(css)element中el-select下拉框整体样式修改

重点代码（颜色可行修改）

// 修改input默认值颜色 兼容其它主流浏览器
/deep/ input::-webkit-input-placeholder {
    color: rgba(255, 255, 255, 0.50);
}
/deep/ input::-moz-input-placeholder {
    color: rgba(255, 255, 255, 0.50);
}
/deep/ input::-ms-input-placeholder {
    color: rgba(255, 255, 255, 0.50);
}
// input框
/deep/ .el-select,
/deep/ .el-input,
/deep/ .el-input__inner {
    background-color: rgba(255, 255, 255, 0.04);
    color: rgba(255, 255, 255, 0.50);
    border: none; // 去掉边框
    // border-color: #XXXXXX // 默认边框的颜色
    text-align: left;
    border-radius: 4px;
}

// 选中时边框颜色
// /deep/ .el-input__inner:focus{
//     border-color: #XXXXXX;
// }

// 鼠标悬浮时 input框颜色
/deep/ .el-input__inner:hover{
    background-color: rgba(255, 255, 255, 0.12);
}

// input框 右侧的箭头
/deep/ .el-select .el-input .el-select__caret {
    color: rgba(255, 255, 255, 0.50);
}

// option选项 上面的箭头
/deep/ .el-popper[x-placement^="bottom"] .popper__arrow::after {
    border-bottom-color: rgba(43, 45, 55, 0.80);
    z-index: 9999;
}
/deep/ .popper__arrow {
    border: none;
}
// option选项 最外层
/deep/ .el-select-dropdown {
    border: none !important;
    background: rgba(43, 45, 55, 0.80) !important;
    z-index: 9999;
}
// option选项 文字样式
/deep/ .el-select-dropdown__item {
    color: rgba(255, 255, 255, 0.50) !important;
    z-index: 9999;
}
/deep/ .el-select-dropdown__item.selected span{
    color: rgba(255, 255, 255, 0.80) !important;
    z-index: 9999;
}
// 移入option选项 样式调整
/deep/ .el-select-dropdown__item.hover{
    background-color: rgba(255, 255, 255, 0.06);
    color: rgba(255, 255, 255, 0.80) !important;
    z-index: 9999;
}

// 下拉框垂直滚动条宽度
/deep/ .el-scrollbar__bar.is-vertical {
     width: 10px;
     top: 2px;
 }
// 下拉框最大高度
 /deep/ .el-select-dropdown__wrap {
     max-height: 200px;
 } 

解决参考：https://blog.csdn.net/qq_43432158/article/details/122497039