#canvas {
    position: absolute;
    background: black;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

body {
    user-select: none; /* テキスト選択を無効化 */
}

.controls {
    position: fixed;
    top: 10px;
    left: 10px;
    background-color: rgba(255, 255, 255, 0.7);
    padding: 10px;
    border-radius: 5px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
button {
    padding: 10px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}
button:hover {
    background-color: #45a049;
}