Selectize dropdown width independent of input

The widths of each label are set dynamically through JS. To overwrite that how about doing something like this:

.selectize-dropdown {
    width: 600px !important;
}

Fiddle

Robin's Answer didn't work for me. However the following did.

.selectize-input {
    min-width: 600px !important;
}

When the dropdown should change it's width dynamically to the largest option:

.selectize-dropdown {
  width: auto !important;
}

.selectize-dropdown [data-selectable], .selectize-dropdown .optgroup-header {
   white-space: nowrap;
}