body {
  font-family: Arial, sans-serif;
  background: #f7f7f7;
  display: flex;
  justify-content: center;
  padding: 40px;
}

.container {
  background: white;
  padding: 20px;
  max-width: 800px;
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
  text-align: center;
}

textarea {
  width: 100%;
  height: 120px;
  margin-top: 10px;
  padding: 10px;
  font-size: 14px;
}

button {
  margin-top: 20px;
  padding: 10px 20px;
  font-size: 16px;
}

#diffResult {
  margin-top: 30px;
  text-align: left;
  white-space: pre-wrap;
  font-family: monospace;
}

.added {
  background-color: #d4f7d4;
}

.removed {
  background-color: #fddddd;
}