<form method="post">
<div class="form-group" style="margin-bottom:5px;">
<input type="text" class="form-control" placeholder="Логин:" name="login" required><br>
<input type="password" class="form-control" placeholder="Пароль:" name="password" required><br>
<button type="submit" class="btn btn-primary" name="submit" style="float:right;">Войти</button>
</div>
</form>
href="category.php?id=<?=$category_id?>&page=
href="?page=