See the details here
<form action="<?php echo JRoute::_('index.php?option=com_users&task=user.login'); ?>" method="post">
<fieldset>
<?php foreach ($this->form->getFieldset('credentials') as $field): ?>
<?php if (!$field->hidden): ?>
<div class="login-fields"><?php echo $field->label; ?>
<?php echo $field->input; ?></div>
<?php endif; ?>
<?php endforeach; ?>
<button type="submit" class="button"><?php echo JText::_('JLOGIN'); ?></button>
<input type="hidden" name="return" value="<?php echo base64_encode($this->params->get('login_redirect_url', $this->form->getValue('return'))); ?>" />
<?php echo JHtml::_('form.token'); ?>
</fieldset>
</form>
<form action="<?php echo JRoute::_('index.php?option=com_users&task=user.login'); ?>" method="post">
<fieldset style="border: 1px solid #CCCCCC; border-radius: 5px 5px 5px 5px; margin: 50px auto 0 auto; padding-bottom: 50px; padding-left: 50px; padding-top: 50px; width: 350px;">
<p style="margin-bottom: 5px;">type a message here if you would like.</p>
<?php foreach ($this->form->getFieldset('credentials') as $field): ?>
<?php if (!$field->hidden): ?>
<div class="login-fields"><?php echo $field->label; ?>
<?php echo $field->input; ?></div>
<?php endif; ?>
<?php endforeach; ?>
<button type="submit" class="button" style="float: right; margin: 10px 87px 0 0;"><?php echo JText::_('JLOGIN'); ?></button>
<input type="hidden" name="return" value="<?php echo base64_encode($this->params->get('login_redirect_url', $this->form->getValue('return'))); ?>" />
<?php echo JHtml::_('form.token'); ?>
</fieldset>
</form>