html, body {
  display: flex;
  flex-direction: column;
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background: red;
}

textarea:focus {
  outline: none;
}

#toolbar {
  display: flex;
  align-items: center;
  gap: 20px;
  margin: 0;
  padding: 10px;
  background: #4A81E0;
  color: white;
}

#toolbar a {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: Helvetica;
  font-size: 24px;
}

#toolbar input {
  width: 60px;
}

#stack {
  position: relative;
  flex: 1;
}

#write, #read {
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0;
  padding: 5px;
  color: transparent;
  background: transparent;
  caret-color: black;

  white-space: pre; /* prevent wrapping */
  overflow-x: auto; /* allow horizontal scroll */
  overflow-y: auto; /* optional: vertical scroll */
  
  font-size: 20px;
  font-family: Helvetica;
  box-sizing: border-box;
  resize: none;
  border: none;
/*   text-decoration: none; */
}

#read {
  background: white;
  color: black;
  pointer-events: none; /* Optional: make read-only and unclickable */
  user-select: none;
}

.wrong {
  text-decoration: underline;
  text-decoration-style: wavy;
  text-decoration-color: red;
  text-decoration-skip-ink: none;
}