Under Microsoft browsers IE9, IE10, IE11 & Edge, the .CSS definitions dealing with the //font-size// -to- //line-height// attribute relationship, when set by using relative unit values (em, rem) with a precision of more than two (//e.g.// `0.8750em`), are automatically rounded to only 2 digits after the decimal point (//e.g.// `0.87em`). This is by design **[[https://connect.microsoft.com/IE/feedback/details/816709/|according to Microsoft themselves]]**.
In a nutshell - For wiki-Foundation visitors using the affected Microsoft browsers, this means the expected Vector [__calculated__] defaults resulting in a //font-size// of 14px (16 × 0.8750 = 14) and a //line-height// of 22.4px (14 × 1.6 = 22.4) are actually rendering a //font-size// of 13.93px (16 × 0.87 = 13.93) and a //line-height// of 22.28px (13.93 × 1.6 = 22.28) for starters. Plus, any .css selectors that are calculated &/or defined based on &/or inherited from the current defined entry (illustrated above) will also be increasingly "off" compared to non-Microsoft browser users.
A simple change in the current Vector stylesheet should both begin to address this bug for IE 9, 10, 11 & Edge users while continuing the current "support" for [as far as I've tested] IE8 at the minimum. Applying the "workaround" might even rectify all sorts of reported "mis-alignments" & such for affected users
``` lang=css, name=current, lines=4
.mw-body-content {
position: relative;
font-size: 0.8750em;
line-height: 1.6;
z-index: 0;
}
```
``` lang=css, name=proposed, lines=4
.mw-body-content {
position: relative;
font-size: 0.8750em;
font-size: calc(1.00em * 0.8750);
line-height: 1.6;
z-index: 0;
}
```
**Version:** 1.26+