dootask/resources/assets/sass/components/resize-line.scss

.component-resize-line {
    cursor: col-resize;

    &.resizing {
        &:after {
            content: '';
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            z-index: 99999;
            cursor: col-resize;
        }
    }

    &.bottom {
        cursor: row-resize;

        &:after {
            cursor: row-resize;
        }
    }
}

body.window-portrait {
    .component-resize-line {
        display: none;
    }
}