Android Wechat, select background color can not be removed?

wrote a simple h5 page, just a select,

select{
    font-size: inherit;
    color: inherit;
    font-style: inherit;
    font-weight: inherit;
    border: none;
    text-decoration: inherit;
    appearance: none;
    -moz-appearance: none;
    -webkit-appearance: none;
    box-shadow: none;
    outline: none;
    padding: inherit;
    margin: inherit;
    background: none;
    -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
    -webkit-tap-highlight-color: transparent;
}

<select class="no-style" style="font-size: 30px">
    <option value="123">123</option>
</select>

Why is there still a background color and how to remove it?

clipboard.png

clipboard.png

Css
Dec.04,2021

the general method is to hide the original one with display, then draw a new one with div+css, and then click to expand

using label.
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3efc1-2c485.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3efc1-2c485.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?