<!doctype html> <html> <head> <style> #container { height: 300px; width: 300px; overflow:hidden; border-radius:30px; opacity: 0.6; } #inner { width: 380px; height: 260px; background-color: #00ff00; } </style> </head> <body> <div id="container"> <div id="inner"> </div> </div> </body> </html>