css21/syntax/signed-numbers-002.xht

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>CSS syntax: signed numbers</title>
<link rel="author" title="Bert Bos" href="mailto:bert@w3.org" />
<link rel="help" href="http://www.w3.org/TR/CSS2/syndata.html#numbers" />
<link rel="match" href="signed-numbers-001-ref.xht" />
<meta name="assert" content='Both integers and real numbers may immediately be preceded by a "-" or "+" to indicate the sign.' />
<style type="text/css">
  div {background: red; width: 20px; height: 100px}
  div div {background: green; height: 20px}
  .s1 {margin-left: + 30px}			/* Invalid */
  .s2 {margin-left: - 10px}			/* Invalid */
  .s3 {margin-left: -/**/10px}			/* Invalid */
  .s4 {margin-left: 30px; margin-left: +00px}	/* Valid */
  .s5 {margin-left: 30px; margin-left: -0.00px}	/* Valid */
</style>
</head>
<body>
  <p>This should show a tall green bar, and no red.</p>
  <div>
    <div class="s1"></div>
    <div class="s2"></div>
    <div class="s3"></div>
    <div class="s4"></div>
    <div class="s5"></div>
  </div>
</body>
</html>