index.css

.y-select {
  display: inline-block;
}
.y-select_theme_normal {
  max-width: 100%;
}
.y-select_theme_normal .y-select__text{
  vertical-align: middle;
}
.y-select_theme_normal .y-select__text::after {
  content: '';
  display: inline-block;
  width: 11px;
  height: 6px;
  background: url("arrow.svg") no-repeat center;
  transition: transform 0.1s ease-out;
  vertical-align: middle;
  margin-left: 10px;
}
.y-select_theme_normal.y-select_size_s .y-select__text::after {
  width: 9px;
  height: 5px;
  background: url("arrow-s.svg") no-repeat center;
  margin-left: 6px;
}
.y-select_theme_normal.y-select_opened .y-select__text::after {
  transform: rotate(-180deg);
}
.y-select .y-select__popup {
    box-sizing: border-box;
    position: absolute;
    z-index: 32700;
    display: none;
    box-shadow: 0 10px 20px -4px rgba(0,0,0,.4);
    background-color: white;
    border: 1px solid rgba(0,0,0,.1);
    padding: 10px 6px;
    margin-top: 10px;
}
.y-select.y-select_opened .y-select__popup {
    display: block;
}
.y-select .y-select__option {
    cursor: pointer;
    padding: 0 20px 0 34px;
    font-size: 15px;
    line-height: 28px;
}
.y-select .y-select__option:not(.y-select__option_selected):hover::before {
    position: absolute;
    margin-left: -20px;
    width: 1em;
    content: '✓';
    color: #eaeaea;
}
.y-select .y-select__option.y-select__option_selected::before {
    position: absolute;
    margin-left: -20px;
    width: 1em;
    content: '✓';
}