body {
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f0f0f0;
    margin: 0;
}

.container {
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    text-align: center;
}

h1 {
    margin-top: 0;
    color: #333;
}

.controls {
    margin-bottom: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    align-items: center;
}

.controls label {
    font-weight: bold;
}

.controls input[type="color"] {
    width: 40px;
    height: 30px;
    border: none;
    padding: 0;
    cursor: pointer;
}

.controls input[type="range"] {
    width: 100px;
}

.controls button {
    padding: 8px 15px;
    border: none;
    border-radius: 4px;
    background-color: #007bff;
    color: white;
    cursor: pointer;
    font-size: 1em;
}

.controls button:hover {
    background-color: #0056b3;
}

canvas {
    border: 1px solid #ccc;
    background-color: #fff;
    cursor: crosshair;
    display: block; /* canvasの下に余白ができないように */
    margin: 0 auto;
}