How to reduce the width of the left side bar

Add this as custom css to reduce it to same width as the right sidebar:

.col-3cm .main-inner { background-position: -80px 0; padding-left: 260px; }
.col-3cm .s1 { width: 260px; margin-left: -260px; }

Added this to child css but there is no changes.
Will you please have a look? link

Looks correct to me, smaller sidebar on the left now than normal.

Okay but Can I make the 260px lesser. for that should I change something else as well?

Just adjust the 260px code values in the code as you wish, and you can. You also need to increase the -80px as much as you decrease the width.

Excellent.

Thank you so much for the help. ??