gitbook/packages/gitbook-plugin-theme-default/less/Dropdown.less

.GitBook-Dropdown {
    display: inline-block;
    position: relative;
}

.GitBook-DropdownMenu {
    position: absolute;
    top: 100%;
    right: 0;
    z-index: 300;
    border: 1px solid @dropdown-border-color;
    margin: 5px;
    margin-top: 0px;
    border-radius: 3px;
    background: @dropdown-background;

    &:before {
        content: " ";
        width: 0;
        height: 0;
        border-left: @dropdown-arrow-width solid transparent;
        border-right: @dropdown-arrow-width solid transparent;
        border-bottom: @dropdown-arrow-width solid @dropdown-border-color;
        position: absolute;
        top: -@dropdown-arrow-width;
        right: 10px;
    }

    &:after {
        content: " ";
        width: 0;
        height: 0;
        border-left: (@dropdown-arrow-width - 1) solid transparent;
        border-right: (@dropdown-arrow-width - 1) solid transparent;
        border-bottom: (@dropdown-arrow-width - 1) solid @dropdown-background;
        position: absolute;
        top: -(@dropdown-arrow-width - 1);
        right: 11px;
    }
}

.GitBook-DropdownItem {
    padding: @dropdown-padding-v @dropdown-padding-h;
}

.GitBook-DropdownItemLink {
    width: 100%;
    display: inline-block;
    padding: @dropdown-padding-v @dropdown-padding-h;
    text-align: center;
    color: @dropdown-color;

    &:hover {
        color: @dropdown-hover-color;
    }
}