Squarespace Breakpoints.

squarespaceBreakpoints.less

/**
Squarespace essentially doesn't really document their breakpoints.
This can be quite annoying to not have when  doing custom CSS.

Most themes use essentially one breakpoint. Mobile and not mobile; anything 750 and below is considered mobile.

You can use these to write your own CSS and simply use the "Style Editor" to inject your compiled CSS in the event 
you are not using "Developer Mode" in your site.

Enjoy!
*/
@mobile:          ~"only screen and (max-width: 750px)";
@tablet:          ~"only screen and (min-width: 751px)";
@tablet-strict:   ~"only screen and (min-width: 751px) and (max-width: 949px)";
@tablet-desktop:  ~"only screen and (min-width: 751px)";
@desktop:         ~"only screen and (min-width: 950px)";
@desktop-strict:  ~"only screen and (min-width: 950px) and (max-width: 1199px)";
@desktop-xl:      ~"only screen and (min-width: 1200px)";

// Usage
@media @mobile {
  // Code here
}

@media @tablet-strict {
  // Code here
}

@media @desktop {
  // Code here
}

Thank you