body { margin: 0; color: #000; background-color: #eee; }
#hnmain { background-color: #fff; box-shadow: 0 0 6px rgba(0, 0, 0, .2) } /* Better colours */
.itemlist { padding-left: .5em; }
td { color: inherit; }
.togg { float: left; margin-right: .5em; } /* Collapse button to the left */
.comment { line-height: 1.4em; } /* Bit more line-height */
The thing I miss the most is the ability to clearly cite/quote things, whether it's other posts or something from an article. Yes, you can use ">", maybe wrapped in italics, but I find it pretty unclear, especially for longer texts. You can have some user CSS or whatnot to clarify that, but that won't work for the majority of folks reading your post.
