themes/docsy/assets/scss/_search.scss

// Search

.td-search-input {
    background: transparent;

    &.form-control:focus {
        border-color: lighten($primary, 60%);
        box-shadow: 0 0 0 2px lighten($primary, 30%);
    }

    @if $enable-rounded {
        border-radius: 1rem;
    }

    font-family: "Font Awesome 5 Free", $font-family-base;
}