How can I change the width of the right column block area?

Hi. All columns have fixed width. If you want to enlarge the main content area, you'll have to turn off right or left column.

I do it by changing the following css code lines in theme/summertime/style.css

.column-center{
width: 71.5%;
float: left;
overflow: hidden;
border-right: 1px solid #BAD4A7;

and

.column-right{
width: 26%;
border-left:1px solid #BAD4A7;
padding:20px 0 0 13px;
float: left;
margin-left:-1px;
overflow: hidden;

Just change percentage in both widths, e.g. if you want to increase center column width by 10%, add 10% to the existing value (so it will be 81.5%) and subtract 10% from the column-right width (so it will be 16%).

Then to e.g. center the text in column-right change the last value of padding in column-right (at the moment set to 13px)

ps. I am using version 6.x-1.4 so not sure if it will work for 1.2