Answers for "CSS style select> <option dropdown"

style a <select> dropdown

select {
   -webkit-appearance: none;
   -moz-appearance: none;
   appearance: none;
   background-image: url(...);
}
select::-ms-expand {
    display: none;
}
@media screen and (min-width:0) {
    select {
        background-image:none9;
        padding: 5px9;
    }
}

Select dropdown style

<select class="selectpicker">
  <option>Mustard</option>
  <option>Ketchup</option>
  <option>Relish</option>
</select>