I am having trouble centering a button that I built inside a table. The CSS doesn't seem to be correct and I can't figure out why. I would appreciate any help with this issue. Additionally, the button needs to be displayed in an email, in case that affects the solution.
https://i.sstatic.net/1OplH.png
.button a {
padding: 8px 12px;
border-radius: 4px;
font-family: Helvetica, Arial, sans-serif;
font-size: 16px;
color: #ffffff;
text-decoration: none;
font-weight: bold;
display: inline-block;
float: none;
}
<tr>
<td class="plr-10" style="padding:0 60px;">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tbody style=""><tr>
<td style="padding-bottom: 10px;">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tbody><tr style="">
<td class="text-16 tx-grey" valign="top" width="10" style="font-family:'Segoe UI', Arial, sans-serif;font-size:16px;line-height:26px;text-align:left;min-width:auto !important;color:#929292;">
<strong style="font-weight: bold;">
<br>1.</strong>
</td>
<td class="img" width="10" style="font-size:0pt;line-height:0pt;text-align:left;"></td>
<td class="text-16" valign="top" style="color: rgb(37, 46, 93); font-family: "Segoe UI", Arial, sans-serif; font-size: 16px; line-height: 26px; text-align: left; min-width: auto !important;"><br>
Sample text Sample text Sample text Sample text Sample text Sample text Sample text Sample text Sample text Sample text Sample text Sample text .</td>
</tr>
</tbody></table>
</td>
</tr>
<tbody><tr>
<td class="button a">
<table width="40%" border="0" cellspacing="0" cellpadding="0">
<tbody><tr>
<td class="button" style="padding-bottom:25px; text-align: center">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tbody><tr>
<td class="button" width="240" style="font-family:'Segoe UI', Arial, sans-serif;font-size:12px;line-height:16px;min-width:auto !important;text-align:center;color:#ffffff;" bgcolor="#1b55f5" >
<a href="" target="_blank" class="link-grey" style="color:#b5b5b5;text-decoration:none;"><span class="link-grey" style="color: #ffffff; text-decoration: none;">Browse</span></a>
</td>
</tr>
</tbody></table>
</td>
</tr>
</tbody></table>
</td>
</tr>