.#{$prefix}column-header-trigger {
    width: 18px;
    background-image: url(images/grid/hd-pop.png);
    background-position: center center;
    border-left: 1px solid $grid-header-border-color;
}
// In RTL, trigger's border is on the right.
@if $include-rtl {
    .#{$prefix}rtl.#{$prefix}column-header-trigger {
        border-right: 1px solid $grid-header-border-color;
        border-left: 0 none;
    }
}

// Neptune grid header menu trigger is not background colour
.#{$prefix}column-header-trigger {
    background-color: $grid-header-over-background-color;
}

// While menu open, header and trigger go darker
.#{$prefix}column-header-open {
    background-color: $grid-header-over-background-color;
}

.#{$prefix}column-header-open .#{$prefix}column-header-trigger {
    background-color: mix($base-light-color, $neutral-light-color, 30%);
}

// Background colour for sorted state
.#{$prefix}column-header-sort-ASC,
.#{$prefix}column-header-sort-DESC {
    background-color: $sorted-grid-column-header-color;
}

// Neptune checkbox header has no visible border - make it background color
.#{$prefix}column-header-checkbox {
    border-right-color: $grid-header-background-color;
}
// In RTL, do that on the left
@if $include-rtl {
    .#{$prefix}rtl.#{$prefix}column-header-checkbox {
        border-right: 0 none;
        border-left-color: $grid-header-background-color;
    }
}

.#{$prefix}column-header-last {
    border-right: 0;
    .#{$prefix}column-header-over .#{$prefix}column-header-trigger {
        border-right: 1px solid $grid-header-border-color;
    }
}

@if $include-rtl {
    .#{$prefix}rtl.#{$prefix}column-header-last {
        border-left: 0;
        .#{$prefix}column-header-over .#{$prefix}column-header-trigger {
            border-left: 1px solid $grid-header-border-color;
        }
    }
}