index-css.css

.hide {
    opacity: 0.1;
    pointer-events: none;
}



.start-Game-container {
    position: absolute;
    width: 3em;
    height: 1.5em;
    font-size: 2em;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    margin: auto;
    white-space: nowrap;
    cursor: pointer;
    user-select: none;
    transition: all 100ms;
    background-color: aqua;
    border-radius: 7px;
    color: blueviolet;
    border: 1px solid blueviolet;
}

.box {
    width: 3em;
    height: 3em;
    background-color: #a11;
    position: absolute;
    left: 10%;
    top: 10%;
    border-radius: 50px;
    cursor: pointer;
    transition: opacity 100ms, transform 100ms;
}

.box.hide {
    transform: scale(0.2);
}