_sass/_typeahead.scss

//http://stackoverflow.com/questions/21749179/typeahead-js-v0-10-1-and-bootstrap-3/33177315#33177315
@mixin typeahead-active() {
    // mimics  @extend .dropdown-menu > .active > a;
    color: $dropdown-link-active-color;
    text-decoration: none;
    outline: 0;
    background-color: $dropdown-link-active-bg;
}

//https://github.com/corejavascript/typeahead.js/blob/master/doc/jquery_typeahead.md#class-names
span.twitter-typeahead {
    // this is the suggested matches dropdown
    .tt-menu {
        @extend .dropdown-menu;
    }

    .tt-hint {
        color: #999;
    }
    // Added to suggestion elements.
    .tt-suggestion {
        color: $navbar-default-color;

        // mimic .dropdown-menu > li > a
        padding: 3px 20px;
        line-height: $line-height-base;
        // Added to suggestion element when menu cursor moves to said suggestion.
        &.tt-cursor {
            @include typeahead-active;
        }
        // Hover/focus on suggestion
        &:focus,
        &:hover {
            @include typeahead-active;
        }

        p {
            margin: 0;
        }
    }

    .input-group & {
        display: block !important;

        .tt-dropdown-menu {
            top: 32px !important;
        }
    }

    .input-group.input-group-lg & {
        .tt-dropdown-menu {
            top: 44px !important;
        }
    }

    .input-group.input-group-sm & {
        .tt-dropdown-menu {
            top: 28px !important;
        }
    }
}