Shiichan in different browsers

I normally use Firefox on Linux. Shiichan's font and colors are different in Chrome and Internet Explorer. Why does this site look so different in different browsers?

____ __________
\ \ \___ /___ /
 \ \ \|_ \ |_ \
 / / /__) |__) |
/_/_/____/____/
               
__ __________
\ \___ /___ /
 \ \|_ \ |_ \
 / /__) |__) |
/_/____/____/
             
__      _       _        
\ \  __| |_   _| |__  ___
 \ \/ _` | | | | '_ \/ __|
 / / (_| | |_| | |_) \__ \
/_/ \__,_|\__,_|_.__/|___/
                         
       _             /\__ 
 _ __ (_) ___ ___   |/\\ \
| '_ \| |/ __/ _ \ (_)  | |
| | | | | (_|  __/  _   | |
|_| |_|_|\___\___| (_)  | |
                       /_/