style.css

.message_to_client, .message_to_admin {
    border: none;
    border-radius: 8px;
    margin: 10px 0px;
    padding:0px 5px 0px 5px;
}

.message_to_client {
    /*color: #ffffff;
    background-color: #297FB8;*/
    width: 55%;
    color: #fff;
    background-color: #00529B;
}

.message_to_admin { 
    /*color: #000000;
    background-color: #C5C5C5;*/
    margin-left: 35%;
    color: #282828; background-color: #d4d4d4; border-color: #d4d4d4;
}

.message_to_admin_date, .message_to_client_date {
    text-align: right;
    font-size: 0.7em;
    color: white;
}

.btn {
  background: #3498db;
  background-image: -webkit-linear-gradient(top, #3498db, #2980b9);
  background-image: -moz-linear-gradient(top, #3498db, #2980b9);
  background-image: -ms-linear-gradient(top, #3498db, #2980b9);
  background-image: -o-linear-gradient(top, #3498db, #2980b9);
  background-image: linear-gradient(to bottom, #3498db, #2980b9);
  -webkit-border-radius: 28;
  -moz-border-radius: 28;
  border-radius: 28px;
  font-family: Arial;
  color: #ffffff;
  font-size: 16px;
  padding: 10px 20px 10px 20px;
  text-decoration: none;
  cursor: pointer;
}

.btn:hover {
  background: #3cb0fd;
  background-image: -webkit-linear-gradient(top, #3cb0fd, #3498db);
  background-image: -moz-linear-gradient(top, #3cb0fd, #3498db);
  background-image: -ms-linear-gradient(top, #3cb0fd, #3498db);
  background-image: -o-linear-gradient(top, #3cb0fd, #3498db);
  background-image: linear-gradient(to bottom, #3cb0fd, #3498db);
  text-decoration: none;
  cursor: pointer;
}

#admin_message_content {
    clear: both;
    padding: 5px 5px 5px 5px;
    background-color: white;
    overflow-y: scroll;
    height: 400px;
}