html部分

//HTML
<el-input class="input-item" v-model="formData.cInvoiceNo" size="mini" />

css部分

//CSS
.input-item>>>.el-input__inner{
  font-size: 12px!important;
  color:#333333!important;
  font-family:Roboto!important;
  font-weight: bold;
  padding: 0px!important;
}