Some CSS ID/Class in Avenue template Squarespace.

The code is checked on Avenue demo template at Squarespace.com/templates

Header

• site title: .site-title .logo a
• tagline: .logo-subtitle
• logo: .logo-image .logo img
• navigation: #topNav nav
• navigation items: #topNav nav li a
• mobile menu text: #mobileMenuLink a
• mobile navigation: #mobileNav
• mobile navigation items: #mobileNav nav ul li a
• header: header#header

Footer

• footer: footer#footer
• footer links: footer#footer a

Blog List

• blog list page: .collection-type-blog.view-list
• blog title: h1.entry-title a
• blog date: time.published
• share text: .ss-social-button
• like count: span.like-count
• like icon: .sqs-simple-like .like-icon
• blog post item: .collection-type-blog.view-list article
• sidebar: aside#sidebar
• sidebar blog title: aside#sidebar .summary-title-link
• sidebar blog date: aside#sidebar time.summary-metadata-item.summary-metadata-item–date

Blog Detail

• blog detail page: .collection-type-blog.view-item
• blog title: h1.entry-title a
• blog date: time.published
• share text: .ss-social-button
• like count: span.like-count
• like icon: .sqs-simple-like .like-icon
• pagination: .collection-type-blog .pagination
• pagination text: .collection-type-blog .pagination a
• pagination next: .next-item
• pagination pre: .prev-item
• sidebar: aside#sidebar
• sidebar blog title: aside#sidebar .summary-title-link
• sidebar blog date: aside#sidebar time.summary-metadata-item.summary-metadata-item–date

Work List Page (Index)

• list page: .collection-type-index.view-list
• item: #projectThumbs .project
• title: #projectThumbs .project .project-title
• image: #projectThumbs .project img

Work Detail Page (Index item)

• detail page: .collection-type-index.view-list.index-page-open
• image: #projectPages .project.active-project .image-list .image>img
• titlte: #projectPages h2.project-title
• description: .project-description
• back to work: .page-open #projectPages .project-controls #projectNav+a
• prev/next: .page-open #projectPages .project-controls #projectNav
• related project: .page-open #projectThumbs .project

Homepage

• homepage: .homepage

Shop Page

• shop page: .collection-type-products.view-list
• category filter: .category-nav
• category filter item: .category-nav li a
• product: #productList .product
• product name: #productList .product .product-title
• product image: #productList .product .product-image img
• price: #productList .product .product-price

Product Detail Page

• product detail page: .collection-type-products.view-item
• back to products: div#productNav
• product name: #productDetails .product-title
• price: #productDetails .product-price
• description: .product-excerpt
• add to cart text: .sqs-add-to-cart-button-inner
• add to cart button: .sqs-add-to-cart-button
• share: .product-social-sharing .product-sharing
• gallery image: #productGallery
• additional descripiton: .product-description

Cart Page

• cart page: body#cart
• cart title: .cart-title
• item label: span.CartTable-itemLabel-3zzV1 span
• qty. label: span.CartTable-itemLabel-3zzV1 span
• price label: span.CartTable-itemLabel-3zzV1 span
• x icon: .CartTableRow-itemRemove-6Q3nP button span
• product name: .CartTableRow-itemTitle-1MDgZ a
• product image: .CartTableRow-imageBg-97RUm
• qty input: input.QuantityInput-stopped-2BFKB
• price: .CartTableRow-itemPrice-26eXS
• subtotal label: .CartTable-subtotalLabel-3qWE9
• subtotal price: .CartTable-subtotalPrice-2JFeD
• checkout button: body .checkout button.CheckoutButton-checkoutButton-3yWY2
• checkout text: body .checkout button.CheckoutButton-checkoutButton-3yWY2 span