Style issues after enabling Hummingbird

I have enabled hummingbird plugin on my test webiste(https://testing.bilingualnews.jp/) and its disabling the styles. For eg. The top and bootom navigation links are in bold. My live site its working fine – https://bilingualnews.jp/ but its not working in my testsite. Also the buutons in the shop pages’ styles also have some style issues.

How to fix the style issues after enabling the plugin. Please help me to resolve this.

The page I need help with: [log in to see the link]