>>770
@-moz-document domain("2channeler.com") {
#main > div:nth-child(1){
height: えっくすpx !important;
}
#main > div:nth-child(1) > div:nth-child(1){
height: えっくすpx !important;
}
#main > div:nth-child(1) > div:nth-child(1) > div:nth-child(1){
height: えっくすpx !important;
}
#main > div:nth-child(1) > div:nth-child(1) > div:nth-child(3){
height: わいpx !important;
}
}

こんな感じか？
"えっくす"に好きな数字を"わい"には"えっくす-21"で