:root {
  --bg: #f4f5f7;
  --panel: #ffffff;
  --border: #e2e4e9;
  --text: #1f2329;
  --muted: #7a8190;
  --accent: #2f80ed;
  --danger: #ff6b35;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
}

.app { max-width: 1280px; margin: 0 auto; padding: 16px; }

.topbar {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 8px 4px 16px;
}
.topbar h1 { margin: 0; font-size: 22px; }
.topbar .sub { color: var(--muted); font-size: 13px; }
.topbar .github {
  margin-left: auto;
  align-self: center;
  color: var(--muted);
  line-height: 0;
}
.topbar .github:hover { color: var(--text); }

.layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 16px;
  align-items: start;
}

/* ---------- 预览区 ---------- */
.preview-col { min-width: 0; }

.dropzone {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 320px;
  border: 2px dashed var(--border);
  border-radius: 12px;
  background: var(--panel);
  cursor: pointer;
  text-align: center;
  transition: border-color .15s, background .15s;
  outline: none;
}
.dropzone:hover, .dropzone:focus, .dropzone.drag {
  border-color: var(--accent);
  background: #f0f6ff;
}
.dz-icon {
  font-size: 40px;
  color: var(--accent);
  line-height: 1;
}
.dz-title { margin: 12px 0 4px; font-size: 15px; }
.dz-hint { margin: 0; color: var(--muted); font-size: 13px; }

.stage {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  max-height: 72vh;
  overflow: auto;
}
#canvas {
  display: block;
  max-width: 100%;
  height: auto;
  background: #fff;
}

.status {
  padding: 8px 4px 0;
  color: var(--muted);
  font-size: 13px;
  min-height: 20px;
}

/* ---------- 侧栏 ---------- */
.side-col { display: flex; flex-direction: column; gap: 12px; }

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
}
.card h2 {
  margin: 0 0 12px;
  font-size: 14px;
  color: var(--muted);
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.count {
  font-size: 12px;
  color: var(--accent);
  background: #eaf2fe;
  border-radius: 999px;
  padding: 1px 8px;
}

.field { margin-bottom: 12px; }
.field label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  margin-bottom: 6px;
  color: var(--text);
}
.field label span { color: var(--muted); }
.field input[type="color"] {
  width: 100%;
  height: 34px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2px;
  background: #fff;
  cursor: pointer;
}
.field input[type="range"] { width: 100%; }
.field select {
  width: 100%;
  height: 34px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  padding: 0 8px;
}
.field.checkbox label { justify-content: flex-start; gap: 8px; margin: 0; cursor: pointer; }

.btnrow { display: flex; gap: 8px; margin-bottom: 8px; }
.btn {
  flex: 1;
  height: 34px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
  font-size: 13px;
  cursor: pointer;
}
.btn:hover:not(:disabled) { border-color: var(--accent); color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover:not(:disabled) { background: #2769c9; color: #fff; }
.btn:disabled { opacity: .45; cursor: not-allowed; }

.hint { margin: 6px 0 0; font-size: 12px; color: var(--muted); line-height: 1.6; }

.list { list-style: none; margin: 0; padding: 0; max-height: 300px; overflow: auto; }
.list .item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border-radius: 8px;
  font-size: 12px;
  cursor: pointer;
  color: var(--muted);
}
.list .item:hover { background: #f2f4f7; }
.list .item.selected { background: #eaf2fe; color: var(--accent); }
.list .item.excluded { text-decoration: line-through; opacity: .5; }
.list .idx {
  min-width: 22px;
  height: 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  color: #fff;
  border-radius: 6px;
  font-weight: 600;
}
.list .info { flex: 1; }
.list .pos { font-variant-numeric: tabular-nums; }