Border Help Options

[effeffioneh]

Hi all!

I just want to apologise in advance if this isn't the correct place to be asking such a question - I'm just a clueless gal looking for some advice!

I have no idea how to describe the problem I'm experiencing but I'll do every thing I can to explain it to the best of my ability: I'm having an issue with a Tumblr theme HTML where the page borders seem to be running through text.
I've had the same theme for a number of years now but Tumblr recently updated their encryption policies and in order for me to be able to customise my blog I had to replace all http urls with https ones, but doing so seems to have affected the way in which the page borders work. On my old blog (using the non-updated version of the theme) the borders seem to "hug" themselves to whatever text is inserted alongside them, but on my newer blog (using the updated theme) the borders just run straight through the text - is there any way of fixing this? In example, is there anything that I could add to the HTML to rectify the issue?
I'm afraid I don't have the knowledge to be able to add any complex to it; I can only edit what's in front of me so, any help would be greatly appreciated!

I realise that this will probably by very vague to anyone reading so, if you have any questions you'd like to ask for some clarification then by all means, please - ask away!
I'm happy to provide links to the HTML's and such; I've attached images to show what's happening, below.

Thank you in advance to anyone who responds!

How the border should look:

How it appears with the updated https: