body { 
    height: 100%; 
    min-height: 100%;
    position: relative;
}

mydiv { 
    height: 100%; 
    min-height: 100%; 
    position: absolute; 
    top: 0; 
    right: 0; 
    bottom: 0;
    width: 290px;
}

我读了很多答案，特别是这个(Prestaul答案)：
Setting 100% height on an absolutely positioned element when the content expands past the window size。

但对我来说这个伎俩不行，小提琴的例子也不行！

This is the jsfiddle working example.

This is the same code that doesn’t work.