* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans TC",
    "PingFang TC", "Microsoft JhengHei", sans-serif;
  background: #f6f8fa;
  color: #24292f;
}

.container {
  max-width: 980px;
  margin: 32px auto;
  padding: 0 16px 24px;
}

.hint {
  color: #57606a;
}

.panel {
  background: #fff;
  border: 1px solid #d0d7de;
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 16px;
}

label {
  display: block;
  margin-bottom: 12px;
  font-size: 14px;
}

input,
select,
button {
  margin-top: 6px;
  width: 100%;
  min-height: 36px;
  border: 1px solid #d0d7de;
  border-radius: 6px;
  padding: 8px 10px;
  font-size: 14px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 10px;
}

.actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

button {
  cursor: pointer;
  background: #0969da;
  color: #fff;
  border: 1px solid #0969da;
}

button:disabled {
  cursor: not-allowed;
  background: #8c959f;
  border-color: #8c959f;
}

#previewCanvas {
  width: 100%;
  height: auto;
  border: 1px dashed #d0d7de;
  display: block;
}