.responsive-iframe {
    border: 0;  
    width: 100%;  
    height: 700px;  
    max-width: 100%;  
    margin: 0;  
    display: block;  
}

#feedback-container {
    max-width: 555px;
    min-width: 555px;
}

@media (max-width: 600px) {
  .responsive-iframe {
      height: 800px;
  }
  
#feedback-container {
      max-width: calc(100% - 85px);
      min-width: 250px;
  }
}