// top-line
@mixin top-line {
    border: none;
    height: 42px;
    background-color: transparent;
    position: relative;
    cursor: pointer;
}

@mixin top-line-before {
    position: absolute;
    content:'';
    transition: all 0.25s;
    width: 20px;
    border: 0 solid transparent;
    top: -5px;
    left: 0px;
}

// bottom line
@mixin bottom-line {
    border: none;
    background-color: transparent;
    position: relative;
    cursor: pointer;
}

@mixin bottom-line-after {
    position: absolute;
    content:'';
    transition: all 0.25s;
    width: 20px;
    position:absolute;
    border: 0 solid transparent;
}

// both line
@mixin both-line {
    border: none;
    background-color: transparent;
    position: relative;
    cursor: pointer;
}

@mixin both-line-ab {
    content:'';
    transition: all 0.25s;
    width: 20px;
    position:absolute;
    border: 0 solid transparent;
}