:root {
  --bg: #f7f8fa;
  --card-bg: #ffffff;
  --text: #1f2328;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #2563eb;
  --primary-foreground: #ffffff;
  --secondary: #e5e7eb;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", Arial, system-ui;
  color: var(--text);
  background: var(--bg);
}
.header {
  padding: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.header h1 { margin: 0; font-size: 24px; }
.main {
  display: grid;
  grid-template-columns: 420px 1fr;
  gap: 16px;
  padding: 0 24px 24px;
  max-width: 1200px;
  margin: 0 auto;
  align-items: stretch;
}
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
}
.column-card {
  height: 100%;
  display: flex;
  flex-direction: column;
}
.group + .group { margin-top: 12px; }
.column-card .actions {
  margin-top: auto;
}
.card h2 {
  margin: 0 0 12px;
  font-size: 16px;
}
.upload input[type="file"] {
  width: 100%;
}
.hint {
  margin-top: 8px;
  font-size: 12px;
  color: var(--muted);
}
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 13px;
}
input[type="number"],
input[type="color"],
select,
textarea {
  width: 100%;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  background: #fff;
}
.input-with-suffix {
  display: flex;
  align-items: center;
  gap: 8px;
}
.actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 16px;
}
button {
  height: 40px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #fff;
  cursor: pointer;
  font-size: 14px;
}
button.primary {
  background: var(--primary);
  color: var(--primary-foreground);
  border-color: var(--primary);
}
button.secondary {
  background: #fff;
}
.preview-card { height: 100%; }
.preview {
  width: 100%;
  border: 1px dashed var(--border);
  border-radius: 8px;
  display: block;
  padding: 12px;
  background: #fafafa;
}
.placeholder {
  color: var(--muted);
  font-size: 13px;
}
.preview canvas {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
}
.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  transform: translateX(-50%);
  background: #1f2937;
  color: #fff;
  padding: 10px 14px;
  border-radius: 10px;
  font-size: 13px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s ease;
}
.toast.show { opacity: 1; }
@media (max-width: 980px) {
  .main { grid-template-columns: 1fr; }
}