outlook.com only prefixes first selector in a chain of selectors

[theotherstevenc]

It's widely known that outlook.com uses _x as a prefix for any class and id selectors. However, only the first selector included in a chain of selectors is correctly prefixed.

Double Example

.foo.bar { background:green; }

becomes:

.x_foo.bar { background:green; }

The expected outcome would be:

.x_foo.x_bar { background:green; }

Triple Example

.foo.bar.quo { background:green; }

becomes:

.x_foo.bar.quo { background:green; }

The expected outcome would be:

.x_foo.x_bar.x_quo { background:green; }

[theotherstevenc]

Gave this another test today. It is still an active issue within Outlook webmail.

iOS Outlook app is not affected

[husseinalhammad]

This has been reported on Outlook.com's uservoice in 2019. You can vote on here: https://outlook.uservoice.com/forums/601444-the-new-outlook-com/suggestions/38032228-bug-parsing-css-rule-with-multiple-classes-for-a-e