Title: Shopify Product Quick View
Description: A lightweight product quick view modal that displays product details without leaving the current page.
Code:
<!-- Product Quick View Modal HTML -->
<div id="quick-view-modal" class="quick-view-modal">
  <div class="quick-view-container">
    <div class="quick-view-close">&times;</div>
    <div class="quick-view-content">
      <div class="quick-view-loader">
        <div class="spinner"></div>
      </div>
      <div class="quick-view-product-content" id="quick-view-product-content"></div>
    </div>
  </div>
</div>

<!-- Product Quick View Modal Content Template -->
<template id="quick-view-template">
  <div class="quick-view-product">
    <div class="quick-view-product-gallery">
      <div class="quick-view-product-image">
        <img src="" alt="" class="quick-view-featured-image">
      </div>
      <div class="quick-view-thumbnails"></div>
    </div>
    <div class="quick-view-product-details">
      <h2 class="quick-view-product-title"></h2>
      <div class="quick-view-product-price"></div>
      <div class="quick-view-product-description"></div>
      
      <form action="/cart/add" method="post" class="quick-view-product-form">
        <input type="hidden" name="id" value="" class="quick-view-variant-id">
        
        <div class="quick-view-product-options"></div>
        
        <div class="quick-view-quantity-wrapper">
          <label for="quick-view-quantity">Quantity</label>
          <div class="quick-view-quantity-input">
            <button type="button" class="quick-view-quantity-decrease">-</button>
            <input type="number" id="quick-view-quantity" name="quantity" value="1" min="1">
            <button type="button" class="quick-view-quantity-increase">+</button>
          </div>
        </div>
        
        <div class="quick-view-submit">
          <button type="submit" class="quick-view-add-to-cart">Add to Cart</button>
        </div>
        
        <div class="quick-view-view-details">
          <a href="" class="quick-view-product-link">View Full Details</a>
        </div>
      </form>
    </div>
  </div>
</template>

<!-- Product Quick View CSS -->
<style>
.quick-view-modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  overflow-y: auto;
}

.quick-view-container {
  position: relative;
  width: 90%;
  max-width: 1000px;
  margin: 50px auto;
  background-color: #fff;
  border-radius: 4px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.5);
}

.quick-view-close {
  position: absolute;
  top: 10px;
  right: 15px;
  font-size: 28px;
  font-weight: 700;
  color: #333;
  cursor: pointer;
  z-index: 10;
}

.quick-view-content {
  padding: 20px;
  position: relative;
  min-height: 200px;
}

.quick-view-loader {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(255, 255, 255, 0.9);
  z-index: 5;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid #f3f3f3;
  border-top: 4px solid #333;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.quick-view-product {
  display: flex;
  flex-wrap: wrap;
}

.quick-view-product-gallery {
  width: 50%;
  padding-right: 20px;
}

.quick-view-product-details {
  width: 50%;
}

.quick-view-product-image {
  margin-bottom: 15px;
}

.quick-view-featured-image {
  width: 100%;
  height: auto;
}

.quick-view-thumbnails {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.quick-view-thumbnail {
  width: 60px;
  height: 60px;
  border: 1px solid #ddd;
  cursor: pointer;
  overflow: hidden;
}

.quick-view-thumbnail.active {
  border-color: #000;
}

.quick-view-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.quick-view-product-title {
  margin-top: 0;
  margin-bottom: 10px;
  font-size: 24px;
}

.quick-view-product-price {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 15px;
}

.quick-view-product-description {
  margin-bottom: 20px;
  font-size: 14px;
  line-height: 1.6;
}

.quick-view-product-options {
  margin-bottom: 20px;
}

.quick-view-option-selector {
  margin-bottom: 15px;
}

.quick-view-option-selector label {
  display: block;
  margin-bottom: 5px;
  font-weight: 500;
}

.quick-view-option-selector select {
  width: 100%;
  padding: 8px;
  border: 1px solid #ddd;
  border-radius: 4px;
}

.quick-view-quantity-wrapper {
  margin-bottom: 20px;
}

.quick-view-quantity-wrapper label {
  display: block;
  margin-bottom: 5px;
  font-weight: 500;
}

.quick-view-quantity-input {
  display: flex;
  align-items: center;
  width: fit-content;
  border: 1px solid #ddd;
  border-radius: 4px;
  overflow: hidden;
}

.quick-view-quantity-input button {
  width: 30px;
  height: 38px;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 16px;
}

