The title attribute doesn’t provide enough accessibility for the link. You should have actual text inside the
<a> for the screen reader to read. The good news is that you can visually hide that text so it isn’t seen on the page.
One of the goals of responsive design is to adjust the layout to the amount of horizontal room you have. When you don’t have a lot of horizontal room you should try to maximize your use of the space in order to fit your content as nicely as possible. When I narrow my browser as skinny as it will go your quote box is only taking up around 50% of the horizontal space. To me this seems like a lot of wasted space that could be used by the quote box to allow the lines of text to be wider (i.e. maximize the amount of limited horizontal space). This is especially noticeable if you manually increase the font size a little. The other thing I would recommend is that with narrow view ports you also decrease the line height so the quote box doesn’t stretch as tall. Actually, I think your line height is too big even at a wider browser width.
If you don’t know how to manually increase the text size, using Firefox go to the ‘View-Zoom’ menu and activate ‘Zoom Text Only’. Then while holding down the Ctrl key scroll your middle mouse button to change the text size.