }
@media (max-width: 700px) { .options { grid-template-columns: 1fr; } }
.opt label { display: block; font-weight: 400; margin: 4px 0; }
.opt select { width: 100%; padding: 8px; border: 1px solid #ccc; border-radius: 8px; font: inherit; }
.hint { color: #888; font-size: 13px; margin: 6px 0 0; }
.stats { color: #555; font-size: 14px; }
summary { font-weight: 600; cursor: pointer; }
details textarea { margin-top: 10px; font-family: ui-monospace, Menlo, monospace; font-size: 14px; }
footer { color: #999; font-size: 13px; text-align: center; }