Playing with columns width in Reddle

Hi,

I am using Reddle theme on my blog ( https://amardeepsidhu.com/blog )

I have been trying to increase the width of main column, decrease the width of 2nd column and reduce the margin on left and right sides of the main column. I played with few values and have been able to achieve some success.

Need your advice in decreasing the margin on left and right of the main columns. How can i do that ?

Also all the percentage values mentioned in style.css are pretty weird like 12.464285714286. Can i keep it simple like 12,15…or there is some specific reason why the width is divided into some weird percentages ?

Thanks,
Amardeep