@import url(foo.css);
@media print {}
@media (min-width: 640px) and (min-height: 1000px) {}
@supports (top: 50vmax)
	or (top: 50vw) {}
@main-color: red;

----------------------------------------------------

[
	["atrule", [
		["rule", "@import"],
		["url", [
			["function", "url"],
			["punctuation", "("],
			"foo.css",
			["punctuation", ")"]
		]],
		["punctuation", ";"]
	]],
	["atrule", [
		["rule", "@media"],
		" print"
	]],
	["punctuation", "{"],
	["punctuation", "}"],
	["atrule", [
		["rule", "@media"],
		["punctuation", "("],
		["property", "min-width"],
		["punctuation", ":"],
		" 640px",
		["punctuation", ")"],
		["keyword", "and"],
		["punctuation", "("],
		["property", "min-height"],
		["punctuation", ":"],
		" 1000px",
		["punctuation", ")"]
	]],
	["punctuation", "{"],
	["punctuation", "}"],
	["atrule", [
		["rule", "@supports"],
		["punctuation", "("],
		["property", "top"],
		["punctuation", ":"],
		" 50vmax",
		["punctuation", ")"],
		["keyword", "or"],
		["punctuation", "("],
		["property", "top"],
		["punctuation", ":"],
		" 50vw",
		["punctuation", ")"]
	]],
	["punctuation", "{"],
	["punctuation", "}"],
	["atrule", [
		["rule", "@main-color"],
		["punctuation", ":"],
		" red",
		["punctuation", ";"]
	]]
]

----------------------------------------------------

Checks for at-rules.
Also checks for LESS variables.
