Thanks for the updated CSS, it works on the latest build.
Strangely, this is not my experience on mobile at all. Maybe it’s because of my right-handed use, but I always found it much more difficult to tap on the topic title than on any other elements.
I mostly use my right thumb to navigate around and it’s almost impossible to accidentally tap category and even tags most of the time, but tapping on the title itself sometimes is (because of the left alignment of text and line breaking due to narrow screen width there is mostly negative space on the right).
Fortunately, Clickable Topic Theme Component vastly improved navigation on mobile for me, where I’m now almost exclusively using the negative space in the topic list to navigate to the topic itself, and use the category and tag elements to quickly filter to category or tag view (only to be surprised, again and again, that it doesn’t work 
).
I’m not sure if this is related to the screen size at all, but my mobile has a sub 6’’ screen and I never had any issues targeting those elements.
And when in the topic itself, there is even less spacing between the topic title and category and tag elements, and tapping them has alway been enabled there.