html, body {
  margin: 0;     /* remove the default margin */
  height: 100%;  /* make the body fill the window */
}
canvas {
  width: 100%;    /* make the canvas fill the body */
  height: 100%; 
  display: block; /* make the canvas not cause a scrollbar */
}

.textarea {
  border: 1px solid rgb(203 213 225);
  border-radius: 0.25rem;
  height: 4rem;
  width: 90%;
}