el-input-number添加自定义内容class-unit

在el-input,el-input-number中有需要在输入框后面添加单位的需求，这时候就需要用到class-unit

<el-input-number size="small" class-unit="%" class="inputNumberClass"></el-input-number>// css
.inputNumberClass[class-unit] {--el-input-number-unit-offset-x: 35px;position: relative;
}
.inputNumberClass[class-unit]::after {content: attr(class-unit);height: 100%;display: flex;align-items: center;position: absolute;top: 0;right: var(--el-input-number-unit-offset-x);color: #999999;
}
.inputNumberClass[class-unit] .el-input__inner {padding-left: 30px;padding-right: calc(var(--el-input-number-unit-offset-x) + 12px);
}