"Classical style" or "retro style"。
“古典风格”是"classical style" 。
“复古风格”是 "retro style"。
解释：
classical style
[词典] 古典风格;
[例句]From the classical style changes also was designed to extract concise wear fashionable for brides, provides many choices.
款式变化也从经典隆重设计中提炼出简洁易穿的时髦款，为新娘们提供了多多选择。
retro style
[词典] 复古风; 复古风格;
[例句]Taiwan kicked off the new year in retro style, with a bank run that looked more 1997 than 2007.
台湾似乎以一种复古方式开始新年：这里发生的银行挤兑事件，更像是在1997年，而非2007年。
梦溪shuer
