Unwanted gaps appear on the template (Django) - html

Question

I give the products to the page with the loop in the template, but there is a problem. There is a gap on the page and I can't find the reason. Most likely because of HTML codes. I will be glad if you help.
This gap in the middle
products.html
<!-- STORE -->
<div id="store">
<!-- row -->
<div class="row">
<!-- Product Single -->
{% for product in products %}
{% if product.available %}
<div class="col-md-4 col-sm-6 col-xs-6">
<div class="product product-single">
<div class="product-thumb">
<div class="product-label">
<span>New</span>
{% if product.sale %}
<span class="sale">-{{product.sale}}%</span>
{% endif %}
</div>
<button class="main-btn quick-view"><i class="fa fa-search-plus"></i> Göz At</button>
<img src="{{product.main_image.url}}" alt="">
</div>
<div class="product-body">
{% if product.sale %}
<h3 class="product-price">{{product.discount}} AZN <del class="product-old-price">{{product.price}} AZN</del></h3>
{% else %}
<h3 class="product-price">{{product.price}} AZN</h3>
{% endif %}
<div class="product-rating">
<i class="fa fa-star"></i>
<i class="fa fa-star"></i>
<i class="fa fa-star"></i>
<i class="fa fa-star"></i>
<i class="fa fa-star-o empty"></i>
</div>
<h2 class="product-name">{{product.name}}</h2>
<div class="product-btns">
<button class="main-btn icon-btn"><i class="fa fa-heart"></i></button>
<button class="main-btn icon-btn"><i class="fa fa-exchange"></i></button>
<button class="primary-btn add-to-cart"><i class="fa fa-shopping-cart"></i> Səbətə At</button>
</div>
</div>
</div>
</div>
{% endif %}
{% endfor %}
<!-- /Product Single -->
</div>
<!-- /row -->
</div>
<!-- /STORE -->