If you build a web site today you need to think about the experience on mobiles, tablets and desktops with different screen sizes. This is not very easy. In this article I have applications (SPAs) in mind rather than sites/pages.

If you are a real, ambitious, skilled designer with a significant budget, there is nothing stopping you from doing it right. Responsive design is dead, because most often you have no choice, so it is just design.

However, you may not have that budget, skill, time and ambition, but you still need to think about vastly different screen sizes. Or perhaps you just need to build a simple native-app-like website.

Two separate implementations

In many cases I would argue that it makes sense to simply make a separate site for mobile and desktop. There are many arguments but I will give one: use cases are often very different. A desktop app is often opened, kept open for a long time, and much data may be presented and analysed on screen, in memory. A mobile app is often opened shortly, to accomplish a single task, and then closed. This means that you probably want to manage state, data and workflow very differently as well.

Bootstrap (or similar)

There are frameworks (like Bootstrap) and technologies like Flexbox to allow you to build a responsive app. Before using those, I think you should ask yourself a question.

How do you want to take advantage of more screen space?

Think of regular desktop applications (Word, Photoshop, Visual Studio) or your operating system: when you have more screen available you can have more stuff next to each other. You can have more windows and more panels at the same time. Mostly. Also, but less so, small things get larger (when they benefit from it). It helps to be able to see an entire A4 page when you work with Word. But when you have an Excel sheet with 4 used columns, those don’t use your entire screen just because they can.

Bootstrap tends to create larger space between elements, and larger elements where it is not needed (dropdown <select>, input fields). I say tends to, because if you are good and very careful, you can probably do a better job than I can. But it is not automatic and it is not trivial, to make it good

What I mean is that if my calendar/table looks gorgeous when it is 400px wide, what good does it make to make it larger if the screen gets larger? So I think a better approach to responsiveness is to say that my calendar/table takes 400px. If I have more space available, I can show something else as well.

Mobile Screen Sizes

To complicate things further, mobile phones have different screen sizes, different screen resolutions, and then there are hi-resolution screens that have different virtual and physical resolutions.

So you have your table that looks good on a “standard” mobile with 320px width. What do you want to do if the user has a better/larger screen?

1. make it look exactly the same (just better/larger)?
2. reactively change the way your app looks and works?

If you are opting for (2), I need to wonder why, really?

I argue that if you pick (1) you can make development, testing, documentation and support easier. And your users will have a more consistent experience. At the expense that those with a large mobile may not get the most out of it when using your app.

I propose a simple Mobile First Responsive design

What I propose is not for everyone and everywhere. It may suck for your product and project. That is fine, there are different needs.

I propose a Mobile First (Semi-)Responsive design:

1. Pick a width (320px is fine).
2. Design all parts, all pages, all controllers of your app for that width.
3. On mobile, set the viewport to your width for consistent behaviour on all mobiles.
4. Optionally, on desktop (and possibly tablets), allow pages to open next to each other rather than on top of (and hiding) each other to make some use of more screen when available.

Seems crazy? Please check out my Proof of Concept and decide for yourself! It is only a PoC. It is not a framework, not a working app, not demonstrating Vue best practices, and it is not very pretty. Under Settings (click ?) you can check/change between Desktop, Tablet and Mobile mode (there is a crude auto-discover mechanism in place but it is not perfect). You can obviously try it with “Responsive Design Mode” in your browser and that should work quite fine (except some elements don’t render correctly).

Implementation Details

First, I set (despite this is not normally a recommended thing to do):

<meta id="viewport" name="viewport" content="width=320">

Later I use JavaScript to change this to 640 on a tablet, to allow two columns. Desktops should ignore it.

Second, I use a header div fixed at the top, a footer div fixed at the bottom, and the rest of the page has corresponding margins (top/bottom).

.app_headers {
   position: fixed;
   top: 0;
   left: 0;
 }
 .app_header {
   float: left;
   height: 30px;
   width: 320px;
 }
 .app_footers {
   position: fixed;
   bottom: 0;
   left: 0;
 }
 .app_footer {
   float: left;
   height: 14px;
   width: 320px;
 }
 .app_pages {
   clear: both;
 }
 .app_page {
   margin-top: 30px;
   margin-bottom: 12px;
   width: 320px;
   float: left;
 }

In mobile mode I just add one app_header, app_footer and app_page (div with class). But for Tablets and Desktops I can add more of them (equally many) as the user navigates deeper into the app. It is basically:

<div class="app_headers">
  <div class="app_header">
    Content of first header (to the left)
  </div>
  <div class="app_header">
    Content of second header (to the right)
  </div>
</div>
<div class="app_pages">
  <div class="app_page">
    Content of first page (to the left)
  </div>
  <div class="app_page">
    Content of second page (to the right)
  </div>
</div>
<div class="app_footers">
  <div class="app_footer">
    Content of first footer (to the left)
  </div>
  <div class="app_footer">
    Content of second footer (to the right)
  </div>
</div>

I use little JavaScript to not add too many pages side-by-side should the display/window not be large enough.

It is a good idea to reset margins, paddings and borders to 0 on common items.

I also found that you need a font size of 16px on iPhone, otherwise the Apple mobile Safari browser will immediately zoom when user edits <input> and <select>.

Most effort when I wrote my Proof of Concept was

1. Getting the HTML/CSS right and as simple as possible (I am simply not good enough with HTML/CSS to just get it right)
2. Implementing a “router” that supports this behaviour

Being able to scroll the different pages separately would be possible, a bit more complicated, and perhaps not so desirable.

Conclusions

Exploiting the viewport you can build a web app that works fine on different mobiles, and where the issue with different screen sizes and screen resolution is quite much out of your way.

The site will truly be mobile-first, but with the side-by-side-strategy presented, your users can take advantage of larger screens on non-mobiles as well.

This way, you can build a responsive app, with quite little need for testing on different devices as the app grows. You just need to keep 320px in mind, and have a clear idea about navigating your site.