<div class="test">This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test This is a test </div>

html {
  height: 10px; /* ha ha only 10px tall */
  width: 100px;
  background: red; /* still fills the whole canvas though*/
}
body {
  background: yellow; /* won't propogate to html element because html's background is not transparent*/
  height: 100%; /* the yellow body is only 10px tall because html is only 10px tall*/
}

/* The text overflows the yellow background because the body is only 10px tall*/