Changing 'Read' Link Boxes in Sidebar

Hi,

I would like to change the read boxes on the right hand sidebar. I would like them to work in the same way as the ‘older entries’ link for example, where it is grey text then transforms to a box when hovered over. Any ideas?

You can see the read box links on the right hand sidebar and also the older entries link at the bottom (above the footer) at: https://adastra-marketing.com/category/blog/

Thank you