$grid-header-trigger-border: 
    $grid-column-header-border-width
    $grid-column-header-border-style
    $grid-header-border-color;

.#{$prefix}column-header-trigger {
    background-color: $grid-header-over-background-color;
    border-left: $grid-header-trigger-border;
}

@if $include-rtl {
    .#{$prefix}rtl.#{$prefix}column-header-trigger {
        border-right: $grid-header-trigger-border;
        border-left: 0;
    }
}

.#{$prefix}column-header-last {
    border-right-width: 0;
    .#{$prefix}column-header-over .#{$prefix}column-header-trigger {
        border-right: $grid-header-trigger-border;
    }
}

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

}

.#{$prefix}group-header {
    border-right-width: 0;
    &:after {
        content: '';
        width: $grid-column-header-border-width;
        height: 100%;
        background: $grid-header-border-color;
        position: absolute;
        right: 0;
        top: 0;
    }
}

@if $include-rtl {
    .#{$prefix}rtl.#{$prefix}group-header {
        border-left-width: 0;
        &:before {
            content: '';
            width: $grid-column-header-border-width;
            height: 100%;
            background: $grid-header-border-color;
            position: absolute;
            left: 0;
            top: 0;
        }
        &:after {
            width: 0;
        }
    }
}