[Bug Report] Cascader component causes Popper to increase zindex at 110% of the page

[maczyt]

Element UI version

2.12.0

OS/Browsers version

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.75 Safari/537.36

Vue version

2.6.10

Reproduction Link

https://codepen.io/maczyt/pen/bGbOZKL

Steps to reproduce

点击input，显示popper，打开控制台，可以看到元素class="el-popper el-cascader__dropdown"到zindex一直在递增抖动

What is Expected?

不发生抖动，zindex不发生递增

What is actually happening?

发生抖动，zindex发生递增

[element-bot]

Translation of this issue:

Element UI version

2.12.0

OS/Browsers version

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) Apple WebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.75 Safari/537.36

Vue version

2.6.10

Reproduction Link

Https://codepen.io/maczyt/pen/bGbOZKL

Steps to reproduce

Click input, display popper, open the console, and you can see that the element class = "el-popper el-cascader__dropdown" to zindex has been increasing jitter

What is Expected?

Without jitter, zindex does not increase

What is actually happening?

Jitter occurs, zindex increases

[myMask]

Cn: 我也遇到了这种情况; En: Me too.

[wpbestway]

需要修改node_modules/element-ui/lib/cascader.js下的源码： 源码中搜索： Object(resizeevent["addResizeListener"])(this.$el, this.updateStyle); 改为： if (this.filterable) { Object(resizeevent["addResizeListener"])(this.$el, this.updateStyle); } bug原因：源码更新机制问题造成不停更新样式，这里需要增加一个判断即可

[yszzu1]

2.13.2 still has this issue.

The css top attribute is changing between 78px and 79px

[yszzu1]

the reason may be browser is zoomed as 96%, when zoomed 100%, it's no shake

[snowyYU]

2.15.1 版本还是有这个问题

[snowyYU]

It works well after add specific height to class, like below:

.el-input.el-input--small.el-input--suffix {
    height: 33px;
}

[aimiy]

this may works better

.el-input.el-input--small.el-input--suffix {
  input {
    min-height: 34px !important;
  }
}