Reply To: Full page width with left sidebar twentyfourteen

thanks bud

I had @import in my child theme

did as mentioned in

https://codex.wordpress.org/Child_Themes

put below code in style.css in child theme
———————————————–
#bbpress-forums {
font-size: inherit !important;
width: 100% !important;
}

@media screen and (min-width: 1008px)
.bbpress .site-content {
margin-right: 0 !important;
margin-left: 182px !important;
}

.bbpress .site-content {
margin-right: 0 !important;
margin-left: 0 !important;
}
———————————–
also copied page.php (from twentyfourteen folder) and renamed to bbpress.php put in root of child theme