I've got these footer buttons placed next to each other that i want to stack on top of each other when switched to mobile. It works well everywhere except for Android Gmail App IMAP, Android 5.1 and Android 6.0.
Please help.

Here is what it looks like: https://litmus.com/checklist/public/1c20bce

And here is the code:


    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html style="margin:0;padding:0">

    <head>
        <meta http-equiv="content-type" content="text/html; charset=UTF-8">
        <meta name="viewport" content="width=device-width,initial-scale=1">
        <title></title>
        <style type="text/css">
            @media only screen and (max-width: 740px) {
                .responsive {
                    width: 100%;
                    max-width: 100% !important;
                    min-width: 100% !important;
                    height: auto !important;
                    max-height: none !important;
                    margin: 0 !important;
                }
            }

        </style>
    </head>

    <body style="margin:0;padding:0;background:#1a1c52">
        <table align="center" bgcolor="#1a1c52" border="0" cellpadding="0" cellspacing="0" width="100%">
            <tr style="margin:0 auto">
                <td align="center" style="-webkit-text-size-adjust:100%;font-family:Arial,Arial CE,Helvetica,sans-serif;padding:10px;font-size:16px" width="740">
                    <!--[if (gte mso 9)|(IE)]>
                    <table width="720" align="center">
                    <tr>
                    <td>
                    <![endif]-->

