body{margin:0}
textarea {
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
  position: absolute;
  width: 100%;
  height: 100px;
  outline: 0;
  padding: 1em;
  border: 0;
  font-size: 1.2em;
  resize: none;
  background:#fef;
}