Possible small improvements:
In the toolbar pulldown lists, the highlighted rows are difficult to see, at least on my display (thinkpad), when not looking under the right view angle. The blue background is too light:
In the continuation of Farhan's suggestion about buttons color, this is the same for the selection checkmark, the vivid blue of an unselected checkmark suggests a selected post until we see another unselected post with the same color, if it exists.
BTW, I don't like the vivid blue.
It looks aggressive, a more matte shade would be better for me. Eyes are attracted by the colon of blue arrows in a page with short posts:
Maybe something like that would be possible, given the other constraints:
Or maybe the good magenta omnipresent in aviation displays: