body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
}

#container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    margin: 20px;
}

#code-section, #output-section {
    margin: 20px;
    flex: 1 1 400px;
}

textarea {
    width: 100%;
    font-family: monospace;
}

#error {
    color: red;
    margin-top: 10px;
}

#output {
    margin-top: 20px;
}

#treeCanvas {
    border: 1px solid #000;
    margin-top: 20px;
    background-color: #ffffff;
}

#inputX.valid {
    outline: 2px solid green;
}

#inputX.partial {
    outline: 2px solid orange;
}

#inputX.invalid {
    outline: 2px solid red;
}