Responsive HTML Buttons

ref: https://litmus.com/blog/a-guide-to-bulletproof-buttons-in-email-design

by Ian Roberts

HTML

<!-- https://litmus.com/blog/a-guide-to-bulletproof-buttons-in-email-design -->
<!-- -->
<br><p>
VML-BASED BUTTONS
</p>
<!-- vml approach -->
<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td>
      <div>
        <!--[if mso]>
          <v:roundrect xmlns:v="urn:schemas-microsoft-com:vml" xmlns:w="urn:schemas-microsoft-com:office:word" href="http://litmus.com" style="height:36px;v-text-anchor:middle;width:150px;" arcsize="5%" strokecolor="#EB7035" fillcolor="#EB7035">
            <w:anchorlock/>
            <center style="color:#ffffff;font-family:Helvetica, Arial,sans-serif;font-size:16px;">I am a button &rarr;</center>
          </v:roundrect>
        <![endif]-->
        <a href="http://buttons.cm" style="background-color:#EB7035;border:1px solid #EB7035;border-radius:3px;color:#ffffff;display:inline-block;font-family:sans-serif;font-size:16px;line-height:44px;text-align:center;text-decoration:none;width:150px;-webkit-text-size-adjust:none;mso-hide:all;">I am a button &rarr;</a>
      </div>
    </td>
  </tr>
</table>
<!-- -->
<br><p>
PADDING BASED BUTTONS
</p>
<!-- padding approach -->
<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td>
      <table border="0" cellspacing="0" cellpadding="0">
        <tr>
          <td bgcolor="#EB7035" style="padding: 12px 18px 12px 18px; border-radius:3px" align="center"><a href="http://litmus.com" target="_blank" style="font-size: 16px; font-family: Helvetica, Arial, sans-serif; font-weight: normal; color: #ffffff; text-decoration: none; display: inline-block;">I am a button &rarr;</a></td>
        </tr>
      </table>
    </td>
  </tr>
</table>
<!-- -->
<br><p>
BORDER BASED BUTTONS
</p>
<!-- border based buttons -->
<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td>
      <table border="0" cellspacing="0" cellpadding="0">
        <tr>
          <td>
            <a href="http://litmus.com" target="_blank" style="font-size: 16px;...