The modal container's width can be adjusted by the width prop. The default is set to optimal. Width Options

Full This is a modal set to full width.	This is taking up the full width of the screen minus the gutters (about 2rem on left and right).
Regular This is a modal set to regular width.	This is 10 out 12 columns wide, about 80% of the screen width.
Optimal This is a modal set to optimal width.	This is about 75 characters wide, close to optimal reading length.
Auto This is a modal set to auto width.	This adjusts to the width of the modal content. In most cases, the user must define a max-width in absolute value (do not use relative value such as %) on the modal content to get the desired results. Recommended for advanced usage.
Additional Notes: this prop only applies to viewports equal to or above the small breakpoint (~600px).