Sending emails to Microsoft teams channel does not keep css format

I set up a channel where I sent an email with a specific css. In outlook I can see the message perfectly, but the channel does not display any colour. I even added the css with classes and id tags into the html file, but it does not work.

Example: The message is something like:

<html>
   <head>
    <script src= 'https://statics.teams.cdn.office.net/sdk/v1.6.0/js/MicrosoftTeams.min.js'></script>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <style type="text/css">
    #first{ color: orange; }
    #secondLine {
      background-color: lightblue;
      color: red;
    }
    .override {color: green;}
    </style>
   </head>
   <body>
      <script>
    microsoftTeams.initialize();
      </script>
      <p class="override">Hi there,</p>
      <p id="first"> First line:test.</p>
      <p id="secondLine">Second line Another test.</p>
      <p style="color:blue">Best Regards.</p>
   </body>
</html>

In outlook:

In Microsoft Teams channel:

I think that maybe it can not display the colour due to a css conflict with Microsoft teams css. If it is the case, could I override it?

Thank you in advance.