diff --git a/js/21-transitions-animations.js b/js/21-transitions-animations.js
new file mode 100644
index 0000000..d18d6c3
--- /dev/null
+++ b/js/21-transitions-animations.js
@@ -0,0 +1,47 @@
+export default function compute() {
+
+let ret = {
+	properties: [],
+	timingFunctions: new Set(),
+	animationNames: new Set()
+};
+
+walkDeclarations(ast, ({property, value}) => {
+	if (["inherit", "initial", "unset", "revert"].includes(value)) {
+		return;
+	}
+	
+	if (property === "transition-property") {
+		ret.properties.add(value);
+	}
+	else if (property === "transition-timing-functon") {
+		let name = value.match(/^[a-z-]+)/)[0];
+		ret.timingFunctions
+	}
+	else if (property === "transition") {
+		// Extract property name and timing function
+		let keywords = (value.match(/(^|\s)(d|r|[cr]?x|[cr]?y|[a-z-]{3,})(?=\s|$)/) || []);
+		let properties = [], easings = [];
+
+		for (let keyword of keywords) {
+
+		}
+						// Drop timing functions and global values
+		                 .filter(p => !/^(?:ease(-in|-out)?|)$/.test(p));
+		ret.properties.push(...properties);
+	}
+}, {
+	properties: /^(transition|animation)(?=$|-)/g
+})
+
+// Animation names
+walkRules(ast, rule => {
+	ret.animationNames.add(rule.name);
+}, {type: "keyframes"});
+
+ret.properties = [...new Set(ret.properties)];
+ret.animationNames = [...ret.animationNames];
+
+return ret;
+
+}