Atlantic Media's new business news website, Quartz, launched today. I wrote earlier about the five things journalists should know about this new project.

The first of those five things was Quartz's tablet-first focus, which we can now see in action.

Although the site is focused on reaching globetrotting business executives on their smartphones and tablets, you won't find it in your favorite app store.

As Peter Kafka notes in a preview piece today, Quartz is at that leading edge of digital publishing that uses responsive design and Web apps to get the job done from a single website:

Instead of asking readers to download an app to get its stuff on tablets or phones, Quartz will work on the mobile Web browsers those machines already have. And it will publish a single Web site, which will configure itself depending on the kind of device and screen size each reader uses.

There are some clear benefits to this approach.

1. All Quartz content is accessible through any browser, not just on certain devices. That's good for owners of Android, Windows, or BlackBerry tablets. It's even good for iPad owners -- major news organizations like NPR and Politico find that many iPad users read their websites, even though they have apps available.

2. Each Quartz article can be linked to and shared using a single URL. No "" redirects and no app redirects. That's also helpful for mobile users, who discover a lot of content through Facebook or Twitter links and want to be able to open them easily on their devices.

3. Quartz has an independent platform that it controls entirely. Changes can be deployed immediately without app store review. Any eventual subscription options will not be subject to the app store's 30 percent fee.

Overall, Quartz is launching with quite a nice user interface that achieves the elegant style it was surely aiming to bring to an upper-class audience.

Quartz's no-ads strategy preserves uniformity and simplicity in its design. (The site will lean on sponsored content and events revenue instead of traditional display ads.)

Your typical business news site is organized into generic categories (E.g., World | US | New York | Business | Tech | Markets, etc.) and thick lists of subcategories. But Quartz uses a single thin, horizontally scrollable navigation bar that lists the site's current "obsessions" -- the phenomena its reporters are tracking closely. Energy shocks, China slowdown, Euro crunch and Low interest rates are some current ones.

There's room for improvement, though. For my taste, the iPad/desktop version devotes too much space to the header and the sidebar navigation, making the articles feel squeezed.

On an iPad screen in landscape orientation, the article-viewing pane occupies only 60 percent of the screen. The header (15 percent) and left-hand sidebar (25 percent) eat up quite a bit of space. It would be nice to immerse into an article when reading it and collapse some of those other panes.

The smartphone version of the site does this nicely. The main menu is hidden with a button in the header to show it on demand. Most of the screen is saved for the headline list or article.

For more examples of websites-as-tablet apps, see the Boston Globe's responsive site launched in 2011 and the recent tablet-focused beta redesign of In the very near future, expect to see The Atlantic Wire and PBS websites relaunch as mobile-optimized Web apps as well.