Flexible, Robust, Responsive Theme

I have been using the Spacious theme since early in my WP site admin – for at least 5 years. I keep experimenting with other themes, particularly the WP/Automattic themes, but none of them provide the flexibility and responsiveness of the Spacious theme.
I love that pages can be configured with or without a left or right sidebar easily. The ratio of the sidebar to the main page can be configured with one line of CSS (easy to set and persists across updates, due to the thoughtful theme user interface design). Menus are similarly flexible and different page layouts can be combined at will. It is easy to configure the header, footer, sidebar, and main content area separately for the different types of page defined – these different page types permit an extremely flexible site layout, with different page-types sharing a common header and footer, but displaying content in totally different ways. No other theme that I have used provides so much flexibility.
The Spacious theme has proven to be robust, reliably responsive for mobile use, and ADA-compliant for accessibility needs. No matter what other themes I try, I always come back to Spacious!