fronend/scss/_bootstrapselect.scss

.bootstrap-select {
    box-shadow: none !important;
    border-bottom: 1px solid #ddd !important;
    @include border-radius(0);

    .dropdown-toggle {
        &:focus,
        &:active {
            outline: none !important;
        }
    }

    .bs-searchbox,
    .bs-actionsbox,
    .bs-donebutton {
        padding: 0 0 5px 0;
        border-bottom: 1px solid #e9e9e9;

        .form-control {
            @include border-radius(0);
            @include box-shadow(none !important);
            border: none;
            margin-left: 30px;
        }
    }

    .bs-searchbox {
        position: relative;

        &:after {
            content: '\E8B6';
            font-family: 'Material Icons';
            position: absolute;
            top: 0;
            left: 10px;
            font-size: 25px;
        }
    }

    ul.dropdown-menu {
        margin-top: 0 !important;
    }

    .dropdown-menu {
        li.selected {
            a {
                background-color: #eee !important;
                color: #555 !important;
            }
        }

        .active {
            a {
                background-color: transparent;
                color: #333 !important;
            }
        }

        .notify {
            background-color: #F44336 !important;
            color: #fff !important;
            border: none !important;
        }
    }
}

.bootstrap-select.btn-group.show-tick {
    .dropdown-menu {
        li.selected {
            a {
                span.check-mark {
                    margin-top: 9px;
                }
            }
        }
    }
}