Simple CSS optimizer in PHP.

test.php

<?php

/**
 * Simple CSS minifier.
 * Copyright (c) Mladen Mijatov, Way2CU
 */

// sample data
$data = <<<END

/**
 * Full blown comment.
 */
 
a.link + span:nth-of-type(3),
a.link ~ p,
footer div.form {
	position: relative;
	top: 0px;
	min-height: 700px;
	width: calc((100% - 1200px) / 2);
	
	/* inline comment */

	background-color: @color_background;
	background-image: url(../images/footer-background.jpg);
	background-position: top center;
	background-repeat: no-repeat;

	color: #ffbb00;
	color: rgba(0.0, 0.0, 0.0, 1);
}

END;

$data = preg_replace('/\/\*.*?(?=\*\/)\*\//imus', '', $data);
$data = preg_replace('/([^\d])-?(0+)(px|pt|rem|em|vw|vh|vmax|vmin|cm|mm|m\%)/imus', '\1\2', $data);
$data = preg_replace('/\s*([>~:;,\[\]\{\}])\s*/imus', '\1', $data);
$data = preg_replace('/\s*([\(\)])\s*([^+-\/\*\^])/imus', '\1\2', $data);
$data = preg_replace('/([\+])\s*([^\d])/imus', '\1\2', $data);
$data = preg_replace('/#([\dabcdef])\1([\dabcdef])\2([\dabcdef])\3/imus', '#\1\2\3', $data);
print preg_replace('/;\}/imus', '}', $data);