wagtail/client/scss/components/_dropdown.scss

// =============================================================================
// Listing view smaller dropdowns
// =============================================================================

// .c-dropdown {
// }
.c-dropdown__button {
    display: inline-block;
    box-sizing: border-box;
    padding-left: 0.5rem;
    padding-right: 0.25rem;
    // Make this the same as the other buttons
    line-height: 1.85;
    border: solid 1px transparent;
    border-radius: 2px;
    font-size: 0.95em;
    cursor: pointer;
    -webkit-font-smoothing: subpixel-antialiased;
    user-select: none;
}

.c-dropdown__toggle {
    display: inline-block;
}

.c-dropdown__togle--icon {
    &:before {
        display: none; // TODO: remove when iconfont styles are removed
    }

    .icon {
        @include svg-icon(1em, middle);
    }

    .icon-arrow-up {
        display: none;
    }
}

.is-open .c-dropdown__togle--icon {
    .icon-arrow-up {
        display: inline-block;
    }

    .icon-arrow-down {
        display: none;
    }
}

.c-dropdown__menu.c-dropdown__menu {
    margin-top: 0.75rem;
    padding: 0.75rem 1rem;
    min-width: 8rem;
    text-transform: none;
    position: absolute;
    z-index: 1;
    animation: dropdownIn 0.1s ease-out backwards;
    list-style: none;
}

.c-dropdown__item {
    margin-bottom: 0.375rem;

    &:hover {
        .c-dropdown__indicator {
            opacity: 0.6;
        }
    }
}

.c-dropdown__item:last-child {
    margin-bottom: 0;
}

.c-dropdown__divider {
    border-color: #555;
    border-style: dotted;
    margin-top: 12px;
    margin-bottom: 12px;
}

@keyframes dropdownIn {
    0% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}