src/language-css/loc.js/calculateLoc
function calculateLoc(node, text) {
  if (node.source) {
    node.source.startOffset = calculateLocStart(node, text);
    node.source.endOffset = calculateLocEnd(node, text);
  }

  for (const key in node) {
    const child = node[key];

    if (key === "source" || !child || typeof child !== "object") {
      continue;
    }

    if (child.type === "value-root" || child.type === "value-unknown") {
      calculateValueNodeLoc(
        child,
        getValueRootOffset(node),
        child.text || child.value
      );
    } else {
      calculateLoc(child, text);
    }
  }
}