@syntax
On second thought you may not need to break #semanticHTML if your webpage container is after the #checkboxHack?
So in #SASS it might be (very roughly):
.themeSwitcher[:checked] + #webpageContainer {
// test for what
// @aymm
// mentioned and have styles
// accordingly?
}
Do a small test first, perhaps?
#semanticHTML #checkboxHack #sass #webpageContainer