* Improve their accessibility by giving both links
a full label "Jump to x" and "Jump to y" instead
of "Jump to: ", "x", "y".
This also makes things much better for localisation, for which
we generally discourage use of concatenation.
* Use pure CSS for the toggling of the visibility on focus,
instead of relying on JavaScript. Especially given the
JS comes form core's 'jquery.mw-jump' module, which is
considered technical debt per T195256. Alternatively,
that could be copied to vector.js, but pure CSS
is possible, so why not.
* Use plain <a> links in the HTML instead of wrapped in a <div>.
This solves the long-standing problem whereby the margin
between #contentSub and #mw-content-text had to be awkwardly
negated and overridden in core and on various to make sure that
the wrapper itself would become visible as needed, in a way that
has margin around this. This whole problem doesn't apply when
simply using inline links that aren't part of the regular flow
with .mixin-screen-reader-text. On focus, the individually
focussed link appears in regular flow, without the need for
any custom styles.
* This uses :not(:focus) to naturally make it render in the default
way on focus, and visibibly hidden/clipped otherwise.
This is supported in IE9+ and Android 2+.
There is a way to make it work with CSS2 for IE7-8, by applying
the mixin to '.mw-jump-link' only and then undoing all of
'position', 'width', 'height', 'clip', and 'margin' on :focus.
But I'm not sure that's worth it here. The fallback in IE7-8
for not supporting ":not(:focus)" is that the accessibility
link is simply visible always, which seems like a good fallback
for accessibility, and doesn't hurt anything.
Bug: T195256
Change-Id: Icaadb290f692b3617688d32cbb66dfb007f1c82c
