how can I use two css files in one html/php page to style two div sections eg:

Question

<div id="one" >use a different css file </div>
<div id="two" >use a different css file </div>

Answer 1

Just import both via style-tag in header. As long as you didn't specify any conflicts, the browser will find the correct definitions in both files.

Answer 2

Nothing to add to Sandra's answer, no problem since you refer them without same informations

Answer 3

Import both the files using link tag in header for example
Style.css has the styles of Id #one and two.css has styles of Id #two
Then import them as
<link rel="stylesheet" type="text/css" href="style.css">
<link rel="stylesheet" type="text/css" href="two.css">