.embed-container { 
  position: relative; 
  padding-bottom: 56.25%;
  overflow: hidden;
  max-width: 100%;
  height: auto;
} 

.embed-container iframe,
.embed-container object,
.embed-container embed { 
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}