html, body {
    margin: 0;
    width: 100%;
    height: 100%;
}

.fullscreen {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;
    object-fit: cover;
    display: block;
}


#theButton {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 10;

    width: 20vw;
    height: 20vh;

    /* Center text vertically & horizontally */
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center; /* in case it wraps */

    /* Responsive font size */
    font-size: calc(1.8vh + 0.8vw);
    font-weight: bold;

    background: rgba(128, 128, 128, 0.5);
    color: white;

    border: none;
    border-radius: 12px;
    cursor: pointer;

    /* Blur background behind button */
    backdrop-filter: blur(4px);

    /* Smooth transitions for press effect */
    transition: transform 0.05s ease, background 0.05s ease;
}

/* Pressed / active state */
#theButton:active {
    transform: translate(-50%, -50%) scale(0.96);
    background: rgba(128, 128, 128, 0.7);
}