                    <!--    LAYOUT  -->
                    <table align="center" border="0" border-spacing="0" cellpadding="0" cellspacing="0" style="font-family:Arial,sans-serif; max-width:720px; min-width: 320px;" width="100%">
                        <tr>
                            <td align="center" style="font-size:0;">
                                <!--[if (gte mso 9)|(IE)]>
                                <table width="100%" cellpadding="0" cellspacing="0" border="0">
                                <tr>
                                <td width="165" valign="top">
                                <![endif]-->
                                <div class="responsive" style="width: 100%; max-width: 165px; display: inline-block; vertical-align: top;">
                                    <table width="100%" align="center" cellspacing="0" cellpadding="0" border="0">
                                        <tr>
                                            <td width="165" height="40" bgcolor="#3b5998" style="color:#ffffff; -webkit-border-radius:3px; border-radius:3px; min-width:165px; width:100%;" align="center" valign="middle">
                                                <a href="www" target="_blank" style="font-size:15px; font-family:Arial,'Open Sans',Helvetica,sans-serif; font-weight:normal; color:#ffffff; text-decoration:none; text-decoration:none!important; display:inline-block; line-height:40px;">
                                                    <img src="https://u.mailkit.eu/user.fcgi/action,img_local/dc,8497/df,116044" style="display:inline-block; border: none; outline: none; text-decoration: none; text-decoration:none!important; vertical-align:middle;" alt="" width="8" height="16">&nbsp; Facebook
                                                </a>
                                            </td>
                                        </tr>
                                    </table>
                                </div>
                                <!--[if (gte mso 9)|(IE)]></td><td width="20" valign="top"><![endif]-->
                                <div class="responsive" style="width: 100%; max-width: 20px; display: inline-block; vertical-align: top;">
                                    <table width="100%" align="center" cellspacing="0" cellpadding="0" border="0">
                                        <tr>
                                            <td height="10" width="20" style="font-size:10px; line-height:10px; width:100%;">&nbsp;</td>
                                        </tr>
                                    </table>
                                </div>
                                <!--[if (gte mso 9)|(IE)]></td><td width="165" valign="top"><![endif]-->
                                <div class="responsive" style="width: 100%; max-width: 165px; display: inline-block; vertical-align: top;">
                                    <table width="100%" align="center" cellspacing="0" cellpadding="0" border="0">
                                        <tr>
                                            <td width="165" height="40" bgcolor="#55acee" style="color:#ffffff; -webkit-border-radius:3px; border-radius:3px; min-width:165px; width:100%;" align="center" valign="middle">
                                                <a href="www" target="_blank" style="font-size:15px; font-family:Arial,'Open Sans',Helvetica,sans-serif; font-weight:normal; color:#ffffff; text-decoration:none; text-decoration:none!important; display:inline-block; line-height:40px;">
                                                    <img src="https://u.mailkit.eu/user.fcgi/action,img_local/dc,8497/df,116046" style="display:inline-block; border: none; outline: none; text-decoration: none; text-decoration:none!important; vertical-align:middle;" alt="" width="19" height="13">&nbsp; Twitter
                                                </a>
                                            </td>
                                        </tr>
                                    </table>
                                </div>
                                <!--[if (gte mso 9)|(IE)]></td><td width="20" valign="top"><![endif]-->
                                <div class="responsive" style="width: 100%; max-width: 20px; display: inline-block; vertical-align: top;">
                                    <table width="100%" align="center" cellspacing="0" cellpadding="0" border="0">
                                        <tr>
                                            <td height="10" width="20" style="font-size:10px; line-height:10px; width:100%;">&nbsp;</td>
                                        </tr>
                                    </table>
                                </div>
                                <!--[if (gte mso 9)|(IE)]></td><td width="165" valign="top"><![endif]-->
                                <div class="responsive" style="width: 100%; max-width: 165px; display: inline-block; vertical-align: top;">
                                    <table width="100%" align="center" cellspacing="0" cellpadding="0" border="0">
                                        <tr>
                                            <td width="165" height="40" bgcolor="#cd201f" style="color:#ffffff; -webkit-border-radius:3px; border-radius:3px; min-width:165px; width:100%;" align="center" valign="middle">
                                                <a href="www" target="_blank" style="font-size:15px; font-family:Arial,'Open Sans',Helvetica,sans-serif; font-weight:normal; color:#ffffff; text-decoration:none; text-decoration:none!important; display:inline-block; line-height:40px;">
                                                    <img src="https://u.mailkit.eu/user.fcgi/action,img_local/dc,8497/df,116047" style="display:inline-block; border: none; outline: none; text-decoration: none; text-decoration:none!important; vertical-align:middle;" alt="" width="15" height="18">&nbsp; Youtube
                                                </a>
                                            </td>
                                        </tr>
                                    </table>
                                </div>
                                <!--[if (gte mso 9)|(IE)]></td><td width="20" valign="top"><![endif]-->
                                <div class="responsive" style="width: 100%; max-width: 20px; display: inline-block; vertical-align: top;">
                                    <table width="100%" align="center" cellspacing="0" cellpadding="0" border="0">
                                        <tr>
                                            <td height="10" width="20" style="font-size:10px; line-height:10px; width:100%;">&nbsp;</td>
                                        </tr>
                                    </table>
                                </div>
                                <!--[if (gte mso 9)|(IE)]></td><td width="165" valign="top"><![endif]-->
                                <div class="responsive" style="width: 100%; max-width: 165px; display: inline-block; vertical-align: top;">
                                    <table width="100%" align="center" cellspacing="0" cellpadding="0" border="0">
                                        <tr>
                                            <td width="165" height="40" bgcolor="#3f729b" style="color:#ffffff; -webkit-border-radius:3px; border-radius:3px; min-width:165px; width:100%;" align="center" valign="middle">
                                                <a href="www" target="_blank" style="font-size:15px; font-family:Arial,'Open Sans',Helvetica,sans-serif; font-weight:normal; color:#ffffff; text-decoration:none; text-decoration:none!important; display:inline-block; line-height:40px;">
                                                    <img src="https://u.mailkit.eu/user.fcgi/action,img_local/dc,8497/df,116045" style="display:inline-block; border: none; outline: none; text-decoration: none; text-decoration:none!important; vertical-align:middle;" alt="" width="17" height="17">&nbsp; Instagram
                                                </a>
                                            </td>
                                        </tr>
                                    </table>
                                </div>
                                <!--[if (gte mso 9)|(IE)]>
                                </td>
                                </tr>
                                </table>
                                <![endif]-->
                            </td>
                        </tr>
                    </table>
                    <!--[if (gte mso 9)|(IE)]>
                    </td>
                    </tr>
                    </table>
                    <![endif]-->
                </td>
            </tr>
        </table>
    </body>