alignright not working after import

I have just imported a load of posts into my WordPress install from a different website and alignright does not now work. Text is not wrapping around the thumbnails on the posts properly.

For example:

https://www.angelseo.co.uk/seo/business/mailchimp-sendy/

I have the following in my css and I have marked all as important, but although I can see (e.g. on Chrome inspect element) the style applies to the element, I don’t see anything under matched css rules.

img.centered, .aligncenter, div.aligncenter {
display: block  !important;
margin-left: auto  !important;
margin-right: auto  !important;
}

img.alignright {
padding: 4px  !important;
margin: 0 0 2px 7px  !important;
display: inline  !important;
}

img.alignleft {
padding: 4px  !important;
margin: 0 7px 2px 0  !important;
display: inline  !important;
}

.alignright {
float: right  !important;
}

.alignleft {
float: left  !important;
}

Would appreciate any help if anyone can think of something I could try!

Ty ??