#contenedor-slideshow {
    width: 100%;
    max-width: 800px;
    margin: 20px auto;
    border: 10px solid #fff;
    box-shadow: 0 0 10px rgba(0,0,0,0.5);
    overflow: hidden;
    position: relative;
}

#contenedor-slideshow img {
    width: 100%;
    height: auto;
    display: block;
}