I'm building a wordpress theme options page using the redux framework. I read al the data in my style.php file and i will include that file in de header so the custom css is loaded.

style.php:

<?php
?>
body {
    background-color:<?php global $variable; echo $variable['color-background'];?>;
    font-family:<?php global $variable; echo $variable['typography6']['font-family'];?>;
}

a {
    color: <?php global $variable; echo $variable['link-color']['regular'];?>;
}

<?php
?>

header.php:

<style>
<?php require_once('css/style.php');?>
</style>

Now its all messy in the head of my website. It would be great if it automatically generates a css file. Does anyone know a good option?

You can define your PHP file as a CSS file by writing header("Content-type: text/css"); at the start.

<?php
header("Content-type: text/css");
?>
body {
    background-color:<?php global $variable; echo $variable['color-background'];?>;
    font-family:<?php global $variable; echo $variable['typography6']['font-family'];?>;
}
...

If you do so you can link it with <link rel="stylesheet" type="text/css" href="css/style.php"> in header.php