curl --request POST \
  --url https://api.iotools.cloud/v1/tool/css-custom-property-extractor \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "cssInput": ":root {\n  --primary-color: #464aff;\n  --spacing: 8px;\n}\n\n.btn {\n  color: var(--primary-color);\n  padding: var(--spacing);\n}\n\n.link {\n  color: var(--primary-color);\n}"
}
'

{
  "tool": "css-custom-property-extractor",
  "tool_version": "1.0.1",
  "outputs": {
    "summary": "Found 2 custom properties declared, referenced 3 times via var().",
    "propertiesTable": [
      {
        "property-name": "--primary-color",
        "declared-value": "#464aff",
        "usage-count": "2"
      },
      {
        "property-name": "--spacing",
        "declared-value": "8px",
        "usage-count": "1"
      }
    ]
  },
  "credits_used": 3,
  "credits_remaining": null
}