.quick-view-quantity-input input {
  width: 50px;
  height: 38px;
  border: none;
  border-left: 1px solid #ddd;
  border-right: 1px solid #ddd;
  text-align: center;
  -moz-appearance: textfield;
}

.quick-view-quantity-input input::-webkit-outer-spin-button,
.quick-view-quantity-input input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.quick-view-add-to-cart {
  width: 100%;
  padding: 12px;
  background-color: #000;
  color: #fff;
  border: none;
  border-radius: 4px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.3s;
}

.quick-view-add-to-cart:hover {
  background-color: #333;
}

.quick-view-add-to-cart.disabled {
  background-color: #ccc;
  cursor: not-allowed;
}

.quick-view-view-details {
  margin-top: 15px;
  text-align: center;
}

.quick-view-product-link {
  color: #333;
  text-decoration: underline;
}

@media (max-width: 768px) {
  .quick-view-product-gallery,
  .quick-view-product-details {
    width: 100%;
    padding-right: 0;
  }
  
  .quick-view-product-gallery {
    margin-bottom: 20px;
  }
}
</style>

<!-- Quick View JS -->
<script>
document.addEventListener('DOMContentLoaded', function() {
  const quickViewButtons = document.querySelectorAll('[data-quick-view]');
  const quickViewModal = document.getElementById('quick-view-modal');
  const quickViewClose = document.querySelector('.quick-view-close');
  const quickViewContent = document.getElementById('quick-view-product-content');
  const quickViewLoader = document.querySelector('.quick-view-loader');
  const quickViewTemplate = document.getElementById('quick-view-template');
  
  // Add quick view buttons to product cards
  quickViewButtons.forEach(button => {
    button.addEventListener('click', function(e) {
      e.preventDefault();
      const productHandle = this.getAttribute('data-product-handle');
      openQuickView(productHandle);
    });
  });
  
  // Close modal when clicking the X
  if (quickViewClose) {
    quickViewClose.addEventListener('click', closeQuickView);
  }
  
  // Close modal when clicking outside of content
  quickViewModal.addEventListener('click', function(e) {
    if (e.target === quickViewModal) {
      closeQuickView();
    }
  });
  
  // Close modal with ESC key
  document.addEventListener('keydown', function(e) {
    if (e.key === 'Escape' && quickViewModal.style.display === 'block') {
      closeQuickView();
    }
  });
  
  // Open quick view modal and load product
  function openQuickView(productHandle) {
    // Show modal
    quickViewModal.style.display = 'block';
    document.body.style.overflow = 'hidden'; // Prevent scrolling
    
    // Show loader
    quickViewLoader.style.display = 'flex';
    quickViewContent.innerHTML = '';
    
    // Fetch product data
    fetch(`/products/${productHandle}?view=quick-view`)
      .then(response => response.text())
      .then(html => {
        // If the response is HTML (using a custom template)
        loadProductHTML(html);
      })
      .catch(error => {
        // If the custom template doesn't exist, fetch JSON data
        fetch(`/products/${productHandle}.js`)
          .then(response => response.json())
          .then(product => {
            loadProductJSON(product);
          })
          .catch(error => {
            console.error('Error loading product:', error);
            quickViewContent.innerHTML = '<p>Error loading product. Please try again.</p>';
            quickViewLoader.style.display = 'none';
          });
      });
  }
  
  // Load product from HTML template
  function loadProductHTML(html) {
    quickViewContent.innerHTML = html;
    initializeQuickView();
    quickViewLoader.style.display = 'none';
  }
  
  // Load product from JSON data
  function loadProductJSON(product) {
    // Clone the template
    const content = quickViewTemplate.content.cloneNode(true);
    
    // Set product data
    content.querySelector('.quick-view-product-title').textContent = product.title;
    content.querySelector('.quick-view-product-price').innerHTML = formatMoney(product.price);
    content.querySelector('.quick-view-product-description').innerHTML = product.description;
    content.querySelector('.quick-view-product-link').href = `/products/${product.handle}`;
    
    // Set featured image
    if (product.featured_image) {
      const featuredImage = content.querySelector('.quick-view-featured-image');
      featuredImage.src = product.featured_image;
      featuredImage.alt = product.title;
    }
    
