Echarts Tooltip display issue when html body is using css property zoom: 0.5

### Version
5.0.2

### Reproduction link
[https://jsfiddle.net/sr5o68yt/](https://jsfiddle.net/sr5o68yt/)

### Steps to reproduce
1. Click The Zoom 0.5 button
2. hover on the chart, you can see tooltip display issue.

### What is expected?
tooltip should work fine like when we don't zoom

### What is actually happening?
tooltip display error

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I tested, if i zoom browser in the settings, then everything works fine, but if we directly update the body css property zoom to 0.5, then this tooltip display issue occurs.