Add padding around rendered fenced code and change theme

[samgurung]

In the markdown.php config file i have set this in the extensions

'extensions' => [
        League\CommonMark\Extension\CommonMark\CommonMarkCoreExtension::class,
        League\CommonMark\Extension\Table\TableExtension::class,
        League\CommonMark\Extension\DisallowedRawHtml\DisallowedRawHtmlExtension::class,
        League\CommonMark\Extension\Table\TableExtension::class,
        League\CommonMark\Extension\Attributes\AttributesExtension::class,
        Spatie\CommonMarkShikiHighlighter\HighlightCodeExtension::class,
    ],

any code in my markdown is highigted. However i want to add some padding and margin to the rendered code. How do i do that. Also how do i specify a different theme the HighlightCodeExtension