Getting my home page widget area to correct width

Hi,

I have been struggling with this for a few weeks now although have made a bit of progress.

I am trying to put a Widget Area under the You Tube embedded video, but the area is only 76px wide instead of 300 so the widget area is all squashed up to the left.

I am using a child class and have added a widget area but when I take the area above
media=”all”
.col-300 {
width: 31.914894%;
}

it disappears to the bottom of the screen.

Any help would be very well received.

regards
Alig