.invisible {
    border: 0;
    clip: rect(0 0 0 0);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}

.hidden {
    display: none !important;
}

.unselectable {
    -moz-user-select: none;
    -webkit-user-select: none;
    -ms-user-select: none;
    user-select: none;
    -webkit-touch-callout: none;
}

.float_left {
    float: left;
}

.float_right {
    float: right;
}

.clear {
    clear: both;
    height: 0.1px;
    line-height: 0.1px;
    font-size: 0.1px;
}

.cf {
    &::before,
    &::after {
        content: " ";
        display: table;
    }

    &::after {
        clear: both;
    }
}