body {
    background-color: black;
    margin: 0;
    padding: 0;
    overflow: hidden; /* Prevent scrolling on mobile */
}

canvas {
    width: 100%;
    height: calc(100vh - 50px); /* Account for button height on mobile */
    position: relative;
    display: block;
    top: 0;
    transition: background-color 3.5s ease;
    margin: 0 auto;
}

@keyframes changeBrightness {
    0% { filter: brightness(1); }
    50% { filter: brightness(2); }
    100% { filter: brightness(1); }
}

.change-brightness {
    animation: changeBrightness 60s infinite;
}

button {
    position: fixed;
    bottom: 10px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 18px;
    padding: 10px 20px;
    background-color: #444;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    z-index: 10;
}

button:focus {
    outline: none;
}