.iframe-container {
    position: relative;
    width: 80%;            
    max-width: 800px;      
    padding-bottom: 45%;   
    height: 0;
   
}

.iframe-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}