I would guess maybe the selectors need a bit more specificity to override what is already being applied. For what it’s worth, this is my working CSS for the dropdown. Maybe you’ll find some useful
/* CHOSEN DROPDOWN */
.gform_wrapper .ginput_list .chosen-container {
font-size: inherit;
}
.gform_wrapper .chosen-container-single a.chosen-single {
color: var(--gravityforms-color-dark);
border: 2px solid var(--gravityforms-color-dark);
border-radius: 3px;
/* padding: 5px 10px; */
height: var(--gravityforms-field-general-height);
background: var(--gravityforms-color-lightest);
line-height: 1.5;
top: 2px;
box-shadow: none;
}
.gform_wrapper .chosen-container-single .chosen-single span {
margin: calc((var(--gravityforms-field-general-height) - (2 * var(--gravityforms-field-general-box-shadow-width)) - 1.5em) / 2);
color: var(--gravityforms-color-dark);
}
.gform_wrapper .chosen-container-single.chosen-container-active a.chosen-single {
border: 2px solid var(--gravityforms-color-dark);
background-color: var(--gravityforms-color-light);
outline: 0;
background-image: none;
box-shadow: none;
}
.gform_wrapper .chosen-container-single a.chosen-single>div {
display: none;
}
.gform_wrapper .chosen-container-single div.chosen-search input[type=text] {
background-color: var(--gravityforms-color-lightest);
background-image: none !important;
}
.gform_wrapper .chosen-container-single div.chosen-drop {
border: 2px solid var(--gravityforms-color-dark);
background-color: var(--gravityforms-color-light);
border-top: 0;
border-radius: 0 0 4px 4px;
}
.gform_wrapper .chosen-container ul.chosen-results li {
color: var(--gravityforms-color-medium);
}
.gform_wrapper .chosen-container ul.chosen-results li.highlighted {
background-color: var(--gravityforms-color-lightest);
background-image: none;
color: var(--gravityforms-color-accent);
}
.gform_wrapper .chosen-container-single a.chosen-single span:after,
.gform_wrapper .chosen-container-single.chosen-container-active a.chosen-single span:after,
.gform_wrapper .chosen-container-single div.chosen-search:after {
display: inline-block;
font-family: "Material Design Icons";
speak: none;
font-style: normal;
font-weight: normal;
font-variant: normal;
text-transform: none;
text-rendering: auto;
line-height: 1;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
}
.gform_wrapper .chosen-container-single a.chosen-single span:after {
content: '\f572';
position: absolute;
right: .75em;
font-size: 1.5em;
top: calc((var(--gravityforms-field-general-height) / 2) - .75rem);
}
.gform_wrapper .chosen-container-single.chosen-container-active a.chosen-single span:after {
content: '\f157';
}
.gform_wrapper .chosen-container-single div.chosen-search:after {
content: '\f349';
position: relative;
left: -2.25em;
}
.gf_simply_enhance_select .chosen-search {
display: none;
}
@media only screen and (max-width: 641px) {
.gform_wrapper.gf_browser_chrome .chosen-container-single .chosen-single, .gform_wrapper.gf_browser_gecko .chosen-container-single .chosen-single, .gform_wrapper.gf_browser_safari .chosen-container-single .chosen-single {
line-height: 2.25 !important;
}
.gform_wrapper.gf_browser_chrome .chosen-container-single .chosen-single span:after, .gform_wrapper.gf_browser_gecko .chosen-container-single .chosen-single span:after, .gform_wrapper.gf_browser_safari .chosen-container-single .chosen-single span:after {
top: 1em;
}
}