@Youtube 2013: Cinema + Assorted Tweaks
target site: youtube.com

v.1.00: Initial release. (2013-01-03)
v.1.01: minor fix: "All Comments" selector needed changing (2013-01-20)
v.1.02: outline like and dislike buttons
v.1.03
v.1.04: added selector for visitation
v.1.05: added selectors
v.1.06: selector alterations due to site changes (2013-03-20), kept old selectors as-is in case this doesn't apply to all users.
v.1.07: fix for embedded videos
v.1.08: fix author-viewing selector; added style to hidden/flagged comments
v.1.09: added selector for visitation
v.1.10: playlist tray, tray toggle button visibility; detach and float watchlist control panel.
v.1.11: playlist tray margin vs. video player.
v.1.12: squish troublesome sidebar some more; wider add-to-watchlist button on some feeds.
v.1.13: moved watch-later css rules to separate block to affect only certain pages.
v.1.14: detach and float playlist control panel
v.1.15: add-to panel fix; dismissed panel/slide is fully cleared after adding items to playlist.
v.1.16: Patched for Youtube layout changes made in August 2013. Not sure it it applies to everyone (beta status), so I'll leave to old css in there but disabled. (2013-08-09)
v.1.17: patch for -legacy IDs. (2013-08-15)
v.1.18: patch for youtube changes. (2014-02-21)
v.1.19: patch for html5 player (2014-02-22)
v.1.20: patch to fix sidebar positioning (2014-07-12)


notes:
* This style is for the new youtube layout introduced late 2012, which may or may not still be in beta or applicable for particular user.

css notes:
* Tweak #player-api #watch7-player #watch-video height rule as needed.
* Sometimes the playlist drop-box covers the video. This happens when the video player is in small mode (as indicated on the player itself by two boxes towards the right of the player controls, one small and one big), click the larger box to enlarge the player and the drop-box should either go away or become collapsible.