Responsive email width in Gmail

I have this email template:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <title>title</title>
    <style type="text/css">
    img { max-width: 600px;  -ms-interpolation-mode: bicubic;}
    .ReadMsgBody { width: 100%; }
    .ExternalClass {width:100%;}
    .backgroundTable {margin:0 auto; padding:0; width:100%;!important;}
    body {
      width: 100%;
      height: 100%;
      direction: rtl;
    }
    .force-full-width {
      width: 100% !important;
    }
    </style>
    <style type="text/css" media="only screen and (max-width: 599px)">
      @media only screen and (max-width: 599px) {
        table[class*="w320"] {
          width: 320px !important;
        }
      }
    </style>
  </head>
  <body dir="rtl" class="body" style="width:100vw; padding:0; margin:0; display:block; background:#ffffff; -webkit-text-size-adjust:none" bgcolor="#ffffff">
  <table align="center" cellpadding="0" cellspacing="0" width="100%">
    <tr>
      <td align="center" valign="top" style="background-color:#ffffff" width="100%">
      <center>
        <table cellspacing="0" cellpadding="0" width="600" class="w320">
          <tr>
            <td align="center" valign="top">
              <table class="force-full-width"  width="100%" cellspacing="0" cellpadding="20" bgcolor="#ef6900">
                <tr>
                  <td style="background-color:#ef6900; color:#ffffff; font-size: 14px; text-align: center;">
                    Some text
                  </td>
                </tr>
              </table>
              <!-- more tables -->
            </td>
          </tr>
        </table>
      </center>
      </td>
    </tr>
  </table>
  </body>
</html>

It does work on Gmail app in Android, but in desktop version email content overflows <u></u>. If I remove width:100vw; from body tag, desktop works fine but content overflows in mobile version. My Question is How can I make body width 100% in mobile and 600px on desktop? I tried max-width: 600px; in body style but it doesn't work. I also tried 100% instead of 100vw (because 100 vw is width of screen) and it does not work either.

Solution

I made a few changes, hope this is the outcome you were after. I have done the following:

removed width:100vwfrom the body
added the class body you are using on the body tag with the body CSS defined.
Changed the media query (removed space)

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><meta name="viewport" content="width=device-width, initial-scale=1" />
	<title>title</title>
	<style type="text/css">img { max-width: 600px;  -ms-interpolation-mode: bicubic;}
    .ReadMsgBody { width: 100%; }
    .ExternalClass {width:100%;}
    .backgroundTable {margin:0 auto; padding:0; width:100%;!important;}
    body, .body {
      width: 100%;
      height: 100%;
      direction: rtl;
    }
    .force-full-width {
      width: 100% !important;
    }
	</style>
	<style media="only screen and (max-width: 599px)" type="text/css">@media only screen and (max-width:599px) {
        table.w320 {
          width: 320px !important;
        }
      }
	</style>
</head>
<body bgcolor="#ffffff" class="body" dir="ltr" style="padding:0; margin:0; display:block; background:#ffffff; -webkit-text-size-adjust:none">
<table align="center" cellpadding="0" cellspacing="0" width="100%">
	<tbody>
		<tr>
			<td align="center" style="background-color:#ffffff" valign="top" width="100%">
			<center>
			<table cellpadding="0" cellspacing="0" class="w320" width="600">
				<tbody>
					<tr>
						<td align="center" valign="top">
						<table bgcolor="#ef6900" cellpadding="20" cellspacing="0" class="force-full-width" width="100%">
							<tbody>
								<tr>
									<td style="background-color:#ef6900; color:#ffffff; font-size: 14px; text-align: center;">Some text</td>
								</tr>
							</tbody>
						</table>
						<!-- more tables --></td>
					</tr>
				</tbody>
			</table>
			</center>
			</td>
		</tr>
	</tbody>
</table>
</body>
</html>

Above code tested in Outlook 2017 and Gmail app (v8.2.11) works properly now.

If you have any questions let me know.