    // Add thumbnail images
    const thumbnailsContainer = content.querySelector('.quick-view-thumbnails');
    product.images.forEach((image, index) => {
      const thumbnail = document.createElement('div');
      thumbnail.className = 'quick-view-thumbnail';
      if (index === 0) thumbnail.classList.add('active');
      
      const img = document.createElement('img');
      img.src = image;
      img.alt = `${product.title} - Image ${index + 1}`;
      
      thumbnail.appendChild(img);
      thumbnail.addEventListener('click', function() {
        // Set new featured image
        content.querySelector('.quick-view-featured-image').src = image;
        // Update active thumbnail
        content.querySelectorAll('.quick-view-thumbnail').forEach(thumb => {
          thumb.classList.remove('active');
        });
        this.classList.add('active');
      });
      
      thumbnailsContainer.appendChild(thumbnail);
    });
    
    // Add variant options
    if (product.options_with_values && product.options_with_values.length > 0) {
      const optionsContainer = content.querySelector('.quick-view-product-options');
      
      product.options_with_values.forEach(option => {
        const optionSelector = document.createElement('div');
        optionSelector.className = 'quick-view-option-selector';
        
        const label = document.createElement('label');
        label.textContent = option.name;
        label.htmlFor = `quick-view-option-${option.name.toLowerCase().replace(/\s+/g, '-')}`;
        
        const select = document.createElement('select');
        select.id = `quick-view-option-${option.name.toLowerCase().replace(/\s+/g, '-')}`;
        select.className = 'quick-view-option-select';
        select.dataset.option = option.position;
        
        option.values.forEach(value => {
          const optionEl = document.createElement('option');
          optionEl.value = value;
          optionEl.textContent = value;
          select.appendChild(optionEl);
        });
        
        optionSelector.appendChild(label);
        optionSelector.appendChild(select);
        optionsContainer.appendChild(optionSelector);
      });
      
      // Add event listeners to update variant ID
      content.querySelectorAll('.quick-view-option-select').forEach(select => {
        select.addEventListener('change', function() {
          updateVariantSelection(content, product);
        });
      });
      
      // Initialize variant selection
      updateVariantSelection(content, product);
    } else {
      // Single variant - set the variant ID directly
      content.querySelector('.quick-view-variant-id').value = product.variants[0].id;
    }
    
    // Add quantity buttons functionality
    const quantityInput = content.querySelector('#quick-view-quantity');
    content.querySelector('.quick-view-quantity-decrease').addEventListener('click', function() {
      if (quantityInput.value > 1) {
        quantityInput.value = parseInt(quantityInput.value) - 1;
      }
    });
    
    content.querySelector('.quick-view-quantity-increase').addEventListener('click', function() {
      quantityInput.value = parseInt(quantityInput.value) + 1;
    });
    
    // Add to cart functionality
    const addToCartForm = content.querySelector('.quick-view-product-form');
    addToCartForm.addEventListener('submit', function(e) {
      e.preventDefault();
      
      const addToCartButton = this.querySelector('.quick-view-add-to-cart');
      const originalText = addToCartButton.textContent;
      
      // Disable button during submission
      addToCartButton.disabled = true;
      addToCartButton.textContent = 'Adding...';
      
      // Prepare form data
      const formData = new FormData(this);
      
      // Add to cart via AJAX
      fetch('/cart/add.js', {
        method: 'POST',
        body: formData
      })
        .then(response => response.json())
        .then(data => {
          addToCartButton.textContent = 'Added!';
          
          // Update cart count or show mini cart
          updateCartCount();
          
          // Close quick view after delay
          setTimeout(() => {
            closeQuickView();
            addToCartButton.disabled = false;
            addToCartButton.textContent = originalText;
          }, 1500);
        })
        .catch(error => {
          console.error('Error adding to cart:', error);
          addToCartButton.textContent = 'Error - Try Again';
          setTimeout(() => {
            addToCartButton.disabled = false;
            addToCartButton.textContent = originalText;
          }, 1500);
        });
    });
    
    // Add content to modal
    quickViewContent.appendChild(content);
    quickViewLoader.style.display = 'none';
  }
  
  // Update variant selection based on option selects
  function updateVariantSelection(content, product) {
    // Get selected options
    const selectedOptions = [];
    content.querySelectorAll('.quick-view-option-select').forEach(select => {
      selectedOptions[parseInt(select.dataset.option) - 1] = select.value;
    });
    
    // Find matching variant
    let matchingVariant = null;
    for (const variant of product.variants) {
      if (variant.options.every((option, index) => option === selectedOptions[index])) {
        matchingVariant = variant;
        break;
      }
    }
    
    if (matchingVariant) {
      // Update variant ID and price
      content.querySelector('.quick-view-variant-id').value = matchingVariant.id;
      
      if (matchingVariant.available) {
        content.querySelector('.quick-view-add-to-cart').disabled = false;
        content.querySelector('.quick-view-add-to-cart').textContent = 'Add to Cart';
        content.querySelector('.quick-view-add-to-cart').classList.remove('disabled');
      } else {
        content.querySelector('.quick-view-add-to-cart').disabled = true;
        content.querySelector('.quick-view-add-to-cart').textContent = 'Sold Out';
        content.querySelector('.quick-view-add-to-cart').classList.add('disabled');
      }
      
