商品图片悬停切换CSS3特效

<div class="demo">
	<div class="container">

		<div class="row">
			<div class="col-md-3 col-sm-6">
				<div class="product-grid">
					<div class="product-image">
						<a href="#" class="image">
							<img class="pic-1" src="images/img-1.jpg">
							<img class="pic-2" src="images/img-2.jpg">
						</a>
						<div class="product-button-group">
							<a href="#" class="add-to-wishlist">Add to wishlist</a>
							<a href="#" class="quick-view">Quick view</a>
						</div>
					</div>
					<div class="product-content">
						<h3 class="title"><a href="#">Women's Blouse Top</a></h3>
						<div class="price">$25.00</div>
						<a href="#" class="add-to-cart">Add to Cart</a>
					</div>
				</div>
			</div>
			<div class="col-md-3 col-sm-6">
				<div class="product-grid">
					<div class="product-image">
						<a href="#" class="image">
							<img class="pic-1" src="images/img-3.jpg">
							<img class="pic-2" src="images/img-4.jpg">
						</a>
						<span class="product-sale-label">Sale</span>
						<div class="product-button-group">
							<a href="#" class="add-to-wishlist">Add to wishlist</a>
							<a href="#" class="quick-view">Quick view</a>
						</div>
					</div>
					<div class="product-content">
						<h3 class="title"><a href="#">Men's Shirt</a></h3>
						<div class="price"><span>$35.00</span> $28.00</div>
						<a href="#" class="add-to-cart">Add to Cart</a>
					</div>
				</div>
			</div>
			<div class="col-md-3 col-sm-6">
				<div class="product-grid">
					<div class="product-image">
						<a href="#" class="image">
							<img class="pic-1" src="images/img-5.jpg">
							<img class="pic-2" src="images/img-6.jpg">
						</a>
						<span class="product-sale-label">Sale</span>
						<div class="product-button-group">
							<a href="#" class="add-to-wishlist">Add to wishlist</a>
							<a href="#" class="quick-view">Quick view</a>
						</div>
					</div>
					<div class="product-content">
						<h3 class="title"><a href="#">Women's Shirt</a></h3>
						<div class="price"><span>$27.00</span> $20.00</div>
						<a href="#" class="add-to-cart">Add to Cart</a>
					</div>
				</div>
			</div>
			<div class="col-md-3 col-sm-6">
				<div class="product-grid">
					<div class="product-image">
						<a href="#" class="image">
							<img class="pic-1" src="images/img-7.jpg">
							<img class="pic-2" src="images/img-8.jpg">
						</a>
						<span class="product-sale-label">Sale</span>
						<div class="product-button-group">
							<a href="#" class="add-to-wishlist">Add to wishlist</a>
							<a href="#" class="quick-view">Quick view</a>
						</div>
					</div>
					<div class="product-content">
						<h3 class="title"><a href="#">Men's Blazer</a></h3>
						<div class="price"><span>$33.00</span> $23.00</div>
						<a href="#" class="add-to-cart">Add to Cart</a>
					</div>
				</div>
			</div>
		</div>
	</div>
</div>