.gtinymce-modern-light .mce-container.mce-menubar.mce-toolbar.mce-first.mce-stack-layout-item {
    border: 1px solid #DADADA!important;
}

.gtinymce-modern-light .mce-toolbar-grp.mce-container.mce-panel.mce-stack-layout-item {
    border-left: 1px solid #DADADA!important;
    border-right: 1px solid #DADADA!important;
}

.gtinymce-modern-light .mce-statusbar.mce-container.mce-panel.mce-last.mce-stack-layout-item {
    border-bottom: 1px solid #DADADA!important;
    border-left: 1px solid #DADADA!important;
    border-right: 1px solid #DADADA!important;
}