body {
    font-family: Arial, sans-serif;
    background: #f5f5f5;
    padding: 20px;
    text-align: center;
}

h1 { margin-bottom: 20px; }

.controls {
    margin-bottom: 20px;
}

button {
    background: #4CAF50;
    padding: 6px 12px;
    border: none;
    color: white;
    border-radius: 5px;
    cursor: pointer;
    margin: 3px;
}

button:hover {
    opacity: 0.8;
}

.node {
    display: inline-block;
    background: rgb(233, 252, 255);
    padding: 10px;
    border-radius: 10px;
    border: 2px solid #ccc;
    margin: 10px;
}

.children {
    margin-left: 40px;
}

.node input {
    width: 200px;
    padding: 4px;
    margin-bottom: 5px;
}

.removeBtn {
    background: red !important;
}