Css validator gave error for not allowed
<blockquote>
  <p>I am using validator.w3.org and got error. Why this error happened in
  css? Anybody have suggestion to remove this error.</p>
</blockquote>

<pre><code>Line 1, Column 1: character "*" not allowed in prolog

Line 20, Column 2: character "m" not allowed in prolog
**m**argin: 20px 0 0 20px;

Line 31, Column 2: character "b" not allowed in prolog
**b**ackground-image: -webkit-gradient(

Line 57, Column 1: character "{" not allowed in prolog

Line 113, Column 2: character "w" not allowed in prolog
width: 90px;

Line 133, Column 2: this is not an SGML document
</code></pre>