Even smaller; there was an 11" Macbook Air discontinued in 2016. It was too slow for me, but I really like the form factor. Would like to see that return with AS.
Here are their sizes for comparison:
MacBook Air 11" 300 mm x 192 mm x 17 mm 1,08kg
MacBook 12" 280,4 mm x 196,6 mm x 13,2 mm 0,92kg