Everything an authorized php function may need to know about where it is being called from: the injected compilation context, the css selector currently being emitted, the compile-time scope and the source position (the spec, 48B.3).
readonly class MMO\client\scs\EvaluationContext
Namespace
MMO\client\scs
The selector is the **resolved** one: inside `.card { .title { padding: php::pad() } }` a context function
receives `.card .title`, not `.title`.