Which feature was common in japanese architecture during the heian period?

Simple designs showing harmony with nature

Explanation:

During the Heian period, the increasing size of buildings in the capital led to an architecture characterized by simple designs showing harmony with nature and dependent on regularly spaced columns.

The Shishinden Imperial Palace during this period demonstrated a style that was a precursor to the later aristocratic building style known as shinden-zukuri. The style was characterized by symmetrical constructions placed as arms that defined an inner garden. This garden then used a borrowed landscape to seemingly blend in with the larger landscape.

the factors that the economies of the muslim empires prosper were:

1- land trade routes-located between three continents  

2- sea trade routes

trade contributed to the spread of muslim empires, and with that islamic culture led to a growing feeling of internationalism resulted in the transfer of technology, science, and other cultural forms.