#ad-container, #show-ad-container {
    height: 100vh;
    width: 100vw;
    position: fixed;
    top: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.5);
    vertical-align: middle;
    opacity: 0;
}
.ad-content {
    width: 600px;
    height: 300px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}
.close-ad {
    color: #fff;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    text-align: center;
    line-height: 22px;
    background-color: rgba(0, 0, 0, 0.2);
    position: absolute;
    bottom: -40px;
    left: 48%;
    cursor: pointer;
}