.custom-combobox {
  position: relative;
  display: inline-block;
  width:100%;
  box-sizing: border-box;
}
.custom-combobox-toggle {
  position    : absolute;
  top         : 0;
  bottom      : 0;
  right       : 0;
  margin-left : 0;
  padding     : 0;
}
.custom-combobox-input {
  margin: 0;
  width: 100%;
}