I'm using PureCSS and have a form that looks like:
<form class="pure-form">
<fieldset class="pure-group">
<input type="text" class="pure-input-1-2" placeholder="Username">
<textarea class="pure-input-1-2" placeholder="About me bio"></textarea>
</fieldset>
<fieldset class="pure-group">
<input type="text" class="pure-input-1-2" placeholder="Another Group">
<input type="text" class="pure-input-1-2" placeholder="More Stuff">
</fieldset>
<button type="submit" class="pure-button pure-input-1-2 pure-button-primary">Sign in</button>
</form>
Here's a JSfiddle.
Basically my issue is that with the two input group, the borders on focus show around the entire input, but with the one input and one textarea group, the borders on focus don't show on top of the textarea.