JSFiddle - React, Tailwind, and code Playground

HTML

<div class="session-textchat">
  <div class="past-messages">
    <div class="receiver">
      <span class="message">
        Good afternoon David. Welcome to your appointment! How are you today?
      </span>
    </div>
    <div class="sender">
      <span class="message">
        Hello doctor. I feel terrible to be honest.
      </span>
    </div>
    <div class="receiver">
      <span class="message">
        I can see from your notes that you've been having some ear ache - can you tell me a bit more about your symptoms?
      </span>
    </div>
    <div class="sender">
      <span class="message">
        Hello doctor. I feel terrible to be honest.
      </span>
    </div>
    <div class="receiver">
      <span class="message">
        I can see from your notes that you've been having some ear ache - can you tell me a bit more about your symptoms?
      </span>
    </div>
  </div>
</div>

CSS

.session-textchat {
    height: 320px;
    background: #fff;
    display: -webkit-flex;
    display: flex;
    -webkit-align-items: flex-end;
    align-items: flex-end;
    -webkit-justify-content: space-between;
    justify-content: space-between;
    -webkit-flex-direction: column;
    flex-direction: column; 
}
.session-textchat .past-messages {
      width: 100%;
      max-width: 980px;
      margin: 0 auto;
      height: 83.92%;
      overflow-y: auto;
      padding: 30px 0 0;
      display: -webkit-flex;
      display: flex;
      -webkit-align-items: flex-end;
      align-items: flex-end;
      -webkit-justify-content: flex-end;
      justify-content: flex-end;
      -webkit-flex-direction: column;
      flex-direction: column; 
}
.session-textchat .past-messages .receiver,
.session-textchat .past-messages .sender {
        width: 100%;
        min-height: 47px;
        margin: 0 0 20px;
        display: -webkit-flex;
        display: flex;
        -webkit-flex-direction: row;
        flex-direction: row; 
}
.session-textchat .past-messages .receiver .message,
.session-textchat .past-messages .sender .message {
          position: relative;
          padding: 17px;
          -moz-border-radius: 4px;
          -webkit-border-radius: 4px;
          border-radius: 4px; 
}
.session-textchat .past-messages .receiver {
        text-align: left;
        -webkit-justify-content: flex-start;
        justify-content: flex-start; 
}
.session-textchat .past-messages .receiver .message {
          background: #f4f4f4;
          color: #535353; 
}
.session-textchat .past-messages .sender {
        text-align: right;
        -webkit-justify-content: flex-end;
        justify-content: flex-end; 
}
.session-textchat .past-messages .sender .message {
          background: url('../img/rgbapng/0050ff26.png');
          background: rgba(0, 80, 255, 0.15);
          color: #0050ff; 
}