Setting Right Sidebar Width Independantly

I’m trying to increase the width of just the right sidebar in the Travel Blogger theme (I posted this question to them but got no response). Their theme provides a tool for increasing both sidebars, so that doesn’t help. I’ve also tried working on the CSS and got things to move around a bit, but got ugly quick. I’m wondering if anyone with more CSS knowledge could take a quick look and suggest how I could increase the right sidebar width (the overall width will have to be increased so as not to shrink the main content width).

The site is tall.life

Thank you kindly,
Sam