#output {
    background-color: #f4f4f4;
    border: 1px solid #ccc;
    border-radius: 4px;
    padding: 10px;
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: "Fira Code", "M PLUS 1 Code", monospace;
    font-size: 16px;
    line-height: 1.5;
}

#panel {
    margin: 10px 0;
}

.lambda-abs {
    padding: 5px 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    margin: 10px;
}

.lambda-abs::before {
    content: "λ";
    font-weight: bold;
    font-size: 1.5em;
    color: #000;
}

.variable {
    display: inline-flex;
    margin: 5px 0;
}

.variable > input {
    font-family: "Fira Code", "M PLUS 1 Code", monospace;
    font-weight: bold;
    font-size: 1.5em;
    margin: 0 10px;
    width: 3em;
}

.paren {
    border: 1px solid #ccc;
    border-radius: 4px;
    padding: 5px 10px;
    margin: 10px;
}

.paren::before {
    content: "(";
    font-weight: bold;
    font-size: 1.5em;
    color: #000;
    margin-right: 5px;
}

.paren::after {
    content: ")";
    font-weight: bold;
    font-size: 1.5em;
    color: #000;
    margin-left: 5px;
}

.button {
    display: inline-flex;
    font-family: "Fira Code", "M PLUS 1 Code", monospace;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1.5em;
}

.add-button {
    background-color: transparent;
    color: #888;
    border: 1px dashed #888;
}

.close-button {
    background-color: transparent;
    color: #888;
}