Css – change the appearance of react dropdown datepick

Hi I use to set the date the package react-dropdown-date. I want to change the background color when selecting the year. Unfortunately this does not work. I don’t know why. If I simply change option, then the change is applied, but with option:hover it is ignored.

import { React, useState } from "react";
import { YearPicker, MonthPicker, DayPicker } from "react-dropdown-date";
import "./Datum.css";

function DatumElement() {
  var [datum, setDatum] = useState({
    year: null,
    month: null,
    day: null,
  });

  return (
    <div className="datumContainer">
      <YearPicker
        className="datum"
        defaultValue={"select year"}
        start={1970} // default is 1900
        end={2020} // default is current year
        reverse // default is ASCENDING
        onChange={(year) => {
          // mandatory
          this.setDatum({ ...datum, year: year });
        }}
      />
    </div>
  );
}

export default DatumElement;

.datumContainer{
    display:flex;
    flex-direction:row;
    justify-content: flex start;
    gap:2vw

}

select {

    height:1.5vw;
    width:5vw;
    font-size:0.8vw;
    border:none;
    border-radius:20px;
    font-family: 'Sunflower', sans-serif;
    font-weight: 900;
}

option:hover{
    background-color: red;
}

I tried to find documentation about the package and tested how to change the tag options