Subscription Box Pure CSS Responsive

HTML

<div class='subscribe-box'>
<form action='http://feedburner.google.com/fb/a/mailverify?uri=Tapike' class='subscribe-box-form' method='post' onsubmit='window.open (&apos;http://feedburner.google.com/fb/a/mailverify?uri=Tapike&apos;, &apos;popupwindow&apos;, &apos;scrollbars=yes,width=550,height=520&apos;);return true' target='popupwindow'>
<input name='uri' type='hidden' value='Tapike'/><input name='loc' type='hidden' value='en_US'/><input autocomplete='off' class='subscribe-box-email-field' name='email' placeholder='Enter your email address '/><input class='subscribe-box-email-button' title='' type='submit' value='Subscribe Now !'/></form>
</div>
<br/><center>
<iframe src="//www.facebook.com/plugins/likebox.php?href=https://www.facebook.com/tapikecom&amp;width&amp;height=62&amp;colorscheme=light&amp;show_faces=false&amp;header=false&amp;stream=false&amp;show_border=false&amp;appId=159468740772399" scrolling="no" frameborder="0" style="border:none; overflow:hidden; height:62px;" allowTransparency="true"></iframe>
<!-- Tempatkan tag ini di head atau tepat sebelum tag body penutup. -->
<script src="https://apis.google.com/js/platform.js" async defer>
  {lang: 'id'}
</script>

<!-- Tempatkan tag ini di mana pun Anda ingin widget ditampilkan. -->
<div class="g-page" data-width="292" data-href="//plus.google.com/+Tapikecom" data-layout="landscape" data-rel="publisher"></div></center>

CSS

.subscribe-box{border-radius:4px;color:#fff; background:#eee; font-size:12px;line-height:20px;padding:1px 20px 10px;text-align:center;text-transform:none;font-weight:500}
form.subscribe-box-form{clear:both;display:block;margin:10px 0 0;width:auto;overflow:hidden}
.subscribe-box-email-field{outline:none;background:#fff url(http://1.bp.blogspot.com/-JMYdQsIa9WQ/UDZqxqqrTEI/AAAAAAAAFho/AocEv70U8K8/s1600/sprites.png) no-repeat 1px -27px;color:#444;margin:0 0 15px;padding:12px 40px;width:100%;border:none}
.subscribe-box-email-button{outline:none;background-color: #4d90fe;
  background-image: -webkit-linear-gradient(top,#4d90fe,#4787ed);color:#fff;cursor:pointer;font-weight:700;padding:10px;text-transform:none;width:100%;border:none;font-size:16px}