But my own worry today is less that of the overwhelming problem of elemenal literacy than it is of the slightly more luxurious problem of decline in the skill even of the middle class reader.
请问这里less than 是什么句型吗，意思是什么?
1. But my own worry today is less that of the overwhelming problem of elemental literacy than it is of the slightly more luxurious problem of the decline in the skill even of he middle-class reader。
参考译文：但比起基础读写能力不足这一常见问题，我更担忧的是一个看着不那样紧迫的问题，即中产阶层读者的读写方法甚至也有所降低.
结构剖析：but my own worry is less that of...than it is of..., 用了比较特殊的比较级结构，be less that of sth than it is of sth。
