title: Max-height: 0 not collapsing Div
body: <p>I would like my chat box to collapse when they touch the header of the chat, similar to facebook. I know that hide_wrapBox is correctly being added, but it doesn't set the height of its contained elements to a (collapsed) fixed height. In other words, the messages inside the chat box 
  disappear but the box still stands, where I'd prefer it to minimize.</p>
  
  <pre><code>     &lt;div id="messages-card-container" class="mdl-cell mdl-cell--12-col mdl-grid"&gt;
  
        &lt;!-- Messages container --&gt;
        &lt;div id="messages-card" style="display:none;" class="mdl-card mdl-shadow--2dp mdl-cell mdl-cell--12-col mdl-cell--6-col-tablet mdl-cell--6-col-desktop"&gt;
          &lt;div class="mdl-card__supporting-text mdl-color-text--grey-600"&gt;
  
            &lt;div id="convoHeader"&gt;HEADER&lt;/div&gt;
            &lt;div class="wrapBox"&gt;
            &lt;div id="messages"&gt;
              &lt;span id="message-filler"&gt;&lt;/span&gt;
            &lt;/div&gt;
            &lt;form id="message-form" action="#"&gt;
              &lt;div class="mdl-textfield mdl-js-textfield mdl-textfield--floating-label"&gt;
                &lt;input class="mdl-textfield__input" type="text" id="message" placeholder="Type a message..."&gt;
              &lt;/div&gt;
            &lt;/form&gt;
            &lt;form id="image-form" action="#"&gt;
              &lt;input id="mediaCapture" type="file" accept="image/*,capture=camera"&gt;
              &lt;button id="submitImage" title="Add an image" class="mdl-button mdl-js-button mdl-button--raised mdl-js-ripple-effect mdl-color--amber-400 mdl-color-text--white"&gt;
              &lt;/button&gt;
            &lt;/form&gt;
            &lt;/div&gt;
          &lt;/div&gt;
        &lt;/div&gt;
  
        &lt;div id="must-signin-snackbar" class="mdl-js-snackbar mdl-snackbar"&gt;
          &lt;div class="mdl-snackbar__text"&gt;&lt;/div&gt;
          &lt;button class="mdl-snackbar__action" type="button"&gt;&lt;/button&gt;
        &lt;/div&gt;
  
      &lt;/div&gt;
  </code></pre>
  
  <p>Jquery:</p>
  
  <pre><code>&lt;script&gt;
      $('#convoHeader').click(function(){
      if($('.wrapBox').is(":visible")){
          $('.wrapBox').hide();
          $('#messages').addClass('hide_wrapBox');
          console.log('you get here');
      }else{
          $('.wrapBox').show();
          $('#messages').removeClass('hide_wrapBox');
      }
  });
  &lt;/script&gt;
  </code></pre>
  
  <p>CSS:</p>
  
  <pre><code> .hide_wrapBox {
         max-height: 0;
          width: 5px;
          bottom:0;
          outline: 4px solid red;
      }
  
  #messages-card {
    float: right;
    z-index: 1;
    height: 400px;
    width: 300px;
    bottom: 0%;
    margin-top: 15px;
  }
  #messages-card-container {
    position: absolute;
    right:0;
    z-index: 1;
    height: 400px;
    bottom: 0%;
  }
  .mdl-layout__header-row span {
    margin-left: 15px;
    margin-top: 17px;
  }
  .mdl-grid {
    max-width: 1024px;
    margin: auto;
  }
  .material-icons {
    font-size: 36px;
    top: 8px;
    position: relative;
  }
  .mdl-layout__header-row {
    padding: 0;
    margin: 0 auto;
  }
  .mdl-card__supporting-text {
    position:relative;
    width: auto;
    height: 100%;
    padding-top: 0;
    padding-bottom: 0;
    box-shadow: 0px 0px 2px 2px #888888;
  }
  
  #convoHeader, innerHTML{
      position: relative;
      color: white;
  }
  
  #convoHeader{
     position:relative;
     background-color: #c4d8e2;
     padding-bottom: 6px;
  }
  
  #convoHeader: hover{
      cursor:pointer;
  }
  #messages {
    overflow-y: auto;
    margin-bottom: 10px;
    height: 270px;
    //outline: 2px solid red;
  }
  #message-filler {
    flex-grow: 1;
  }
  .message-container:first-of-type {
    border-top-width: 0;
  }
  .message-container {
    display: block;
    margin-top: 10px;
    border-top: 1px solid #f3f3f3;
    padding-top: 10px;
    opacity: 0;
    transition: opacity 1s ease-in-out;
  }
  .message-container.visible {
    opacity: 1;
  }
  .message-container .pic {
    background-image: url('/images/profile_placeholder.png');
    background-repeat: no-repeat;
    width: 30px;
    height: 30px;
    background-size: 30px;
    border-radius: 20px;
  }
  .message-container .spacing {
    display: table-cell;
    vertical-align: top;
  }
  .message-container .message {
    display: table-cell;
    width: calc(100% - 40px);
    padding: 5px 0 5px 10px;
    color: #666666;
  }
  .message-container .name {
    display: inline-block;
    width: 100%;
    padding-left: 40px;
    color: #bbb;
    font-style: italic;
    font-size: 12px;
    box-sizing: border-box;
  }
  #message-form {
    display: flex;
    flex-direction: row;
    float: left;
  }
  #image-form {
    display: flex;
    flex-direction: row;
    width: 48px;
    float: right;
  }
  #message-form .mdl-textfield {
    //width: 300px;
     position:absolute;
     bottom:0;
  }
  #message-form, input{
     width:295px;
     height:32px;
     font-size: 12px;
     position:absolute;
     bottom:0;
  }
  #message-form button, #image-form button {
    width: 100px;
    margin: 15px 0 0 10px;
  }
  .mdl-card {
    min-height: 0;
  }
  .mdl-card {
    background: linear-gradient(white, #f9f9f9);
    justify-content: space-between;
  }
  #user-container {
    position: absolute;
    display: flex;
    flex-direction: row;
    top: 22px;
    width: 100%;
    right: 0;
    padding-left: 10px;
    justify-content: flex-end;
    padding-right: 10px;
  }
  #user-container #user-pic {
    top: -3px;
    position: relative;
    display: inline-block;
    background-image: url('/images/profile_placeholder.png');
    background-repeat: no-repeat;
    width: 40px;
    height: 40px;
    background-size: 40px;
    border-radius: 20px;
  }
  #user-container #user-name {
    font-size: 16px;
    line-height: 36px;
    padding-right: 10px;
    padding-left: 20px;
  }
  #image-form #submitImage {
    width: auto;
    padding: 0 6px 0 1px;
    min-width: 0;
  }
  #image-form #submitImage .material-icons {
    top: -1px;
  }
  .message img {
    max-width: 300px;
    max-height: 200px;
  }
  #mediaCapture {
    display: none;
  }
  @media screen and (max-width: 610px) {
    header {
      height: 113px;
      padding-bottom: 80px !important;
    }
    #user-container {
      top: 72px;
      background-color: rgb(3,155,229);
      height: 38px;
      padding-top: 3px;
      padding-right: 2px;
    }
    #user-container #user-pic {
      top: 2px;
      width: 33px;
      height: 33px;
      background-size: 33px;
    }
  }
  .mdl-textfield__label:after {
    background-color: #0288D1;
  }
  .mdl-textfield--floating-label.is-focused .mdl-textfield__label {
    color: #0288D1;
  }
  .mdl-button .material-icons {
    top: -1px;
    margin-right: 5px;
  }
  </code></pre>