sticky

[1] Sticky Positioning ( (Edward O'Connor 著, 6/26/2012, 11:50:51 PM 版)) http://lists.w3.org/Archives/Public/www-style/2012Jun/0627.html

[2] Add renotify, silent, noscreen and sticky as attributes. · a6ec581 · whatwg/notifications (2/28/2015, 2:31:24 AM 版) https://github.com/whatwg/notifications/commit/a6ec581bfb32d5e66a892ca74544a9f9c129d48e

[3] Safari 7.0 (11/4/2015, 2:08:38 PM 版) https://developer.apple.com/library/safari/releasenotes/General/WhatsNewInSafari/Articles/Safari_7_0.html#//apple_ref/doc/uid/TP40014305-CH5-SW23

The new CSS property value position:-webkit-sticky allows a page element to implement “sticky” scrolling behavior, constrained by the page’s viewport or a scrollable ancestor, without resorting to asynchronous JavaScript scroll events that can interfere with smooth scrolling.

[4] Remove sticky and screen off features (annevk著, 11/4/2016, 10:38:50 AM) https://github.com/whatwg/notifications/commit/9a63989a0906d7191a11d637064b06bfaee31b09

[5] position:sticky is back in Chrome | Web | Google Developers (12/21/2016, 3:35:52 PM) https://developers.google.com/web/updates/2016/12/position-sticky

[6] Performant Parallaxing | Web | Google Developers (12/21/2016, 3:35:53 PM) https://developers.google.com/web/updates/2016/12/performant-parallaxing

[7] An event for CSS position:sticky | Web | Google Developers (9/27/2017, 4:21:07 PM) https://developers.google.com/web/updates/2017/09/sticky-headers

[8] thead や tfoot で上下に固定はできますけれども、左右それぞれ複数個のこまを固定したいときはこまをグループ化する方法がないのでちょっと面倒ですね。