      // Update price if different
      if (matchingVariant.price !== product.price) {
        content.querySelector('.quick-view-product-price').innerHTML = formatMoney(matchingVariant.price);
      }
    }
  }
  
  // Initialize quick view functionality after HTML is loaded
  function initializeQuickView() {
    // Add functionality to quantity buttons
    const quantityInput = quickViewContent.querySelector('#quick-view-quantity');
    if (quantityInput) {
      quickViewContent.querySelector('.quick-view-quantity-decrease')?.addEventListener('click', function() {
        if (quantityInput.value > 1) {
          quantityInput.value = parseInt(quantityInput.value) - 1;
        }
      });
      
      quickViewContent.querySelector('.quick-view-quantity-increase')?.addEventListener('click', function() {
        quantityInput.value = parseInt(quantityInput.value) + 1;
      });
    }
    
    // Add functionality to thumbnails
    const thumbnails = quickViewContent.querySelectorAll('.quick-view-thumbnail');
    thumbnails.forEach(thumbnail => {
      thumbnail.addEventListener('click', function() {
        const newSrc = this.querySelector('img').src;
        quickViewContent.querySelector('.quick-view-featured-image').src = newSrc;
        
        thumbnails.forEach(t => t.classList.remove('active'));
        this.classList.add('active');
      });
    });
    
    // Add to cart functionality
    const addToCartForm = quickViewContent.querySelector('.quick-view-product-form');
    if (addToCartForm) {
      addToCartForm.addEventListener('submit', function(e) {
        e.preventDefault();
        
        const addToCartButton = this.querySelector('.quick-view-add-to-cart');
        const originalText = addToCartButton.textContent;
        
        // Disable button during submission
        addToCartButton.disabled = true;
        addToCartButton.textContent = 'Adding...';
        
        // Add to cart via AJAX
        fetch('/cart/add.js', {
          method: 'POST',
          body: new FormData(this),
          headers: {
            'X-Requested-With': 'XMLHttpRequest'
          }
        })
          .then(response => response.json())
          .then(data => {
            addToCartButton.textContent = 'Added!';
            
            // Update cart count or show mini cart
            updateCartCount();
            
            setTimeout(() => {
              closeQuickView();
              addToCartButton.disabled = false;
              addToCartButton.textContent = originalText;
            }, 1500);
          })
          .catch(error => {
            console.error('Error adding to cart:', error);
            addToCartButton.textContent = 'Error - Try Again';
            setTimeout(() => {
              addToCartButton.disabled = false;
              addToCartButton.textContent = originalText;
            }, 1500);
          });
      });
    }
    
    // Add variant changing functionality
    const variantSelectors = quickViewContent.querySelectorAll('.quick-view-option-select');
    if (variantSelectors.length) {
      variantSelectors.forEach(selector => {
        selector.addEventListener('change', function() {
          // Update product variant
          // This functionality would depend on your specific Shopify theme
        });
      });
    }
  }
  
  // Close quick view modal
  function closeQuickView() {
    quickViewModal.style.display = 'none';
    document.body.style.overflow = '';
    quickViewContent.innerHTML = '';
  }
  
  // Format money value
  function formatMoney(cents) {
    const currency = window.Shopify?.currency?.active || 'USD';
    const formatter = new Intl.NumberFormat('en-US', {
      style: 'currency',
      currency,
      minimumFractionDigits: 2
    });
    
    return formatter.format(cents / 100);
  }
  
  // Update cart count (depends on theme structure)
  function updateCartCount() {
    fetch('/cart.js')
      .then(response => response.json())
      .then(cart => {
        const cartCountElements = document.querySelectorAll('.cart-count');
        cartCountElements.forEach(element => {
          element.textContent = cart.item_count;
        });
      })
      .catch(error => {
        console.error('Error updating cart count:', error);
      });
  }
});
</script>

<!-- Add these quick view buttons to your collection template or product card snippet -->
<!--
<button class="quick-view-button" data-quick-view data-product-handle="{{ product.handle }}">
  Quick View
</button>
-->

<!-- Add a special quick-view template to your theme -->
<!--
Create a template at templates/product.quick-view.liquid with the product content
you want to display in the quick view modal
-->