Prevent 100% width elements from overflowing the slider container due to margins

Hi, unfortunately with 100% width container, adding a margin will cause the container and its children to overflow their parent container... It's possible to see this happen if you put another element right next to the slider - it will overflow a few pixels on top of it.

The only two ways I know of to get around this problem is:
1. Using http://dev.w3.org/csswg/css-values/#calc-notation in order to set `width: calc(100%-10px)`
2. Adding an inner div to contain the children and then changing the original container's (the `slider`'s) margin to padding with `box-sizing: border-box`.

I opted for the second since it doesn't rely on calc... please let me know if this option would work for you.
Thanks!