<li><input type="text" name="email" placeholder="Email" value="<?php echo $_POST['email'] ?>"></li>
<li>
<input type="text" name="phone" placeholder="Телефон" value="<?php echo $_POST['phone'] ?>">
</li>
<li><input type="text" name="fio" placeholder="Ф.И.О." value="<?php echo $_POST['fio'] ?>"></li>
<li><textarea class="address-area" placeholder="Адрес доставки" name="address"><?php echo $_POST['address'] ?></textarea>
</li>
<li><textarea class="address-area" placeholder="Комментарий к заказу" name="info"><?php echo $_POST['info'] ?></textarea></li>